KERALA JOURNAL OF OPHTHALMOLOGY - KSOS

KERALA JOURNAL OF OPHTHALMOLOGY

VOL. XX ISSUE 2 JUNE 2008

EDITOR
Dr. Meena Chakrabarti

EDITORIAL BOARD EX- OFFICIO MEMBERS
Dr. Rajagopalan Nair (President)
Dr. Charles K. Skariah (Thrissur) Dr. T.A. Alexander
Dr. Rajiv Sukumaran (Kollam) (Immediate Past President)
(Associate Editor) Dr. Sahasranamam
Dr. Valsa Stephen (Trivandrum) (Past Secretary)
Dr. Mini Jayachandran (Kollam)
Dr. Mohammed Haneef (Alapuzha) ADVISORS
Dr. Bindu Das (Kozhikode) Dr. Shobhana Mohandas
Dr. Merine Paul (Thrissur) Dr. Thomas Cherian
Dr. Leila Mohan (Kozhikode) Dr. Sai Kumar S.J.
Dr. Meenakshi Dhar (Kochi) Dr. Giridhar A.
Dr. Amitha Varghese (Thiruvalla)
Dr. Sunil (Kasargode)
Dr. Reena Rasheed (Trivandrum)
Dr. Ashley Thomas (Kozhencherry)

The Kerala Journal of Ophthalmology is the official scientific publication of the Kerala Society of
Ophthalmic Surgeons and 4 issues are published every year.

It welcomes original articles, interesting case reports, update articles, book reviews, journal abstracts
and research papers in Ophthalmology. Dates of the upcoming conferences and CME’s are also published.
Original articles are accepted on condition that they have not been published in any other journal.

SUBSCRIPTION RATE

Annual : Rs. 600 (4 issues)

Single Copy : Rs. 150

Subscription should be sent by demand draft in favour of
Kerala Journal of Ophthalmology payable at Trivandrum

addressed to the Editor, KJO

ADDRESS FOR ALL CORRESPONDENCE: Dr. Meena Chakrabar ti, Editor KJO, Chakrabar ti Eye Care Centre, Kochulloor,
Medical College PO, Trivandrum 695 011, Ph-0471-2555530, 2449599 Fax:- 0471-2558530, E-mail: [email protected]

KERALA SOCIETY OF OPHTHALMIC SURGEONS

(Registered under Societies Registration XXI of 1860. No.387/2003)

President General Secretary Treasurer
Dr. P. Rajagopalan Nair Dr. Sasikumar Dr. Radha Ramanan
Raj Bhavan Ambadi, Adayath Lane, LF Hospital, Angamaly
Palakkad - 676 013 Elamakkara, Kochi 680226 Ernakulam
Ph: 0491-2535676 (R) Ph: 0484-2357135 (H) Ph: 0484 2452546 (H)
Mob: 94476 45676 Mob: 9447475101 Mob: 9447006421

President Elect Vice President Scientific Committee Chairman
Dr. R.R. Varma Dr. B.V. Bhat Dr. Sai Kumar S.J.
Ambikalayam, Warriam Road Asoka Hospital Giridhar Eye Institute
Kochi - 682 016 South Bazar, Kannur Kochi - 682 020
Ph: 0484-2352010 (R) Ph: 0497-2700715 Ph: 0484-2312303 (H)
Mob: 94471 52010 Mob: 94470 11280 Mob: 98470 40840

Joint Secretary Web Site Editor Journal Editor
Dr. Arup Chakrabarti Dr. Thomas George Dr. Meena Chakrabarti
Chakrabarti Eye Care Centre RIO, Red Cross Road Chakrabarti Eye Care Centre
Kochulloor, Trivandrum 695 011 Trivandrum - 695 035 Kochulloor, Trivandrum – 695 011
Ph: 0471-2555530 Mob: 93493 18711 Ph: 0471-2555530
Mob: 9946410540 Mob: 9946410541
Immediate Past Secretary
Immediate Past President Dr. Sahasranamam Dr. Rajesh Radhakrishnan
Dr. T.A. Alexander No. 30, Vinayaka Nagar Palakkad
Thottumughath, Kusumagiri Trivandrum 695 018
Kakkanad, Kochi - 682 030 Ph: 0484-2490421 (R) Dr. Babu Krishnakumar
Ph: 0484-2721161 Mob: 9846020421 Thrissur

Dr. George Thomas Managing Committee Members Dr. Davis Akkara
T.C. 4/1040-1, Near Kowdiar Jn Ernakulam
Trivandrum - 695 003 Dr. Anthrayose Kakkanat
Ph: 0471-2431143, 2433333 Dr. Meena Chakrabarti Dr. C.K. Mathew
Mobile: 9847315150 Alapuzha
Executive Committee Members
Dr. E.J. Mani Dr. Varghese Joseph
Little Flower Hospital Dr. Suresh Babu Pathanamthitta
Angamali - 683 572 Kasargode
Ph: 0484-2608919 Dr. Seshadrinathan
Dr. P.P. Kunhiraman Kottayam
Dr. Alex Joseph Kannur
Leavea Villa Dr. S Venugopal
Gandhi Nagar Dr. Baburaj N.P. Kollam
Peringavu, Thrissur - 680 018 Kozhikode
Tel: 2331199 Dr. Biju John
Dr. Mohammed Swadique Trivandrum
Malappuram

U

K J O CONTENTS

137 EDITORIAL
139
144 “Beyond the IOL”: Will the Cataract Surgeon be Put Out of a Job?
148 Dr. Meena Chakrabarti
151
MAJOR REVIEW
157
Amblyopia- Current Trends in Management
162 Dr. Ramesh Murthy

169 ORIGINAL ARTICLES
174
Is UBM Useful for Zonular Integrity
180 Dr. Meenakshi Dhar, Dr. Abhijeet S. Khake, Dr. H. Sujithra, Dr. Niranjan Pehere
185
Clinical Study of Fungal Corneal Ulcer
Dr. K.V. Raju, Dr. M.S.Vijayalekshmi, Dr. Lakshmi J.

Primary Vitrectomy for Pseudophakic Rhegmatogenous Retinal
Detachment Uncomplicated by Proliferative Vitreoretinopathy
Dr. Meena Chakrabarti, Dr. Valsa Stephen, Dr. Sonia Rani John,
Dr. Arup Chakrabarti

Clinical and Virological Study of Conjunctivitis during the Epidemic in
Calicut (October – December 2006)
Dr. Sheeja Viswanath, Dr. K.S.Chandrakant, Prof (Dr) P. Vijayan,
Prof (Dr) P. Venkitachalam, Dr. Nirupama Balaji, Dr. Tresa Mathew,
Dr. Ramakrishnan

ROP Screening – Analysis of Factors Predictive of Visual Outcome and
Neurodevelopment in Preterm
Dr. Valsa Stephen, Dr. Meena Chakrabarti, Dr. Naveen Jain, Dr. Radhika,
Dr. Sonia Rani John, Dr. Arup Chakrabarti

CURRENT CONCEPTS

Fungal Keratitis
Dr. N. Bindu

OCULAR PHARMACOLOGY

Vital Dyes for Chromovitrectomy: Colours for the Vitreo retinal surgeon!!!
Dr. Meena Chakrabarti, Dr. Valsa.T Stephen, Dr. Sonia Rani John,
Dr. Arup Chakrabarti

OPHTHALMIC INSTRUMENTATION

Ultrasound Evaluation of the Posterior segment of the Eye- A Ready Reckoner
Dr. Mahesh G., Dr. A. Giridhar, Dr. Ramkumar, Dr. Alpesh Rajput

OPHTHALMIC SURGERY

Visual Restoration using Keratoproshesis
Dr. Srinivas K. Rao

K J O CONTENTS

190 PHOTOESSAY
Haemato- oncological Disorders – Ocular Manifestations
192 Dr. Natasha Radhakrishnan, Dr. Lakshmi Nisha Menon, Dr. Gopal. S.Pillai,
Dr. Anuradha Rao
197
201 CONSULTATION SECTION
205 Managing a Cosmetic Blemish
207 Dr. Anil Sreedhar, Dr. Gangadhar Sundar, Dr. Santhosh Hanovar, Dr. KR. Satish,
Dr. Santha Amrith, Dr. Sruthi Tara, Dr. Venkatesh Prabhakaran
210
215 CASE REPORTS
219 Mucormycosis: Genuinely Sight Threatening and Life Threatening
221 Dr. Anuradha. S. Rao, Dr. Lakshmi Nisha Menon, Dr. Indudharan,
223 Dr. Lakshmi C, Dr. J. Jisha Vimoj
225 Drug Induced Retinopathies
Dr. N. Sandhya, Dr. A. Giridhar, Dr. Maheh. G, Dr. S.J. Saikumar
Self Inflicted Bilateral Rupture Globe Resulting in Total Permanent loss of
Vision- A Case report.
Dr. P.S. Girija Devi, Dr. A.Reena, Dr. Jasmine LB
An Unsolicited Guest- Ocular Larva Migrains by Angiostrongylus Cantonensis.
Dr. Valsa Stephen, Dr. Sonia Rani John, Dr. Meena Chakrabarti,
Dr. Arup Chakrabarti

COMMUNITY OPHTAHLMOLOGY
Professional Liability and Adjudicative Process
Dr. K. Prema

JOURNAL REVIEW

BOOK REVIEW

CME PROGRAMMES

PG TEAR SHEET

INSTRUCTIONS TO AUTHORS

EDITORIAL

“Beyond The IOL”: Will the Cataract
Surgeon Be Put Out of a Job?

Implanting IOLs has become a way of life for many cataract surgeons – a routine uncomplicated
operation that dramatically restores vision and improves the quality of life of millions of patients
world wide. However a change in the wind by way of preliminary results of research on “dissolving
cataracts”, and “growing your own lens” are in the pipeline and may become a cause for cataract
surgeons to panic! How close are we to a world beyond the IOL…….. where cataracts can be
dissolved and the lens replaced with a new one grown from stem cells? 1

Way back in the December of 2003, the British newspaper The Daily Mail splashed in its headlines,
the discovery by Russian Scientist of “ eye drops that dissolved cataract” in a matter of few
weeks. This revolutionary treatment gained popularity in Europe after being featured in a
television show. Eltros Gmbh Schweiz, the Swiss manufacturer claimed that this could mean an
end to cataract surgery ! Their product called Ethos Endymion “Bright Eyes” 2 used a special
derivative of the naturally occurring neuropeptide L- Carnosine also called N- Acetyl Carnosine
(NAC) which is a super antioxidant and antiglycating agent. Clinical trails carried out claimed
efficacy in dissolving 100 % of primary senile immature cataract and 80 % of mature cataracts
over a 6 month period with sustainable results 24 months later. The product was advertised as
“Bright Eyes: a simple inexpensive course of eye drops to dissolve cataracts as opposed to invasive
surgery” and was marketed at 100 Swiss Francs/ box of 5 vials each containing 2 ml of the
drops.

N- Acetyl Carnosine (NAC) 2 the chemical component of this eye drop was later stripped of its
magical cataract dissolving powers. Interest in eye drops to cure cataract was reawakened in
mid 2007 when Dr. Randall. J. Olson3 of Moran Eye Centre, University of Utah presented evidence
that a formulation of the heavy metal chelator EDTA had the power to dissolve cataract. The
phase I and phase II FDA trials showed positive results. The topical treatment appeared to ‘clear’
multi lamellar bodies found 10 times more frequently in cataract than in normal lenses.

The results of the phase III trials will definitely tell us whether a permeabilised formulation of
EDTA is here to stay or will follow the same disastrous journey of N- Acetyl Carnosine.

Results of the several new studies have shown that you may be able to “grow your own lens”
after cataract surgery. The possibility of lens re-growth is by no means restricted to newts, other
amphibians and fish - mammals including man have been known to regrow lens tissue after
cataract removal. Regrowth as we all know definitely occurs – only rarely is clear lens tissue
regenerated. More frequently the new lens fibres are chaotically organized and opaque and
serves no useful visual purpose.

138 Kerala Journal of Ophthalmology Vol. XX, No. 2

For the past two decades Dr. Gwon 4, 5 from the university of California has been experimenting
with various methods of encouraging regrowth of clear lens fibers across the capsular bag.
Inflating the capsular bag after phacoemulsifiaction with air or any other material, to keep the
walls of the capsule taut and to prevent them from sticking together is the first step. Beyond that
Dr. Gwon’s research has focused in providing a suitable scaffold to entrain fiber-cell growth
encouraging regular parallel growth characteristics of a clear lens. Most effective results were
obtained when hyaluronic acid was used as scaffold.

Using this scaffold Dr. Gwon has successfully re-grown a clear lens in rabbits at least a couple of
times! However there are plenty of hurdles to overcome. The rate of regrowth is frustratingly
slow and may be expected to be even slower in elderly patients. The second technical difficulty
involves removing the hyaluronic acid scaffold after a few weeks. Reaserch is underway using
hyaluronidase - a technically demanding procedure - to dissolve the scaffold!!

So the logical conclusion to this is to ponder whether the time has comes for the cataract surgeon
to panic? When will this “world beyond IOL” put cataract surgeons out of jobs? There are promising
evidences that powerful topical application may block cataractogenesis and dissolve existing
cataracts. Acceptance of this mode of therapy by ophthalmologists will depend on the result of
phase III trial. This may be years ahead and will be applicable to only a few types of cataracts.

Lens regrowth will be at least a decade before realization and will still require an accomplished
cataract surgeon to perform the phacoemulsification and may be it will turn out to be a more
interesting job than the standard phacoemulsifiaction with IOL implantation.

References

1. Nick Lane PhD, Beyond the IOL Eurotimes, Vol 12 Issue 9, Sept 2007.
2. Bright eyes drops for pets and for people; www.google.com
3. Rendall, J. Olson; ASCRS 2007.
4. A E Gown et al. A Histologic study of lens regeneration in aphakic rabbits Investigative Ophthalmology

Vis Sci 1990; 31 (3): 540-547
5. A E Gwon et al. Lens regeneration in juveniles and adult rabbits measured by image analysis. Invest

Ophthalmol Vis Sci 1992; 33(7) : 2279-2283.

Dr. Meena Chakrabarti MS DO DNB
Editor

June 2008 Kerala Journal of Ophthalmology 139

MAJOR
REVIEW

Amblyopia - Current Trends in Management

Dr. Ramesh Murthy MD FRCS

Introduction to screen amblyopia has been a matter of debate. In
the Avon longitudinal study of parents and children,
The detection and management of amblyopia lies at an assessment of the effectiveness of early treatment
the heart of pediatric ophthalmology. As John T Flynn of amblyopia was performed. It was noted that intensive
noted in the 17th annual Frank Costenbader lecture screening protocol at a young age resulted in better
“it is to amblyopia to which my heart returns” 1. Till amblyopic eye acuity at 7.5 years of age in those who
recently, literature on amblyopia consisted underwent screening 4. A Cochrane review on the value
predominantly of retrospective reviews. In 1997, the of programmes for screening showed that the lack of
pediatric eye disease investigator group (PEDIG) was data from randomized trials makes it difficult to analyse
formed to conduct clinical research in eye disorders the impact of existing screening programmes on the
affecting children. The studies were conducted through prevalence of amblyopia. This does not imply that vision
simple protocols with limited data collection and screening is not beneficial, but that the intervention
implemented by both university and community based has not been tested in robust trials 5.
pediatric eye care practitioners as part of their routine
practice. Amblyopia is the most common cause of Neuronal Basis of Amblyopia
monocular visual impairment in children and young
and middle aged adults and hence PEDIG has laid The visual processing system is susceptible to the
emphasis on studies of treatment modalities of influences of abnormal environmental factors. The seat
amblyopia, the Amblyopia Treatment Studies. of amblyopia is not the retina but the striate and the
extrastriate cortex. The effects on the lateral geniculate
Definition nucleus are minimal 6. The cells of the layer 1,4,6 from
the contralateral and 2,3,5 from the ipsilateral eye can
Amblyopia has been defined as corrected visual acuity be affected if monocular deprivation occurs early. There
of > 20/40 or > 1 line difference in corrected visual were two sets of synaptic inputs and with experience
acuity between the 2 eyes. This is not a result of any one pathway from the open eye takes over preempting
organic problem of the eye or the visual pathway 2. the territory of the closed eye.

Prevalence In the visual cortex, the principal abnormality is at the
level of the primary visual cortex (striate cortex, V1,
The prevalence of amblyopia in the age group 4 years Brodmann’s area 17) 6. Normally eye inputs to the area
has been reported to be 1.07 % in the population IV C are divided equally between the eyes. The deprived
screened at infancy, to 2.57 % in the population that eye shows a marked shrinkage of its input stripes
has not been screened at infancy 3. The optimal timing (ocular dominance columns) and a corresponding
expansion of the nondeprived eye 7. Radioactive
Dept. of Oculoplasty and Ocular Oncology, L V Prasad Eye Institute, Hyderabad aminoacids and axonal transport from eye to cortex
Email: [email protected]

140 Kerala Journal of Ophthalmology Vol. XX, No. 2

shows a marked shrinkage of the input stripes (ocular this prospective randomized multicenter clinical trial,
dominance columns) and a corresponding expansion moderate amblyopes (20/40 to 20/100) in the age
of the non deprived eye. In addition to the differential group 3 to 7 years were included. 419 patients with an
retraction of terminals, the result is produced by average age of 5.3 years were enrolled. 96% completed
sprouting of axonal terminals. Changes in the area V1 examination at 6 months. The atropine group received
are qualitatively related to the depth of amblyopia. 1 drop of 1 % atropine in the sound eye daily. If by
Changes in V1 typically predict smaller deficit than 4 months, acuity had not reached 20/30 or improved
measured behaviourally. Qualitatively abnormalities in by 3 lines from baseline, distance correction was
the eye dominance columns and the spatial properties removed to augment atropine effect. Patching group
of visual cortex neurons were related on a case by case was prescribed minimum 6 hours patching daily, if by
basis to the depth of amblyopia. Quantitative analysis 4 months they had not reached 20/30 or improved by
suggests that these abnormalities alone do not explain 3 lines from baseline, full time patching was prescribed.
the full range of visual deficits in amblyopia and there The mean visual acuity in the amblyopic eye at
may be unknown abnormalities in the extrastriate enrolment was 20/63 with a mean difference of 4.4
cortex 8. The suggested mechanisms of visual loss in lines between eyes. Visual acuity improved 3.16 lines
amblyopia include abnormal neural response in the patching group and 2.84 lines in the atropine
properties, poor synchronization of neuronal responses, group. Improvement initially was faster in the patching
abnormal topographic representation of topographic group, but at 6 months difference in acuity between
receptive fields and undersampling of visual space 9. the 2 groups was clinically insignificant. At 6 months,
At the molecular level, synaptogenesis determines the 79 % in patching group and 74 % in the atropine group
loss of vision and improvement in amblyopia 1. had acuity 20/30 or better and /or improvement from
If performed early in the critical period, patching the baseline by 3 lines. The conclusions were both treatments
good eye can lead to a complete switch in fixation were well tolerated, though atropine had more
preference 1. The geniculate innervation of layer IVC tolerability and patching works faster than atropine 11.
reverses and the initially deprived eye can take over
much of the lower part of layer IVC, but fails to reverse A 2 year follow up of the same study group to look at
the domination of the other eye in the upper part of the long term follow up revealed that the improvement
layer IVC. The critical period is different for different was 3.6 lines in the atropine group and 3.7 lines in the
cell types. Even after prolonged patching the loss of patching group. In moderate amblyopia, atropine and
binocular cells may not reverse and there may be patching both showed moderate improvement.
permanent loss of stereopsis. The risk associated with The amblyopic eye acuity was also noted to be 2 lines
unilateral patching or alternate patching is the loss of less than the worse eye. This study gave concrete
stereopsis and not fusion. Levodopa can help in the evidence about the well known aspects of atropine and
improvement of visual acuity and pattern VEP patching 12.
amplitudes 10. Cytidine 5' diphosphocholine also
improves visual acuity, contrast sensitivity and visual Part time occlusion
evoked potentials of amblyopic subjects. Functional MRI
a relatively new modality may reveal changes which Patching regimens used to be divided into full time
can be used to assess the effect of amblyopia treatment patch for days depending on the age. Compliance and
in humans. the risk of occlusion amblyopia was an issue with these
regimens. The ATS 2A (amblyopia treatment study 2A)
Recent Concepts in Management compared 6 hours versus full time patching for severe
amblyopia (20/100 to 20/400) in children 3 to 7 years
Atropine versus patching old. In this prospective study 175 patients were enrolled
with an average age of 4.8 years. The severe amblyopic
This was studied in the first PEDIG trial (amblyopia patients were randomized to 6 hours or full time (all
treatment study 1). The objective was to compare but 1 waking hour daily patching). The mean acuity at
patching of the sound eye with atropine instillation. In enrolment was 20/160, with a mean difference in acuity
between the eyes of 7.8 lines. The 4 months follow up

June 2008 Ramesh Murthy - Amblyopia 141

was completed by 90 % patients. Mean improvement Older children
in the visual acuity was 4.8 lines in the 6 hour group
and 4.7 lines in the full time group. At 4 months there The amblyopia treatment study 3, ATS 3, evaluated the
was no difference in acuity between the groups. 86 % effectiveness of treatment in children aged 7 to 17 years.
of the patients in the 6 hour group and 82 % in the full In this prospective randomized clinical trial, 507
time group had improvement in acuity of more than patients were studied with a visual acuity ranging from
3 lines from baseline. This study formed the basis for a 20/40 to 20/400. The optimal optical correction was
paradigm shift from full time daily patching routines given followed by randomization to treatment group
to part time occlusion.13 (2-6 hours per day of prescribed patching combined
with near visual activities for all patients plus atropine
The amblyopia treatment study (ATS 2B), compared sulphate for children aged 7 to 12 years) or optical
2 hours versus 6 hours of daily patching for moderate correction alone. With treatment 53 % responded and
amblyopia in children aged 3 to 7 years old. In this with optical correction 25 % responded. For patients
prospective study 189 patients were enrolled with a aged 7 to 12 years, 2 to 6 hours of patching with near
mean visual acuity of 20/63 and randomized to 2 or 6 visual activities and atropine improves the visual acuity
hours of patching. Visual acuity improved in both even if the amblyopia has been previously treated. For
groups and at 4 months there was no difference patients aged 13 to 17 years, 2 to 6 hours of patching
between the 2 groups. 62 % of patients in each group per day with near visual activities may improve when
had a visual acuity 20/30 or better and or improvement amblyopia has not been previously treated, but is of
of 3 lines. It was noted that prescribing greater hours little benefit if amblyopia was previously treated with
of patching did not seem to have a significant beneficial patching 19.
effect in the first 4 months of treatment. It was also
noted that the hours of patching did not affect the rate Optical correction
of improvement .14-17
A study was conducted to evaluate the results of 2 hours
Recurrence of amblyopia after discontinuation of daily patching for amblyopia in children aged 3 to 7
of treatment years old. There were 2 phases (1) spectacle phase in
which maximum improvement with spectacles was
The amblyopia treatment study 2C was undertaken to noted and the (2) randomized trial comparing a group
study the recurrence of amblyopia after discontinuation using patching treatment and spectacles with a control
of treatment. In this prospective trial, 156 children less group using spectacle correction alone. In the spectacle
than 8 years of age, who received continuous treatment phase 84 children with anisometropia were enrolled
for amblyopia for the previous 3 months ( prescribed and in the randomized trial there were 180 children.
at least 2 hours of daily patching or at least 1 drop of In the randomized trial group, children were assigned
atropine per week) and who had improved at least to either 2 hours of daily patching with 1 hour of near
3 log MAR levels of treatment. Follow up was performed visual activities or spectacles alone. 96 % patients were
at 52 weeks to assess the recurrence of amblyopia seen after 5 weeks. With optical correction alone
defined as 2 or more log MAR line reduction of visual amblyopia improved in 77 % of the patients and
acuity from enrolment, confirmed by a second resolved in 27 %. In the randomized group, visual acuity
examination or restarting of treatment due to a 2 or improvement from baseline to best measured visual
more log MAR level reduction of visual acuity. acuity at any visit averaged 2.2 lines in the patching
Approximately one fourth of the children were noted group and 1.3 lines in the control group. Following
to have a recurrence of amblyopia in the first year post treatment with spectacles, 2 hours of daily patching
treatment. This is similar in the patching and atropine combined with 1 hour of near visual activities modestly
group. In patients with intense patching (6-8 hours per improves moderate to severe amblyopia in children 3
day), recurrence was more common when the to 7 years old .20-21
treatment was not reduced prior to cessation, than
when treatment was reduced to 2 hours per day prior In another study on the treatment of bilateral refractive
to cessation 18. amblyopia in children 3 to less than 10 years of age,

142 Kerala Journal of Ophthalmology Vol. XX, No. 2

113 children with previously untreated bilateral improvement occurred within 6 weeks. Treatment
refractive amblyopia were treated with optimal outcome was significantly better for children < 4 years
spectacle correction. Bilateral refractive amblyopia was of age than those older than 6 years 24.
defined as 20/40 to 20/400 best corrected binocular
visual acuity in the presence of 4 diopters or more The PEDIG studies suggested radical changes in the
hypermetropia by spherical equivalent, 2 diopters or management protocols for amblyopia. It is interesting
more of astigmatism or both in each eye. There was that another study was conducted to see the effect of
improvement in visual acuity by 3.4 lines in the group the randomized trial of patching regimens for treatment
with visual acuity 20/40 to 20/80 and 6.3 lines in the of moderate amblyopia on pediatric ophthalmologists.
group 20/100 to 20/320. The probability of a binocular Two questionnaires were mailed one in 2003 and one
visual acuity of 20/25 or better was 74 % at 52 weeks. in 2006 to 560 members of the American Association
The conclusion of this study was treatment of bilateral for Pediatric Ophthalmology and Strabismus. Of the
refractive amblyopia with spectacle correction improves 107 responses (20 %) received, it was noted that 55 %
binocular visual acuity in children 3 to less than of the respondents had decreased their prescribed
10 years of age 22. patching regimens as compared to 28 % in 2003. There
was no significant increase in the prescription of near
Role of near activities visual activities or only a 2 hour patching regimen 25.

A study was designed to determine whether children Conclusions
randomized to near or non-near activities would
perform prescribed activities and to obtain a preliminary These studies conducted by PEDIG put forth new ideas
estimate of the effect of near versus non near activities and concepts in the management of amblyopia based
on amblyopic eye visual acuity when combined with on prospective trials. The conclusions of the various
2 hours of daily patching. In this study 64 children in studies have been summarized below.
the age group of 3 to < 7 years were randomly assigned
to receive either 2 hours of daily patching with near z Patching works faster than atropine, however at
activities or 2 hours of daily patching without near 6 months the improvement is the same with
activities. Parents completed daily calendars for patching and atropine in moderate amblyopes.
4 weeks. After 4 weeks, there was greater improvement
in the amblyopic eye visual acuity in those assigned to z Improvement with full time and 6 hours patching
near visual activities. Children patched and instructed similar in severe amblyopes.
to perform near activities for amblyopia spent more
time performing those near activities compared to z In moderate amblyopes 2 hours patching gives
children not instructed. Performing near activities while similar results to 6 hours of patching.
patching may be beneficial in treating amblyopia 23.
z About 25 % of the children have a recurrence of
Dose response relationship amblyopia in the first year post treatment.

In this study the dose-response relationship for z Recurrence is less common when patching was
amblyopia therapy was studied. There were 3 distinct tapered to 2 hours per day before stopping.
phases – baseline: to measure visual status, refractive
adaptation: an 18 week period of spectacle wear with z In patients 7 to 12 years of age, visual acuity
6 weekly measurements of logMAR visual acuity, improves with treatment even if amblyopia has
occlusion: participants prescribed 6 hours of patching been previously treated; in the 13 to 17 year age
per day. Patching was monitored using a dose response group, there may be little benefit if the amblyopia
monitor attached to the patch. The average has been previously treated.
concordance with patching was 48 %. Increasing the
dose rate beyond 2 hours per day hastened the response z Refractive correction improves visual acuity in
but did not improve outcome. More than 80 % of the untreated anisometropic amblyopia

z Most cases of moderate amblyopia (20/40 to
20/100) resolve.

z Performing near activities while patching may be
beneficial in treating amblyopia.

June 2008 Ramesh Murthy - Amblyopia 143

z Bilateral refractive amblyopia can be treated with 13. Holmes JM, Kraker RT, Beck RW, et al. A randomized
spectacle correction with remarkable improvement trial of patching regimens for treatment of severe
of visual acuity. amblyopia in children. Ophthalmology 2003;110:
2075-2087.
z Maximum improvement with therapy occurs in the
first 6 weeks. 14. Pediatric Eye Disease Investigator Group. A randomized
trial of atropine versus patching for treatment of
z Younger the child better the outcome. moderate amblyopia in children. Arch Ophthalmol
2002;120:268-78.
References
15. Pediatric Eye Disease Investigator Group. A comparison
1. Flynn JT. Amblyopia revisited. J POS 1991, 28: 183-201. of atropine and patching treatments for moderate
2. Eibschitz-Tsimhoni M, Friedman T, Naor J, Eibschitz N, amblyopia by patient age, cause of amblyopia, depth
of amblyopia and other factors. Ophthalmology
Friedman Z. Early screening for amblyogenic risk factors 2003;110:1632-1638.
lowers the prevalence and severity of amblyopia. J
AAPOS 2000; 4(4): 194-9. 16. Pediatric Eye Disease Investigator Group. The clinical
3. Angi MR, Pucci V, Forattini F, Formentin PA, Results of profile of moderate amblyopia in children younger than
photrefractometric screening for amblyogenic defects 7 years. Arch Ophthalmol 2002; 120:281-287.
in children aged 20 months. Behav Brain Res.1992
31;49(1):91-7. 17. Pediatric Eye Disease Investigator Group. The course
4. Williams C, Northstone K, Harrad RA, et al. Amblyopia of moderate amblyopia treated with atropine in
treatment outcomes after screening before or at age children: experience of the amblyopia treatment study.
3 years: followup from randomised trial. BMJ 2002,324: Am J Ophthalmol 2003;136:630-639.
1549-1551.
5. Powell C, Porooshani H, BohorquezM, Richardson S. 18. Pediatric Eye Disease Investigator Group. Risk of
Screening for amblyopia in childhood. Cochrane amblyopia recurrence after cessation of treatment. J
database syst rev. 2005, 20(3):CD005020. AAPOS 2004;8:420-8.
6. Grigg J, Thomas R, Billson F. Neuronal basis of amblyopia:
a review. Indian J Ophthalmol. 1996;44: 69-76. 19. Pediatric Eye Disease Investigator Group. Randomised
7. Flynn T. 17th annual Frank Costenbader Lecture. trial of treatment of amblyopia in children 7 to 17 years.
Amblyopia revisited. J Pediatr Ophthalmol Strabismus Arch Ophthalmol 2005;123:437-447.
1991;28:183-201.
8. Kiorpes L, Kiper DC, O’Keefe LP, Cavanagh JR, Movshon 20. Pediatric Eye Disease Investigator Group. Treatment of
JA. Neuronal correlates of amblyopia in the visual cortex anisometropic amblyopia in children with refractive
of macaque monkeys with experimental strabismus and correction. Ophthalmology 2006;113:895-903.
anisometropia. J Neurosci 1998;18:6411-24.
9. Kiorpes L, Mc Kee SP. Neural mechanisms underlying 21. Pediatric Eye Disease Investigator Group. A randomized
amblyopia. Curr Opin Neurobiol 1999;9:480-6. trial to evaluate 2 hours of daily patching for strabismic
10. Basmak H, Yildrim N, Erdinc O, Yurdakul S, Ozdemir and anisometropic amblyopia in children.
G. Effect of levodopa therapy on visual evoked potentials Ophthalmology 2006;113:904-12.
and visual acuity in amblyopia. Ophthalmologica
1999;213:110-3. 22. Wallace DK, Chandler DL, Beck RW, et al. Treatment of
11. Beck RW. The Pediatric Eye Disease Investigator Group. bilateral refractive amblyopia in children three to less
J AAPOS 1998;2:255-256. than 10 years of age. Am J Ophthalmol 2007;144:
12. Repka MX, Wallace DK, Beck RW, Pediatric Eye Disease 487-496.
Investigator Group. Two-year follow-up of a 6-month
randomized trial of atropine vs patching for treatment 23. Pediatric Eye Disease Investigator Group. A randomized
of moderate amblyopia in children. Arch Ophthalmol. pilot study of near activities versus non-near activities
2005 Feb;123(2):149-57. during patching therapy for amblyopia. J AAPOS
2005;9(2):129-36

24. Stewart CE, Moseley MJ, Stephens DA, et al. Treatment
dose-response in amblyopia therapy: the monitored
occlusion treatment of amblyopia study(MOTAS). Invest
Ophthalmol Vis Sci 2004;45(9):3048-54.

25. Wygnanski-Jaffe T, Levin AV. The effect of the
randomized trial of patching regimnes for treatment of
moderate amblyopia on pediatric ophthalmologists: 3
year outcome. J AAPOS 2007;11:469-472.

144 Kerala Journal of Ophthalmology Vol. XX, No. 2

ORIGINAL
ARTICLE

Is UBM Useful For Zonular Intergrity?

Dr. Meenakshi Dhar MS, Dr. Abhijeet S. Khake, Dr. H. Sujithra DO, Dr. Niranjan Pehere

Abstract

We conducted a study of ultrasound biomicroscopy[UBM] for 50 patients with mature senile
cataract, pseudoexfoliation, trauma, or those with clinical suspicion of zonular
dehiscence[n=5]. 10 had clinical zonular dialysis with phacodonesis /iridodonesis which
was confirmed by UBM. Three patients were noted to have zonular dehiscence on UBM.
Areas of zonular dehiscence were mapped on UBM and the UBM findings are described.
Surgery could be planned accordingly and complications prevented. Sensitivity for preoperative
detection of zonular loss is high with UBM. Surgical surprises can thus be avoided and better
visual outcomes ensured.

Key words Zonular dehiscence, subluxation, ultrasound biomicroscopy

Introduction needs to be taken, and only low fluid phaco maneuvers
are carried out, and abrupt shallowing or deepening of
One of the challenging situations in cataract scenario the anterior chamber are to be avoided.
with an unpredictable outcome despite advances in
cataract surgery, even in the hands of well trained With UBM one gets images of cross sections of the intact
phacosurgeons is zonular dehiscence. Such situations anterior globe at microscopic resolution. It uses a high
can be more enigmatic especially in hard cataracts as frequency ultrasound transducers (50 MHz), with a
these pupils usually fail to dilate. resolution of 20 μm, and structures upto a depth of
4 mm can be seen.
Ultrasound biomicroscopy [UBM] has come as a boon
for visualizing structures in the angle of anterior Occult zonular defects identified preoperatively enabled
chamber and the ciliary body area. The location of the modification of surgical technique to ensure improved
ciliary processes and the integrity of the zonules can outcomes.
now be assessed, thus enabling preoperative detection
of subtle degrees of subluxation. Occult zonular defects Materials and Methods
detected preoperatively, can be managed more
effectively. Preventive measures can be taken to ensure We selected patients coming for cataract evaluation and
maximum bag stability. These include, avoiding management to the Out Patient Clinic of the
pressure or massage after the peribulbar block, giving Ophthalmology Department at Amrita Institute of
I/V Mannitol to decrease vitreous up-thrust. Extra care Medical Sciences between Oct. 2006 and Oct. 2007.
Consecutive cataract patients with mature cataract or
Amrita Institute of Medical Sciences & Research Centre, Edapally, Cochin, 682026 pseudoexfoliation syndrome or those with history of
Email [email protected] trauma were included in the study.

June 2008 M. Dhar et al. - UBM in Cataracts 145

All patients underwent a comprehensive ophthalmic Observations
evaluation including vision assessment, refraction, slit
lamp biomicroscopy, fundus examination (unless the Of the 50 patients undergoing UBM, zonular dehiscence
cataract was mature) keratometry, and biometry for was seen in 13 patients. Positioning of the probe was
IOL calculation. very important and it had a long learning curve with
fibre orientation being perpendicular to the probe. The
In addition, a UBM was done for these patients in an oscillations of the UBM scan had strict radial orientation
undilated pupil using the UBM machine from Appasamy towards the limbus.
with the 35 MHz and 50 MHz probe, a scan angle of
10-30 degrees. The probe was aligned radially along Seven patients had clinical zonular dialysis in one eye,
the 12 clock hours placed perpendicularly over the and the other eye was normal.
cornea so as to include the angle of anterior chamber,
iris, the ciliary body, zonules and peripheral lens edge. Area of zonular absence as seen by UBM was less than/
= 1 quadrant in 5 cases, 3 at 1 site only & 2 at two
Scanning was performed under topical anesthesia using sites. The other 2 cases had almost 1800 dehiscence.
a 20 mm eye cup which was inserted between the lids
and filled with saline/Ringer solution, with the patient Table 1: Clinical details
in a supine position in standardized room lighting
conditions. Patients undergoing Clinically Zonular Zonular
Surgery diagnosed loss, detected
Initial scan was done over the central anterior chamber UBM [n=50] defect onUBM
to observe for any tilt of the bright reflective line of the
anterior lens capsule. Scanning was then done over the [n=10] [n=13]
iris root for 3600 to assess zonules directly.
Coloboma 3 33
Radial scanning was performed with probe oscillations Trauma 4 11
parallel to the zonules & with the focal plane of the Pseudoexfoliation 19 24
transducer at the depth of the zonules. MSC/ HMSC [Fig.1] 33 23
Homocystinuria [fig2] 1 11
To prevent a false impression of zonular defect, the Marfan’s Syndrome[Fig.3] 1 11
long axis of the transducer was kept perpendicular to
the zonular fibres, helped by asking the patient to 3 patients had anterior coloboma in both the eyes with
position the eye accordingly. both iris and lenticular coloboma. There was absence
of zonules on UBM in the colobomatous
In view of the familiarity with discussing the anterior areas, and the remaining zonules were found to be
segment in terms of clock hours, we recorded zonular firm and normal. Extent of zonular absence was
defects in terms of clock hours as well. Beginning radial noted in clock hours for each of the eyes. In all
scanning at 12 o’clock position, we carried it out in colobomas, the zonular absence was in an area larger
clockwise fashion till 6 o’clock position with the probe than the iris coloboma of the same eye. The maximum
marker toward the limbal side. extent of coloboma was 2700 (n=1) and
minimum<900(n=2). Ultrasound biomicroscopy of the
Then the marker was located toward the corneal side lens “Coloboma” revealed a greatly increased sphericity
from 6 to 12 o’clock position for each eye. of the lens and the deficiency of zonules in the
“colobomatous” area.
All these patients subsequently underwent cataract
surgery and the UBM findings were correlated with the Capsular tension ring was used effectively in these
intraoperative observations. patients increasing capsular bag stability during both
phacoemulsification and IOL placement. The CTR was
In those with zonular dehiscence detected clinically or inserted by hand over hand method
with UBM a capsular tension ring was inserted during
the procedure. The visual and surgical outcomes were One patient gave a history of unilateral blunt trauma
analysed. with history of a coconut falling on her a few
years ago. She was found to have subluxation clinically
with iridodonesis, shallow anterior chamber
superiorly and a pupil that did not dilate. This was

146 Kerala Journal of Ophthalmology Vol. XX, No. 2

confirmed on UBM. Zonules were missing for 1800, the lenticular sphericity was increased in the area of zonular
ciliary body was flattened and increased lenticular defects [n=3] (fig.1). Other effects seen were pupillary
sphericity was noted. block, angle crowding and direct iridal irritation. Angle
of anterior chamber was increased [Fig. 5] in a patient
Of the 19 patients with pseudoexfoliation [PXE], two with posterior subluxation.
had iridodonesis, of which one had phacodonesis as
well. On UBM, 4 patients with PXE had zonular
dehiscence evidenced by absence of zonules and
localized increase in lenticular sphericity.

Occult zonular loss was detected in 3 patients on UBM.
In 2 others with mature/hypermature cataract with
iridodonesis the zonular dialysis was confirmed with
UBM. There were either missing zonules[n=2], or/and
zonules were stretched[n=2] (fig. 3and 4), and/or
ciliary body flattening [n=2] was observed. The

Fig. 3. Increase in anterior chamber depth, stretched zonules
and lens flattened in patient of Marfan’s syndrome
with subluxation on UBM

Fig. 1. Clumping of ciliary body processes and zonules in
the right half of the field, increase in anteroposterior
diameter of the lens -Indication of subtle subluxation
in a mature cataract

Fig. 4. UBM of a patient with stretched zonules

Fig. 2. UBM of a homocystenuria patient with B/L Fig 5 Large angle of anterior chamber 51deg.on UBM in a
subluxation, managed conservatively with once daily patient with post subluxation
instillation of Pilocarpine. The UBM shows deepening
of AC with widening of the angle

June 2008 M. Dhar et al. - UBM in Cataracts 147

One patient with homocystinura, had bilateral high One unique feature was the deposition of granular
myopia with subluxation and mildly raised IOP. It was material on the zonules in PXE. This has been noted
managed conservatively. Patient had best corrected earlier, and depending on the extent has been classified
visual acuity (BCVA) of 6/9 in both eyes. She was on into mild, moderate and severe cases. There are
Pilocarpine 2 % twice daily as the zonular dialysis was diagnostic criteria proposed by the Japanese for the
>180 degrees in both the eyes. The extent of zonular early detection of PXE, based on the changes found in
defect found on UBM was higher than that seen the zonules by UBM.
clinically in a dilated pupil. The anterior chamber on
UBM was found deep with iris falling backward with The preoperative diagnosis of the zonular defect can
no support. No zonules or lens was seen in this area help in judging the appropriate timing of intervention.
with flattening of ciliary body [Fig.4]. In the presence of large zonular defect, it is better not
to wait till cataract is more significant in a patient with
Discussion extensive zonular damage.

Patients more prone to zonular dehiscence and Conclusion
subluxation are, those with pseudoexfoliation and
hypermature cataracts in the senile age group. Also an Ultrasound biomicroscopy is a sensitive and accurate
unsuspecting, mild blunt trauma, might cause zonular method of assessing zonular dehiscence, although there
dehiscence, an event the patient may have well is a long learning curve in mastering the technique.
forgotten about. The UBM can today come to the rescue The orientation of the probe is important, otherwise
for the unsuspecting surgeon, and help in the diagnosis false negative results may be high, i.e. the zonular defect
of zonular defects. The surgeon needs to have a high may be missed. UBM can image zonules in patients
degree of suspicion. Certain perioperative maneuvers suspected to have zonular dehiscence, allowing a
can enhance the degree of subluxation, increasing the prepared approach to careful surgery for these patients,
risk of dreaded complications like nucleus drop or The CTR insertion ensures good stability both for the
vitreous prolapse. The safe placement of the PCIOL was procedure of the cataract surgery as well as for the
impossible in these cases, until the capsular tension long term placement of the intraocular lens in the bag.
ring started being used for subluxated lenses almost a
decade ago. Bibliography

Certain steps taken during surgery can ensure a 1. Ludwig K, Wegscheider E, Hoops JP, Kampik A.
favourable outcome. These include gentle pressure if In vivo imaging of the human zonular apparatus
peribular is given, Preferably giving I/V Mannitol to with high-resolution ultrasound biomicroscopy. Graefes
minimize vitreous upthurst, and gentle steady Arch Clin Exp Ophthalmol. 1999 May;237(5):
manipulation of globe. The incision is to be made away 361-71.
from site of zonular defect and if possible opposite to
it. The initiation of rhexis is difficult in subluxated lenses 2. Agarwal T, Saxena R, Vajpayee RB. Ultrasound
and this step may be an important subtle indicator of biomicroscopy in lens “coloboma”. Eur J Ophthalmol.
an undetected zonular weakness. The rhexis should be 2003 May;13(4):390-1.
initiated in an area of intact zonules so that counter
traction is avoided. It should be small and central, with 3. McWhae JA, Crichton AC, Rinke M Ultrasound
slow careful hydrodissection at multipe sites. The use biomicroscopy for the assessment of zonules after ocular
of capsular tension rings has of course revolutionized trauma. Ophthalmology. 2003 Jul;110(7):1340-3
the outcome, combined with the availability of
dispersive and cohesive viscoelastics. At all steps sudden 4. Inazumi K, Takahashi D, Taniguchi T, Yamamoto T.
shallowing of the anterior chamber as well as deepening Ultrasound biomicroscopic classification of zonules in
are to be avoided. Phaco chop is the preferred method exfoliation syndrome. Jpn J Ophthalmol. 2002
with adequate power and not a high flow rate. Sep-Oct;46(5):502-9

5. Arbisser LB. Managing intraoperative complications in
cataract surgery. Curr Opin Ophthalmol. 2004
Feb;15(1):33-9

6. Pavlin CJ, Buys YM, Pathmanathan T Imaging zonular
abnormalities using ultrasound biomicroscopy. Arch
Ophthalmol. 1998 Jul;116(7):854-7

148 Kerala Journal of Ophthalmology Vol. XX, No. 2

ORIGINAL
ARTICLE

Clinical Study of Fungal Corneal Ulcer

Dr. K.V. Raju MS, Dr. M.S. Vijayalakshmi MS, Dr. Lakshmi J.

Abstract

Aim: To study the epidemiology of fungal corneal ulcers in relation to age, sex, mode of
injury, clinical presentation, etiology and the response to treatment with topical and systemic
antifungal medications.

Procedure: 30 patients who were found positive for KOH and / or fungal culture during a
period of one year attending the Ophthalmology outpatients department, Medical College,
Kozhikode were studied.

Introduction serious ocular infection, which requires urgent
diagnosis and appropriate treatment. Blindness due to
Mycotic keratitis is an important ophthalmologic mycotic keratitis can be prevented by early intervention.
problem causing preventable visual disability. During Heightened awareness of this problem among the
the last 4 decades there have been reports from different ophthalmologists and medical microbiologists has
parts of the world about the increasing incidence of contributed to the increasing recognition of the disease.
this entity. Depending on the characteristics of the
population and the geographic areas, there is variation The aim of this study was to find out the epidemiology,
in the distribution of the causative organisms. clinical presentations and outcome of treatment for
mycotitic keratitis in a large teaching hospital
Some of the factors that have been held responsible subserving the northern districts of this state (Kerala).
for this increasing incidence of fungal keratitis include
the wide spread use of broad spectrum antibiotics and Inclusion Criteria
steroids, the frequent and sometimes prolonged use of
contact lenses and the growing number of corneal All the patients with corneal ulcers attending the
surgeries being performed. Steroid is a double-edged Ophthalmology out patient department of Kozhikode,
weapon that controls the inflammation but Medical College, during the period of the study were
increases the susceptibility of the individual to the subjected to KOH stain and fungal cultures of their
microorganisms. corneal scraping. Those patients who were found to be
KOH positive or fungal culture positive or both were
In countries like India with primarily Agrarian taken up for the present study.
population, trauma is very common. In addition,
favorable tropical environment and unhygienic Exclusion Criteria
practices like putting herbal medicines in the eyes make
mycotic keratitis very common. Mycotic keratitis is a Ulcers with picture of viral origin, ulcers from which
scrapings cannot be taken due to perforation and
Dept. Of Ophthalmology, Medical College, Calicut uncooperative children were excluded from the study.

June 2008 K.V. Raju et al. - Fungal Corneal Ulcer 149

Materials and Methods Incidence in relation to occupation

A detailed history regarding the disease with special In the present study agricultural workers showed the
reference to the mode of injury, patient’s age, sex and highest incidence (40 %) followed by manual labourers
occupation were noted. Any history of ocular or (33 %). In the study by Bharathi et al 64.75 % fungal
systemic illness was noted. All patients were subjected corneal ulcer was seen in farmers.
to detailed clinical examination. The scrapings were
sent for KOH mount to detect fungal filaments. Fungal Incidence of predisposing factors
culture was done in Saboraud’s dextrose agar medium
and bacterial culture in blood agar. Subcultures were Of the 30 cases 22 patients (72.6 %) had history of
done in necessary cases with the assistance from the trauma. In the study by Srinivasan M et al in 1997
Department of Microbiology. After the material was sent trauma as a predisposing factor was seen in 65.4 %.
to microbiology, patients were put on broad spectrum
antibiotics and if there was a history suggestive of fungal Ocular trauma, most commonly was with leaf and thorn
infection Natamycin was added. If the KOH mount was 8 (26.7 %) followed by injury with stick 4 cases
positive for fungus, patients were put on topical (13.3 %), with coconut shell 1 case (3.3 %). 43.3 %
Natamycin 5 % at two hourly interval. If the patients cases injury was with vegetable matter. This tallies with
were found to be positive for culture, Tab.Ketoconazole the 52.8 % reported by Srinivasan M et al.
200 mg twice daily was started for 2-3 weeks. The
response to treatment was assessed daily by slit lamp Systemic predisposing factors were present in 42.9 %.
examination till the ulcer started to heal and the Among this the commonest was diabetes mellitus
patients showed symptomatic improvement. The 5(16.7 %) 3 patients were anaemic (10 %) 3 were
patients were then followed up weekly for a period of alcoholic (10 %). Tuberculosis and leprosy 1 case each.
two months and in some cases for extended periods. Ocular predisposing factors were present in 16.7 % in
this study.

Results and Discussions Incidence of previous treatment

Out of the 100 cases, the incidence of mycotic keratitis Of the 30 cases, only 8 had history of previous
was 30 % in this study. treatment. Twenty-two patients had no previous
treatment. 16.7 % were on antibiotics 6.7 % were on
Age Distribution native medicines and one patient was on steroids. In
the study by Choudhary et al topical corticosteroids
The agewise distribution of keratitis showed that the had been prescribed to 21 % of patients at the onset of
incidence is highest in 31- 40 years age group (30 %) symptoms.
which closely followed by 41-50 years age group. This
could be due to the fact that they are physically active Clinical features
and working out doors and prone to injury. Our study
tallies with the peak age group detected by Choudhary Of the 30 cases, right eye was involved in 19 cases and
et al (1999-2001) (37 %). LE in 11 cases. There was not a single bilateral case.
Almost all the ulcers had textbook description of dull,
Sex incidence gray-raised surface. Some had a viral like appearance
to start with. In the study by Bharathi et al 75.43 %
The present study showed a male preponderance with had dry thick and raised corneal surfaces. 20 % of
23 males (77 %) and 7(23 %) females. This could be patients presented with an ulcer size of more than
due to their outdoor work and increased chance of 5 mm. 70 % had a size of 2-5 mm and 10 % of less
ocular trauma. than 2 mm. Majority of patients had an ulcer depth of
¼ - ½ (43.3 %) 9 patients had hypopyon (29.7 %).
The study by Bharathi et al showed male preponderance In our study most of the hypopyon were 2 mm or less
of 65.05 % and Choudhary et al it was 68 %.

150 Kerala Journal of Ophthalmology Vol. XX, No. 2

at the time of presentation. Satellite lesions were seen Table 1. Organisms isolated Percentage
in 10 %. Dendritic pattern was seen in 3.3 %. Corneal
abscess was seen in 1 case. (3.3 %). In one case there Organisms 42.9
was corneal perforation (3.3 %). 19.8
Fusarium
Fungal incidence Aspergillus 6.66
Curvularia 3.33
Of the 30 cases studied the most common fungi isolated Pencillium
was fusarium species in 13 cases (42.9 %). This was
followed by Aspergillus species 6 cases (19.8 %). Treatment response
(table 1). This is comparable to the study by
Sreenivasan M et al (Fusarium 47.1 % and Aspergillus Natamycin and ketoconazole were the drugs used in
16.1 %). In this study 10 % KOH mount was positive this study. Small superficial ulcers showed good
in 27 cases (90 %). response. Only one case of fungal corneal ulcer
perforated. This case had corneal abscess, hypopyon
and perforated and had previous treatment with
steroids.

Fig. 1. High power view of Aspergillus Conclusion

Prevalence was found to be more common in male rural
dwelling agriculturists. Fusarium is the commonest
species identified. 10 % KOH mount is a very sensitive,
simple and rapid test in detecting fungal filaments.
5 % Natamycin is the drug of choice for most of the
filamentous fungi. Small superficial ulcers, early
diagnosis and appropriate treatment showed faster
healing.

Fig. 2. High power view of Penicillium References
Fig. 3. High Power View of Curvularia
1. Text book of Grayson’s Diseases of the Cornea, 4th Edn.
By Robert C.Arffa p.21-252; 25-276.

2. Sundaram BM, Badrinath S, Subramanian S. ‘Studies
on mycotic keratitis’. Mycoses 1989; Nov.32[11]:
568-72.

3. Srinivasan M, Gonzales CA, George C, Cevallos V.
Aravind Eye Hospital, Madurai. S. India. Epidemiology
and aetiological diagnosis of corneal ulceration in
Madurai. S. India. BJO, 1997; Nov. 81[11]: 965-71.

4. Srinivasan M. Keratomycosis in S. India. The
transactions of the World Congress on the Cornea 111.
Edited by Dwight Cannangh, 1984.

5. Gopinathan V et al. The epidemiological feature and
laboratory results of fungal keratitis, a 10yr review at a
referral eye care centre in S. India, Cornea, 2002; 21:
555-559.

6. Bharathi MJ, Ramakrishnan et al. Epidemiological
characteristics and lab diagnosis of fungal keratitis. IJO
2003; 51: 315-321.

7. Srinivas M et al. Aravind Eye Hospital. Infective
Keratitis. A challenge to Indian Ophthalmologists, IJO
2007; Vol. 55, Issue 1.

June 2008 K.V. Raju et al. - Fungal Corneal Ulcer 151

ORIGINAL
ARTICLE

Primary Vitrectomy for Pseudophakic
Rhegmatogenous Retinal Detachment
Uncomplicated by Proliferative
Vitreoretinopathy (PVR)

Dr. Meena Chakrabarti MS DO DNB, Dr. Valsa Stephen MS DO DNB, Dr. Sonia Rani John DNB,
Dr. Arup Chakrabarti MS DO

Introduction in 1960. The clinical features of retinal detachment after
cataract surgery 3, 4 are different from those in phakic
The primary aim of a retinal reattachment procedure eyes: (1) the responsible tears are small located
is to close all responsible retinal breaks and relieve any anteriorly at the insertion of vitreous base. (2) the
vitreoretinal traction. This can be achieved by an detachments are more extensive and macular
external scleral buckle, placed after localization and involvement is very common. (3) signs of PVR are
retinopexy of the break, to mechanically close it. The common. (4) the incidence of ‘no break found’ is more
same effect can also be achieved by pars plana common as there is difficulty in visualizing the ora due
vitrectomy. to the glare and reflexes produced by the IOL, the
presence of posterior capsular opacification as well as
Since its introduction in 1970 by Dr.Robert Machemer, poor pupillary dilatation. Significant predispositions
pars plana vitrectomy has played an important role in include intraoperative posterior capsular rent with
the management of complicated retinal detachments. vitreous disturbances, Yag laser capsulotomy, myopia
To date several indications have been identified: with axial length > 25 mm, h/o retinal detachment in
the fellow eye or a family history of retinal
(1) presence of various grades of proliferative detachment .5,6,7,8,9
vitreoretinopathy (PVR) (2) Giant retinal tear, (3)
complex arrangement of retinal breaks such as large The basic surgical principles of scleral buckling and
posterior tears, (4) macular holes (5) multiple breaks vitrectomy applies to pseudophakic retinal detachment
at different levels (6) presence of media opacities. (RD) also. However they present certain unique
However the precise role of vitrectomy in the difficulties during surgery. The greatest problems 10, 11
management of uncomplicated rhegmatogenous retinal are
detachment is still controversial.
(1) Difficult visualization of periphery and hence a
Pseudophakic Retinal Detachments 1, 2 have presented higher incidence of “no break found” necessitating
unique and difficult problems to vitreoretinal surgeons larger buckle placement, more extensive cryopexy
since it was initially described by Tasman and Annesely both of which stimulates a greater degree of post
operative inflammation and PVR formation.
Chakrabarti Eye Care Centre, Kochulloor, Trivandrum - 695 011
Email: [email protected]

152 Kerala Journal of Ophthalmology Vol. XX, No. 2

(2) The location of the IOL presents problem during The surgical procedure included a conventional pars
scleral buckling and vitrectomy. Anterior plana vitrectomy. Any vitreous traction present around
movement of the anterior chamber intraocular the retinal tear was relieved. Indirect ophthalmoscopy
lens (caused by hypotony) during subretinal fluid was then performed to rule out any other preexisting
drainage or during fluid - air exchange can or iatrogenic retinal tears. Fluid-air exchange with
damage the cornea or press against the angle simultaneous endodrainage was performed either
causing hyphema intraoperatively. through the retinal tear if it was posterior or through a
drainage retinotomy. Once pneumohydraulic
Presence of PC rent causes problems for visualization reattachment was achieved, retinopexy was performed
after fluid air exchange due to moisture condensation either by trans- scleral cryopexy or LIO laser barrage.
on the IOL intraoperatively. So also silicone IOL-silicone Long acting tamponade was achieved by a non
oil interaction leaves behind a firmly adherent layer of expansile mixture of air and C3 F8 gas. The patients
silicone oil, impairing intraoperative visualization as were advised to maintain a face down position for
well as the postoperative visual recovery. atleast 12 hours – 16 hours daily for 3 weeks
postoperatively. The duration of hospital stay was 3
Previous reports on the management of retinal days. The patients were monitored for any
detachment has shown a poor rate of anatomic success postoperative reaction and rise of intraocular pressure.
in the presence of trans-sclerally sutured posterior
chamber intraocular lens and have speculated the Follow up examination was performed every month for
existence of certain risk factors which were associated the first 3 months and then at 2 monthly intervals for
with poor prognosis for surgical repair. These includes the next 6 months. The duration of follow up varied
presence of vitreous in front of the intraocular lens, from 6 months- 48 months.
poor pupillary dilatation, difficulty in visualization
during fluid- air exchange due to air gushing into Results
anterior chamber and persistent tractional forces at the
vitreous base due to the haptic of the IOL or the fixation The patients were of the age group ranging from 7 years
sutures. to 54 years (Mean- 37 years). The male:female ratio
was 2:1. All patients had a detachment of less than a
In this paper we analyze the results of primary month due to superior breaks and the macula was off
vitrectomy in 50 eyes with uncomplicated pseudophakic in all cases. The preoperative fundus findings were
rhegmatogenous retinal detachment. tabulated in Table 1.

Materials and Methods Table 1: Preoperative Fundus Findings & Relevant Clinical
Features
We performed a prospective study on the efficacy of
primary pars plana vitrectomy in the management of 1. Pseudophakia : (PCIOL: 36, AC IOL: 11,
uncomplicated pseudophakic rhegmatogenous retinal
detachment in 50 consecutive patients attending our SF IOL:3)
tertiary care referral centre between 2004 and 2007.
2. Hypotony : 15 eyes (30 %)
The patient’s age ranged from 7 yrs – 64 yrs, the M: F
ratio was 2:1. All patients had a retinal detachment 3. AS reaction (Flare and Cells) : 10 eyes (20 %)
less than a month old and the macula was off in all the
cases. There was no evidence of PVR. All patients were 4. Poor pupillary dilatation : 12 eyes (24 %)
pseuodophakic and included 36 eyes with posterior
chamber intraocular lens implants, 11 eyes with 5. IOL Malposition : 4 eyes (8 %)
anterior chamber intraocular lens and 3 eyes with
transclerally sutured posterior chamber intraocular lens 6. PCO : 9 eyes (18 %)
implants.
7. PC Rent : 6 eyes (12 %)

8. Vitreous in AC : 3 eyes (6 %)

9. Macula off : 50 eyes (100 %)

10. No break found : 9 eyes (18 %)

11. Choroidal detachment : 9 eyes (18%)

12. Vitreous haze : 5 eyes (10 %)

13. Total RD : 14 eyes (28 %)

14. PVR C Grade : 5 eyes (10 %)

15. Vitreous haemorrhage : 3 eyes (6 %)

June 2008 M. Chakrabarti et al. - PPV in Pseudophakic RD 153

The study population included 36 eyes with PC IOL Development of corneal odema intraoperatively and
implants (72 %); 11 eyes with AC IOL implants pupillary miosis were the two major intraoperative
(22 %); and 3 eyes with trans-sclerally sutured PC IOL difficulties experienced during surgery. Epithelial
(6 %) implants. Preoperative hypotony (30 %); debridement was necessary in 24 % of eyes to clear
significant anterior chamber reaction (20 %); vitreous the visual axis for adequate visualization during
in anterior chamber (6 %); poor pupillary dilatation surgery.Pupillary miosis intraoperatively was countered
(24 %); malpositioned IOLs (8 %), PCO (18 %) and using iris retractors or by adding adrenalin to the
presence of vitreous haze (10 %) made intraoperative infusion fluid in 28 % of cases. Intraoperative hyphema
visualization difficult. Preoperative topical and systemic was caused by fluctuations in the intraocular pressure
steroid administration to control the inflammation and intraoperatively in 4 %. Injection of viscoelastic into
combat hypotony was successful in achieving a quiet the anterior chamber cleared the pupillary area.
eye in 20 % cases. Use of flexible iris retractors, Shallowing of the anterior chamber after fluid- air
sphincterotomies, posterior capsulotomy and repositioning exchange was observed in 8 % of eyes. In these 4
of the IOL into the bag or sulcus was performed intra patients, the chamber reformed spontaneously when
operatively to achieve adequate pupillary space for prone position was maintained postoperatively. Minimal
visualization of fundus periphery and to perform a displacement of the PC IOL which occurred
thorough base excision. 18 % of patients had choroidal intraoperatively in one patient was managed
detachments associated with hypotony and total retinal conservatively. Collection of blood within the capsular
detachment. Choroidal detachments were drained bag intraoperatively impaired visualization in 2 % of
before placement of infusion canula. A break eyes necessitating central capsulectomy for drainage.
responsible for the detachments could not be identified Bubbling of air into the anterior chamber during fluid
in 18 % of patients either pre or intraoperatively. air exchange occurred in all the 3 patients with sclerally
sutured PC IOLs impairing visualization. Intraoperative
Table 2. Intraoperative problems and complications moisture condensation in 12% was cleared by flute
needle. Moisture condensation on the posterior surface
Sl. Introperative Incidence Management of the IOL in 6 eyes (12 %) with pre-existing posterior
No Problems ( %) capsular rent was managed by gently sweeping the
posterior surface of the IOL with a soft tipped aspiration
1 Corneal Odema 12 eyes Debridement needle.

(24 %) The patients were followed up for 12 months. The
anatomic reattachment rate was 96% with a single
2. Intraoperative 2 eyes Viscoelastic inj procedure. In 2 eyes (4 %) recurrent retinal detachment
with advanced proliferative vitreoretinopathy and gross
hyphema (4%) into AC hypotony necessitated revitrectomy with silicone oil
tamponade.80 % of the patients achieved a visual acuity
3. Pupillary Miosis 14 eyes Iris Retractors, > 6/12 to 6/60. Poor visual recovery in 10 eyes (20
%) was attributed to (1) Epiretinal membrane
(28 %) adding Adrenalin formation 2 eyes (4 %); (2) Macular hole 2 % (4)
persistent cystoid macular odema 4 % (5) persistence
to infusion fluid of SRF in macular area detected by OCT in 10 %.

4. Displacement 2 eyes Conservative (1); We analyzed factors which predicted poor visual
recovery and redetachment. These included
of IOL (4 %) Repositioning (1) preoperative anterior chamber reaction, choroidal
detachment, older patients and longer duration of
5. Shallowing 4eyes Reformed detachment. There was no significant difference in the
reattachment rates with the different IOL types.
of AC (8 %) spontaneously with

prone positioning

6. Blood in 1 eye Capsulotomy

Capsular bag (2%) and drainage

7. Air in AC during 3 eyes

fluid air exchange. (6%)

8. Moisture condensat- 6 eyes Cleared with flute

ion on IOL (12%) needle

9. Difficulty in base 4 eyes Scleral depression

excision (8 %) assisted base

excision

154 Kerala Journal of Ophthalmology Vol. XX, No. 2

Discussion 7. Interaction between silicone oil and silicone
foldable IOL in the presence of PC rent causes
The basic surgical principles of scleral buckling and pars impaired visualization for surgery.
plana vitrectomy continues to apply to pseudophakic
retinal detachment, but there are certain problems 8. In our series of 3 cases of pseudophakic retinal
unique to pseudophakia. The greatest problem in detachment associated with trans-sclerally sutured
repairing a pseudophakic retinal detachment is the posterior IOLs, the clinical features and problems
difficulty in visualizing the peripheral retina. Retinal faced during surgery did not differ from eyes with
breaks cannot be found in as many as 20 % of patients conventional posterior chamber intraocular lenses.
due to small miotic pupils, difficulty in viewing through All patients had well dilated pupils. Absence of
edge of IOL, perilenticular membranes and posterior posterior capsular opacification and perilenticular
capsular opacification. cocoon membranes made visualization of retinal
periphery easy. Intraoperative problems such as
Visualization tends to be more difficult in iris fixated IOL dislocation, significant IOL decentration,
and AC IOLs. Because of uncertain visualization, there vitreous haemorrahage, hyphema and
may be a tendency towards greater use of cryotherapy pseudophakic corneal touch were not experienced
which is associated with increased inflammation and while managing these patients. The only
postoperative PVR. The location of the IOL, whether in intraoperative problem was difficulty in
anterior chamber, iris plane or in the posterior chamber visualization during fluid - air exchange as air
presents problems during scleral buckling and gushed into the anterior chamber. Similar
vitrectomy. problems are experienced in eyes with anterior
chamber IOLs or posterior chamber IOLs with
1. An anterior chamber lens, during scleral posterior capsular rent or following YAG
depression may be forced against the angle capsulotomy.
causing bleeding.
IOL explantation for intraoperative decentration or
2. Mobility of iris fixated lenses can cause corneal dislocation of the IOL or to permit visualization for
damage from anterior displacement at time of vitrectomy was not necessary in any patient. Adequate
subretinal fluid drainage when the eye is anterior vitreous base dissection was possible in all the
hypotonous. eyes which permitted intraoperative retinal flattening.

3. An intravitreal gas bubble will also displace an An anatomic success rate of 93.0% (88.8-93%) for
iris fixated lens anteriorly. Prior injection of air/ pseudophakic retinal detachment cases have been
healon into the anterior chamber will prevent this. reported by Schepens in 1991. The PC IOL group has a
significantly greater prevalence of good postoperative
4. Postoperative pupillary block and choroidal visual acuity compared to AC IOL groups which have
detachment also causes anterior displacement of the worst visual prognosis. The cause of poor visual
IOL against cornea requiring immediate recovery after retinal detachment repair in patients with
repositioning to prevent irreparable corneal AC IOL is attributed to the increased occurrence of
damage. postoperative corneal oedema. Patients having an AC
IOL implant have a higher degree of occurrence of break
5. Dislocation of lens into vitreous can occur with down of BAB (blood-aqueous barrier) before treatment
posterior chamber intraocular lenses. Posterior of retinal detachment. Therefore the persistent corneal
chamber intraocular lenses pose the fewest dysfunction in the presence of an AC IOL may trigger
difficulties during scleral buckling and vitreous the postoperative corneal oedema and explain the
surgery. poorest visual acuity outcomes.

6. Intraoperative moisture condensation on the The statistically significant poor prognostic indicators
posterior surface of IOL during fluid- air exchange for reattachment are.
may impair visualization of posterior segment in
eyes with preexisting posterior capsular rents.

June 2008 M. Chakrabarti et al. - PPV in Pseudophakic RD 155

1. Presence of AC IOL (2) Eyes with AC reaction (3) FAE allows pneumohydraulic retinal reattachment 15,
Presence of macula off RD (4) Preoperative PVR (5) 16. Vitreous opacities are removed at the time of
Older age etc vitrectomy and postoperative mobility is less. It should
also be recognized that there are potentially hazardous
The reasons for failure include the development of complications of this procedure like progression of
proliferative vitreoretinopathy, failure to close an nuclear sclerotic cataract, glaucoma, iatrogenic tears
existing break or development of a new break. Although and detachment and vitreous haemorrhage, etc 17, 18.
the anatomic reattachment rate is comparable to that
in phakic eyes, the visual results are not so good. The Primary pars plana vitrectomy offers an alternative to
postoperative visual recovery is worst with AC lenses scleral buckling procedures in the management of
due to the presence of corneal decompensation and selected cases of primary rhegmatogenous retinal
higher incidence of cystoid macular odema. The other detachment. A larger series with longer follow up is
causes of poor visual recovery after successful anatomic needed before the efficacy of this procedure is
reattachment are macular degeneration, cystoid established.
macular edema, epimacular membrane proliferation,
macular pucker and photoreceptor dysfunction. References

Pars plana vitrectomy has become accepted as the 1. Norman S Jaffe, MD Hentry M, Clayman MD Mark Jaffe,
treatment of choice for certain complex retinal MD Retinal Detachment in Myopic eyes after
detachments. The commonest indications are difficult intracapsular cataract surgery Am. J Ophthalmol 97:
breaks and PVR. In simple retinal detachments, external 48-52, 1984.
scleral buckling procedures are still preferred. The role
of primary vitrectomy in the management of these cases 2. Craig M Greven, MD, Reginald J Sanders, MD Gary
is still controversial. Brown, MD William H Annesley, MD Lov Ksarin MD,
William Tasman, MD Timothi M Morgan, Ph.D,
Scleral buckling procedures can be complicated by a Pseudophakic Retinal Detachment Ophthalmology,
variety of intraoperative and postoperative 99:257-262, Feb .1992.
complications which can impair the final visual
result 12. A combination of factors may result in intrusion, 3. Akitoshi Yoshida, MD, Hironobu Ogaswara, MD Alex E
extrusion or infection of the scleral buckle 13, 14. Mobility Jalkh, MD, Reginald J Senders MD, J Wallce McMeel,
problems may be induced by the presence of bulky MDD Charles Schpens, MD Retinal detachment after
scleral buckle or due to disinsertion or rupture of the cataract surgery – Surgical Results Ophthalmology,
extraocular muscle during surgery. External drainage 99:460-465, March 1992.
of SRF may result in subretinal haemorrhage, retinal
incarceration or a retinal break. Encircling elements 4. Kristian Yoshida, MD Chiyuki Kobayashi, MD.
may reduce the blood flow as shown by colour doppler Epidemiology of aphakic retinal detachment following
studies and results in anterior segment ischaemia. intracapsular cataract extraction: A follow up study with
Refractive changes are a rule after scleral buckling an analysis of risk factors. J. Cataract Refract Surg:
procedure and may be especially problematic if a 14:303-308, May 1988
significant degree of anisometropia has been induced
in a previously emmetropic eye. Buckling elements may 5. Roger F Steinert MD, Carmen A Puliofito MD,Sanjiv
result in distortion of macula and reduction of macular Kumar MD, Scott D Dudak, MD and Samir Patel MD
function. Further buckling procedures may be Cystoid macular edema, Retinal Detachment and
associated with postoperative CME which may account Glaucoma after Nd: YAG Laser posterior capsulotomy
for delayed return of vision. Am.J. Ophthalmol. 112: 373-380 Ocober 1991.

Vitrectomy 12, 13, 14 offers certain advantages over scleral 6. Akitoshi Yoshida, MD, Hironobu Ogaswara, MD Alex E
buckling in that it affords a direct approach to vitreous Jalkh, MD, Reginald J .Senders MD, J Wallce McMeel,
traction. Internal drainage of SRF with simultaneous MD Charles Schepens, MD Retinal Detachment after
cataract surgery- predisposing factors Ophthalmology,
99: 453 – 459, March 1992.

7. Patrick Coonan MD, Wayne E Fung MD, Robert G
Webster MD, Arthur W Allen MD, Richard L Abbott MD
The incidence of retinal detachment following
extracapsular cataract extraction Ophthalmology,
92:1096- 1101, August 1985.

8. Lynda Rickman Barger, Craig W Florine, MD Rhondi S
Larson MD, Richard L Lindstrorm MD. Retinal detachment
after Neodymium Yag Laser posterior capsulotomy
Am.J.Ophthalmol 107 : 531- 536, May 1989.

156 Kerala Journal of Ophthalmology Vol. XX, No. 2

9. Verinder S Nirankari MD, Richard D Richards MD 14. Kato Chiaki et al Outcome of primary vitrectomy for
Complications associated with the use of the pseudophakie retinal detachment Jpn.J. Ophthalmol
Neodymium: YAG Laser Ophthalmology, 92:1371- 75, 2001;55(6) 1225-1228
October, 1985
15. D.Singh,Y Sharma,N.Pal Scleral buckling versus primary
10. Henry M Clayman, MD Norman S JaffeMD, David S Vitrectomy Ophthalmol Vol 113(7) 1246-1247
Light MD, Mark S Jaffe MD and Janet C Cassady MS
Intraocular lenses, axial length and retinal detachment 16. Campo RV,SipperlyJo,Sneed SR et al Parsplana
Am.J Ophthalmol, 92:778-780, 1981 vitrectomy without scleral buckle for pseudophakic
retinal detachment Ophthalmology 1999,106 :
11. Michael- Ulrich Dardenna, George- Johannes Gethen, 1811-1815
Kyros Kokkar, Omid Kermani Retrospective study of
retinal detachment following Nd YAG laser posterior 17. Le Rouic JF,Behar-Cohen et al Vitrectomy without
capsulotomy J.Ctaract Ref. Surgery, 15 : 676-680, Scleral buckle versus ab-externo approach for
Niv.1989. pseudophakie retinal detachment J.Fr.Ophthalmol
2002;24;240-245
12 K.U. Bartz-Schmidt,B Kirchhof Primary Vitrectomy for
pseudophkic retinal detachment Br.J. Ophthamal .1996 18. Pournaras CJ,Kapetaneas.AD Primary Vitrectomy for
April :80(4); 346-349 pseudophakie retinal detachment –a prospective non-
randomised study Eur.J.Ophthalmol 2003; 13:298-306
13. Dubey Aravind,Dubey Binu. Primary 25gauge
Transconjunctival Sutureless Vitrectomy in 19. Shwu Jiuan Sheu, Tzong- Dean Wu et al Is trans- sclerally
pseudophakie retinal detachment-letter to Editor sutured intraocular lens a poor peognostic factor for
Ind.J.Ophthalmol:2008,56(3) 256-57 management rhematogenous retinal detachment?
Annals of Ophthalmol 1996; 28(4):294-248.

HUMOUR IN OPHTHALMOLOGY

Political Correctness (Or Euphemism?)

RRV

Recently I happened to come across a slim volume treatment, surgical or medical. The aqueous
titled ‘Politically Correct Fairy Tales’. The first percolation through the artificial intralamellar
fairy tale was named “The Melanotically pathway is suboptimal, you can say about a failed
Impoverished Person of Royal Descent and Seven bleb. These ‘suboptimal’ or ‘deficiently optimal’
Vertically Challenged People”. Lost, aren’t you? It results can be there in any treatment. The more
was the story of Snow White and the Seven obfuscating the word/ phrase is, the better. The
Dwarfs. same is true for prognostication too. You can be
fully honest, yet incomprehensible. And the patient/
The word ‘political correctness’ will not be found by-standers will be impressed into the bargain.
in any dictionary printed before the nineties. But
once it came into vogue, it is there with a Another advantage is that all of us who called
vengeance. Nowadays anything one say may be ourselves as ‘General Ophthalmologists’ can now
interpreted on its political correctness. use the much more impressive sounding
‘Comprehensive Ophthalmologist’.
As we are all aware there are no blind people any
more. They are all ‘visually handicapped’ or still Some time back, in a hospital attached to a Central
better, ‘visually challenged’. Even the word Government Institution, one of those pompous
handicapped is considered improper. ‘Differently Central Secretaries came for a visit. The
abled’ is the current correct term, it seems. Ophthalmologist was conducting the weekly
Sometimes we tend to forget and blurt out the medical board when a visit was paid to the OPD.
outmoded word and cause wrinkles to pop up on “Ah…m..m. You check the fields of all the crane
the foreheads of discerning listeners. operators, don’t you?” asked the Secretariat
Mandarin. “Of course sir, we do digital perimetry”.
Even though it has got disadvantages for people The answer satisfied him, especially the ‘digital’
over forty (who are used to speaking or writing in part. I am sure that he did not know that ‘digital’
a straight forward manner), it has some can allude to your fingers too. Another example
advantages too. This comes in handy while of political correctness saving the day!
explaining the (unfavourable) outcomes of your

June 2008 S. Vishwanath et al. - Study of Viral Conjunctivitis 157

ORIGINAL
ARTICLE

Clinical and Virological Study of
Conjunctivitis during the Epidemic in
Calicut October - December 2006

Dr. Sheeja Viswanath MS, Dr. K S Chandrakanth DO DNB, Prof. (Dr). P. Vijayan MS, Prof. (Dr). Venkitachalam MS
Dr. Nirupama Balaji DO DNB, Dr. Tresa Mathew MS, Dr. Ramakrishnan MS

Abstract

9 % of blindness in India is due to corneal diseases. With effective antimicrobials, and improved
nutrition infective keratitis of non-viral origin and vitamin deficiency diseases are on the line
of decline whereas viral keratitis tends to become more prevalent. Our aim was to analyse
the clinical and virological aspects and to evaluate the efficacy of topical Acyclovir in preventing
the development of keratitis. 55 patients were selected for virus isolation using human amnion
and human lung cancer cells (AV- 3 and A549). Adenovirus type 8 was isolated from 40 %.
All the cases including those having keratitis responded well with topical regimen. Our study
highlighted the need for early and prompt institution of topical Acyclovir in preventing the
development corneal complications and subsequent blindness.

Introduction A variety of viruses can be responsible for conjunctival
infection. Adenovirus is the most common and is highly
According to WHO, corneal diseases are the 2nd most contagious during the first 2 weeks of infection. It has
common cause of blindness in the world today 1. A the tendency to occur in epidemics. Ocular adenoviral
recent national survey conducted by the Govt. of India infections are characterized by highly distressing local
(1991-2001) estimated that the corneal lesions are symptoms. It can occur with corneal involvement within
responsible for 9 % of all blindness in our country 2. 4-5 days after the onset of symptoms. The corneal
lesions range from diffuse fine superficial punctate
Majority of the causes of blinding corneal pathology keratitis to epithelial defects and finally to sub epithelial
are avoidable or preventable or treatable. Previously nummular opacities which can last long, even for
the corneal blindness was predominantly due to years 3. These nummular opacities can impair visual
malnutrition, bacterial and fungal ulcers, followed by function significantly and can cause glare. Currently
trauma. In the present era with improved nutrition and no specific antiviral therapy is available to shorten the
due to the advent of effective antimicrobials infective course of infection or to improve distressful clinical
keratitis of non viral origin are on the decline whereas symptom, to stop viral replication and to avoid the
viral keratitis has become more prevalent. development of corneal opacities 3. Research is ongoing
for topical agents that have anti viral activity. One drug
Malabar Eye Hospital, Calicut

158 Kerala Journal of Ophthalmology Vol. XX, No. 2

that holds promise in this area is cidofovir 4. In 1996 treated with antibiotic drops alone; group B1 (severe)
Gordon-et al 5 first reported the clinical efficacy and with antibiotic-Acyclovir combination and group B2
safety of cidofovir in the treatment of the patient with with Acyclovir steroid antibiotic combination to the
proven acute kerato conjunctivitis 5. To the best of our involved eye (the regime is given in table number II).
knowledge no study was reported regarding the efficacy All the patients treated outside were considered as
of topical Acyclovir in the management of acute phase severe and started on Type 3 regime.
of viral conjunctivitis.
Duration of treatment was for 21 days. Patients were
Aim of Study followed up on 3rd, 7th, 14th, 21st and 30th day if required.
At each visit, follicular reaction, conjunctival congestion
The purpose of our study was to analyze the clinical and and corneal involvement were documented.
virological aspects and also to evaluate the efficacy of
topical 3 % Acyclovir eye ointment in the treatment of Observations and Discussion
acute phase of viral conjunctivitis and also in the prevention
of development of corneal opacities in the late phase. Fig. 1. Age Incidence

Materials and Methods Total no: of pts.:55

A total of 55 patients with clinical features of acute Maximum Age Incidence was between 20-40 yrs
viral conjunctivitis were studied at Malabar Eye Hospital (40 %) followed by 40-60 yrs (27 %). Similar
during the Epidemic in October -December 2006. observations were made by Norn M.S 6 (1974) who
found that 59 % cases were adults.
The diagnosis was made by clinical examination and
confirmed by viral culture using human aminon cells Fig. 2. Sex Incidence
and human lung cancer cells (AV-3 and A549). For virus
isolation, conjuctival swabs taken from lower fornix (47.28 %)
were sent to Ooty and the results were analyzed. Only
the acute cases of suspected viral conjunctivitis during (52.72 %)
the epidemic were included in the study. Conjunctival
hyperemia petechial and sub conjunctival hemorrhages, Total no: of pts.:55
involvement of pre auricular lymphnode, coryza, the
infiltration of cornea and the response to treatment Out of 55 patients 29(52.72 %) were males and
were evaluated in all patients. The efficacy of treatment 26(47.28 %) were females. Gunderson 7 (1938) in his
was studied in 2 main groups. study reported that both sexes were equally affected.

First group included patients coming after treatment
elsewhere with antibiotic drops alone and without
much relief, 2nd group coming primarily to us with
typical signs and symptoms of viral conjunctivitis. The
patients seen primarily by us were treated in 3 groups
of 10 each. The division was based on the severity of
clinical features as mild or severe. Family members of
culture positive patients who developed mild symptoms
of conjunctivitis with minimal congestion, chemosis,
follicles and petechial hemorrhages in the upper tarsal
conjunctiva with or without involvement of pre
auricular lymphnode were considered as mild. The
remaining 20 cases with severe form of conjunctivitis
were randomly divided into 2 treatment groups of
10 each (B1 & B2). Patients in groupA (mild) were

June 2008 S. Vishwanath et al. - Study of Viral Conjunctivitis 159
Fig. 3. Laterality Fig. 5. Duration of Keratitis

(40 %)

(62 %)

Total no of pts : 55 Total no of pts with keratits:12

In 33(62 %) cases, the disease was unilateral and Maximum number of cases 60 % (33.pts) visited our
22(40 %) cases bilateral. Khuran. A.K. et al. 7 reported OPD on the first six days of illness and 40 % on 2nd
35 % bilaterality in 1984. and 3rd week after getting some treatment outside
(Table 1). None of the patients (30) (54.54 %) seen by
Table 1: Clinical Features No: of Percentage us had keratits during their initial visit. 12/25 (44 %)
Patients patients in the first group who did not apply Acyclovir
Symptoms 100 % in the beginning started developing corneal lesion from
55 100 % 5th day onwards (Diagram 6). Sen et al 9 (1973) in
Eye ache 55 100 % their study of 105 cases of viral kerato conjunctivitis
Foreign body sensation 55 noticed superficial punctate kertitis in all their cases
Watering and discharge 10 20 % from 4th day on wards. There was mild impairment of
Fever & Throat pain visual acuity (6/9) in 10 patients with corneal
24 43.63 % involvement.
SIGNS 55 100 %
Pre auricular lymphadenitis 55 100 % Table 2. Results of Virological Study: 13 samples
Conjunctival congestion 10 10.90 % Type 08
Conjunctival Follicles 35 63.63 % Virus Isolation 55 samples
Sub conjunctival hemorrhage 12 10.8 % Adeno virus Type 32 samples
Petechial hemorrhage 00 Total no of specimen’s collected 23 samples
Corneal involvment Investigated for virus isolation 40 %
Uveitis Contaminated
Isolation Rate
Eye ache, foreign body sensation, watering and discharge
were present in all cases. All patients had follicular type
of conjunctival congestion (Table 1), 10 patients (20
%) had fever and more often ocular symptoms started
2-3 days after the onset of coryza (Fig. 4).

Duration of Symptoms (Interval between the onset Viral culture was +ve in 40 % cases and was found to
of symptoms and initial visit) Fig 4. be Adenovirus type 8. Out of 55 patients the sample of
23 patients were contaminated probably due to delay
Total no : 55 in sending the sample.

Fig. 4. Pie Diagram showing the onsent of occular symptoms Type 8 Adenoviral conjunctivitis is a highly contagious
after onset of coryza disease. It is necessary to diagnose the disease on time
for its proper management and all necessary steps
should be taken to prevent transmission. According
to many authors the treatment for viral conjunctivitis
is only supportive. Other than Cidofovir which is
found to be effective against the Type 5 Andeno
viral conjunctivitis in rabbit model 12, no other antiviral
drug is found effective against other strains of
Adenovirus.

160 Kerala Journal of Ophthalmology Vol. XX, No. 2

Treatment Regimen responded well with topical regimen, the recovery was
found to be faster in group 2 B2. This might be due to
Table No: 3 the use of Acyclovir, which might be preventing the
virus multiplication in the early phase. The applied
Regimen Group of patients Combination of medicines steroids also play an important role by accelerating the
to whom the subjective improvement of clinical features by
treatment was suppressing the polymorphonuclear leukocyte
instituted migration and capillary permeability.

Type 1 Mild (A) Antibiotic drops QID alone In group 1, the patients who did not have keratitis, the
to the affected eye symptoms markedly improved within 4 days and the
clinical features completely resolved within 7 days, with
Type 2 (B1) Topical Acyclovir (3 % e/o the topical Acylovir antibiotic steroid combination. In
5 times daily)+antibiotic those patients who had Keratitis the corneal lesions
drops QID to the affected eye resolved completely without any sequalae within the
first 2 weeks of treatment. This might be because the
Type 3 B2 Topical Acyclovir (3% e/o) lesions were not deep enough to disrupt the Bowmans
with steroid antibiotic membrane to involve the stroma. The use of Acyclovir
drops to the affected eye along with the steroids might have prevented the
progression of the natural course of the disease and
In our study Acyclovir has demonstrated a significant accelerate the improvement of symptoms.
antiviral activity in the early as well as late phase of
Type 8 Adenoviral conjunctivitis. Moreover, the Conclusion
incidence of corneal infiltrate was found to be nil with
the early application of Acyclovir. The inferences from our study are:

Response to Treatment 1. Early institution of topical Acyclovir can shorten
the course of Adenoviral infection.
Group 1 (consists of 25 patients treated outside with
antibiotic drops alone.)- Started on type 3 regime. 2. The use of topical Acyclovir with steroids enhances
the efficacy of treatment.
Group 2 include 30 patients - Primarily treated here.
A1-10 Pts. with mild C F -Type I Regime 3. Topical Acyclovir prevents the development of
B 1–10 Pts. Treated- Type 2 Regime. corneal infiltration when applied in the very early
B2 –10 Pts severe-Type 3 Regime. phase of Type 8 Adenoviral conjunctivitis.

With the application of antibiotic drops alone, the 4. The administration of antibiotic drops alone may
patients in group 2 A responded well and recovered not be safe in all cases.
completely from all symptoms within one week. This
might be due to the high immune response of the
individual or due to the low virulence of the organism.
Even though all the patients in group 2 B1 and B2

Table 4

Clinical Features 3 DAYS 6th day 12th Day 21st Day

Gp1 Gp 2 Gp 1 Gp 2 Gp 1 Gp 2 Gp 1 Gp 2

A BC ABC A BC AB C

Eye ache 25 6 8 0 12 0 6 0 6 0 0 0 00 0 0
00 0 0
Fb sensation 25 8 7 0 12 0 4 0 6 0 0 0 00 0 0
00 0 0
Water discharge 25 8 4 2 12 0 0 0 2 0 0 0 00 0 0
00 0 0
CC 25 10 10 6 25 0 6 2 12 0 0 0 00 0 0

Follicles 25 10 4 25 0 3 2 12 0 0 0

10 4 6 4 6 0 2 0 0 0 00

Keratitis 12 0 0 0 12 0 0 0 12 0 0 0

June 2008 S. Vishwanath et al. - Study of Viral Conjunctivitis 161

5. Even in cases of Keratitis the administration of 1% cyclosporine. Arch Ophthalmol. 2001; 119:
topical Acyclovir with steroid prevents the 1487-1491.
escalation of lesions into the deeper layers of the
cornea there by reducing the chances of developing 5. Gordon Y .Naesens L, DeClercq E,et al.Treatment of
corneal opacities. adenoviral conjunctivitis with topical (letter). Cornea,
1996, 15: 546.
References
6. Norn, M.S., Acta Ophthalmol., 1970; 48:91
1. Global initiative for the elimination of avoidable
blindness. WHO: Geneva; 1997. (unpublished 7. Gunderson,T., Am. J. Ophthamol, 1938; 225.
document) WHO /PBL.97-61-Rev.1
8. Khurana AK, Gutain HR,Parmar IPS, IJO 1984; 32.
2. Govt. of India. National survey of blindness. 1999-2001.
Report 2002 9. Sen SC,Saha PL,Banerjee AR, Das AK.A study of 105
cases of Kerato conjunctivitis. Indian J Ophthalmol 1977
3. eMedicine – Keratoconjunctivitis, Epidemic: Article by /25/33/34611.
Ahmed Bawazeer etal.,updated: April 11, 2006 MBChB,
FRC. Page 1of 10 10. Bejj C, Cho M, Eastwood S, et al. improving the quality
of reporting of randomized control the CONSORT
4. Jost Hillenkamp E,et al, Topical treatment of acute statement. JAMA. 1996;276:637-639
adenoviral keratoconjunctivitis with 0.2 % cidofovir and
11. Gorden YJ, Romanowski E, Araullo – Cruz T, De Clercq
E. Pretreatment with topical 0.1% (S hydroxyl – 2 –
phosphonylmethoxypropyl) cytosine inhibits
adenovirus type 5 replication in the new rabbit ocular
model. Cornea. 1992;11:529-533

OPHTHALMIC HISTORY

Gerhard Rudolph Edmund Meyer- Schwickerath [1920-1992]

Prof. Padmaja Krishnan MS
(With lasers being the “in” thing in Ophthalmology today, here is the man who paved the way…..)

The power of sunlight to damage the retina was When the world war
known from ancient times.
broke out, he joined up as
“People may injure their bodily eyes by observing
and gazing on the sun during an eclipse, unless a paramedic, but was sent
they take the precaution of only looking at the
image reflected in the water or some similar back from the frontline
medium”
after he sustained a knee
-Socrates, quoted by Plato in ‘Phaedo’
injury. He was thus able to
Galileo injured an eye while looking at the sun with
his newly invented refracting telescope, as did the study Medicine,
father of photocoagulation, Gerhard Rudolf
Edmund Meyer-Schwickerath, while experimenting graduated in 1945, took
with the production of radiant energy.
up Ophthalmology and
Meyer-Schwickerath, the German ophthalmologist,
was born in July 1920 at Wuppertal-Elberfeld, completed his Fellowship
Germany. He left school in 1937 at the age of
17 and decided to become a doctor. This was from Munster, Hamburg. Gerd Meyer - Schwickerath
against the family tradition of studying law as he
did not fancy practising Law under the Nazi regime. In 1952, he moved to the University of Bonn and
in 1959 became Professor and Director of the
University Eye Department in Essen, where he
continued to work until his retirement in 1985.

Meyer-Schwickerath conceived the idea
of therapeutic photo-coagulation when he was just
25 years old while trying to develop a diathermy
machine to treat retinal detachment. He had been
seeing a lot of patients, including one of his
students, with macular burns from watching the

Comtrust Hospital, Calicut (Contd. on pg. 218)

162 Kerala Journal of Ophthalmology Vol. XX, No. 2

ORIGINAL
ARTICLE

ROP Screening: Analysis of Factors
Predictive of Poor Visual Outcome and
Neurodevelopment in Preterms

Dr. Valsa T Stephen 1 MS DO DNB, Dr. Meena Chakrabarti 1 MS DO DNB, Dr. Naveen Jain 2 MD, Dr. Radhika 2 DNB,
Dr. Sonia Rani John 1 DNB, Dr. Arup Chakrabarti 1 MS DO

Studies analyzing the morbidity and long term subtle deficits related to preterm birth only identified
neurological outcome in extremely low birth weight at a later age. Visual function deficits are not limited to
infants (ELBW= < 1000gms and GA ≥ 34 weeks ) have visual acuity but can affect contrast sensitivity, field of
shown that 20.6 % of the babies develop major vision and colour vision 3. Strabismus (17.8 %) has been
neurological sequlae. ROP affected 26.6 %, while reported to occur in children who survive the
14.8 % of the children developed intraventricular morbidities of preterm birth 3. Esotropia and
haemorrhage and 14.1 % developed periventricular pseudoexotropia due to macular ectopia related
leucomalacia 1. cicatricial retinopathy of prematurity has been
described 5. Logistic regression analysis showed an
Health professionals and parents of preterm infants fear increased risk of strabismus in children with cicatrical
the development of bronchopulmonary dysplasia and regressed retinopathy, refractive error, family history
retinopathy of prematurity because these neonatal of strabismus, poor neuro developmental outcome in
morbidities are risk factors for development of particular impaired locomotor skills and hand eye
neurosensory impairment, low psychomotor coordination 6. Cryotherapy for ROP can cause acute
development index scores on the Bayley scales of infant inflammation and necrosis of muscle fibers which
development II, and neurotic mental development 2. improves overtime and does not result in structural
Ultrasonographic signs of brain injury such as changes on long term followup. Therefore occurrence
periventricular and intraventricular haemorrhage, of strabismus in patients with ROP is considered to be
periventricular leucomalacia, ventriculomegaly also attributable to reasons other than injury to EOM 9.
increase the risks of mental and motor impairments.
Severe ROP is significantly associated with Ophthalmological followup of preterm infants showed
neurosensory developmental impairment in children. severe visual impairment in 2.5 %, pointing to the urgent
need to follow-up all preterm babies screened for ROP.
Preterm birth, perinatal morbidities, retinopathy of The rate of myopia was 33.3 % in babies with ROP compared
prematurity are all associated with neurological damage to 3.7 % in babies with no ROP 7. Studies have shown
and visual impairment. Visual impairment can range that eyes with spontaneously regressed subthreshold
from blindness due to ROP or cortical visual stage II ROP were associated with better normal
impairment, which can be identified at an early age, to outcomes and lesser myopia than the treated groups.10

1 Chakrabarti Eye Care Centre, Kochullor, Thiruvananthapuram-695 011, Kerala, There is a paucity of data from India on predictors
India. E-mail : [email protected], [email protected] of visual and neurological outcome in preterm babies
2 Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum

June 2008 Valsa Stephen et al. - ROP Screening 163

< 33 weeks gestation. The aim of this study is to analyse fundus did not reveal any evidence of ROP were
the various risk factors that act as predictors of poor screened every 2 weeks, while those showing features
visual and neurological outcome in very preterm babies of ROP were screened weekly for any progression of
and to provide anticipatory guidelines to the parents. disease. Babies with prethreshold ROP were screened
This study also highlights the need for long term daily. The end point of screening was when the baby
followup in extremely preterm babies who survive the achieved a post-conceptional age of 45 weeks or normal
perinatal morbidities associated with preterm birth and intraretinal vascularisation was observed. Babies with
tries to define a model for developing a regional data threshold ROP underwent cryo or laser ablation of
base. peripheral retina according to the cryo ROP study
guidelines 12 within 48 hours of diagnosis and were
Materials and Methods followed up daily for a week and monthly thereafter
for 1 year. After discharge from the NICU, all the babies
This study was designed as a prospective were reviewed monthly by performing indirect
nonrandomized screening and observational trial with ophthalmoscopy and their refraction was assessed after
active intervention in the management of ROP as atropinisation at 6 months after birth. Assessment for
and when required. The study population included 130 ocular motility disorders and binocular visual function
in-born and out-born premature babies <33 weeks was carried out at age of 9 months or earlier if the
admitted at the tertiary care NICU of a multispeciality parents complained of noticing squinting in the child.
hospital from May 2004 to May 2007 . The birth weight, Corrective spectacle for refractive error and surgery for
gestational age, multiple oxygen exposure, neonatal correction of squint was performed between 1-1½ years.
illness including respiratory distress syndrome, After one year the followup visits were scheduled every
surfactant therapy, neonatal jaundice, sepsis, shock, 3 monthly for 12 months and thereafter every 6 monthly
hypoglycemia, necrotising enterocolitis were noted. All to age of 3 years. At each followup visit, an assessment
babies were screened for ROP performing indirect of the baby’s neurodevelopment was made by the
ophthalmoscopy under full pupillary mydriasis at the neonatologists at the tertiary care multispeciality
NICU or at our tertiary care retina clinic. Mydriasis was hospital. OAE (Oto acoustic emission) to assess hearing
achieved by instillation of 1:1 dilution of tropicacyl with was performed before discharge and also at 3 months
phenylephrine. The zone of involvement, the stage of after discharge. Those babies with suspected hearing
the disease, presence or absence of PLUS or RUSH loss were subjected to Brainstem evoked response
disease was noted. The fundus appearance was audiometry (BERA) as a definitive indication of hearing
classified into three (1) Immature peripheral retinal loss. Assessment for neurosensory development was
vasculature (2) prethreshold ROP (3) threshold ROP performed by the Denver Developmental screening test
as in the ICROP study 11. Prethreshold ROP was defined (DDST) and the Development assessment scale for
as zone-I involvement in any stage of disease, zone II Indian infants (DASII) at ages 3, 6, 9 and 12 months.
stage II, plus disease, zone II involvement with a stage A thorough neurological workup was also performed
less than threshold ROP. Threshold ROP was defined at age 1, 3, 6, 9, 12 months and the Amiel Tison test
as stage 3 disease in zone I or II with 5 contiguous or for hypertony and spasticity was assessed at each
8 total clock hours of involvement with plus disease. evaluation.
The babies were divided into two groups, those with
threshold ROP and those without threshold ROP and Results
the birth weight, gestational age and various risk factors
compared between the two groups. 130 consecutive preterm babies with gestational age
<33 weeks were screened for ROP and assessed for
The protocol for screening employed by us was as perinatal morbidities and neurosensory development.
follows. The initial screening was performed before This study group constituted the inpatients of the
31 weeks post conceptional age or within 4 weeks of tertiary care NICU of a multi-speciality hospital in
chronological age. The follow up schedule was based Trivandrum and included both in-born and out-born
on the fundus findings and stage of ROP. Babies whose

164 Kerala Journal of Ophthalmology Vol. XX, No. 2

babies. The mean age was 30.30 weeks (Range 25-32 Table 3. Showing Treatment Characteristic for Preterms with
weeks) and the mean birth weight was 1367.9 gms Threshold ROP
(730-2400 gm).
Treatment Babies/Eye Percentage

Thus out of 130 preterm infants of gestational age Laser Ablation 12 babies 85.71 %
<33 weeks who were screened, 30 % had immature Cryotherapy 2 babies 14.29 %
vasculature, 10 % prethreshold and 11.7 % (14 babies) RD Surgery 1 Eye
had threshold ROP (Table1). Out of these 14 babies, Repeat laser 6 Eyes 3.57 %
3 were twins and one baby belonged to a quadruplet 21.43 %
pregnancy. The 14 babies with threshold ROP were
further analysed with respect to the mean gestational Table 4. Showing Ocular Findings on Followup in Patients
age and birth weight. Analysis of this data showed that with threshold ROP
these were ELBW babies (extremely low birth weight
babies) with a mean gestational age of 28.25 weeks Treatment Babies/Eye Percentage
(range 25 weeks-31 weeks) and birth weight of 1048.57
gm (850-1200 gm). Of these 64.3 % babies had a Refractive Errors 12 Eyes 42.85%
gestational age ≤ 28 weeks, 85.7 % were ≤ 30 weeks Myopia 8 66.67%
while 14.4 % were > 30 weeks. The difference between Hypermetropia 2 16.67%
birth weight and gestational age in the pre terms and Astigmatism 2 16.67%
those with threshold ROP with significant statistically Severe Visual Loss 2
(TABLE :2) Esotropia 3 7.14%
Disc + Macular Drag 4 14.28%
28.57%

Table 5. showing characteristics of threshold ROP babies with
strabismus

Preterm babies with threshold ROP underwent Strabismus( Esotropia) 3
cryotherapy to the peripheral retina (2 patients) under Cryotherapy 2
short general anaesthesia or peripheral retinal laser Myopia 5
ablation to the ischemic retina anterior to the ridge Astigmatism 1
under topical anaesthesia (12 patients). Following Macular and Disc Drag 3
treatment the babies were reviewed daily and the Nystagmus 2
fundus periphery assessed for skip lesions. 6 eyes Neurodevelopmental Delay 2
required additional laser after 2 days. In 2 eyes of two
patients the retinopathy progressed to stage 4b for (21.4 %) had bilateral neovascularisation of iris and
which scleral buckling was performed. The post tunica vasculosa lentis which regresed after laser
operative outcomes in both was poor. Both eyes became ablation. Two of these patients later developed stage
phthisical (7.14 %). Thus there was 7.14 % severe visual 4b ROP in one eye.
loss in this group. In patients with ROP; 3 patients
Analysis of followup data at one and a half years of age
Table 1. Analysis of Fundus findings showed esotropia in 3 patients (21.4 %); refractive error
in 28.57 % with 87.5 % being myopia (≥ 3.00D Sph)
Fundus Findings No. of Babies Percentage and 12.5 % hypermetropia (≥ +2.00D sph). 4 babies
had disc and macular drag (28.57 %) out of which
Normal 58 48.30% 2 had undergone cryo and the other laser. All the
Immature Vasculature 36 30.00% 3 patients with esotropia had macular drag and
Demarcation Line nystagmus was present in two. Two patients who had
Prethreshold 6 5% undergone cryotherapy were myopic and had esotropia.
Threshold 6 5% Two of the three babies had mild neurodevelopmental
Total 14 11.70%
120 100%

Table 2. Comparing Gestional Age and Birth Weight in Preterms with ROP.

Preterms Threshold ROP P value

Mean Gestational Age (Range) 30.30weeks (25-32 weeks) 28.28 weeks (25-31 weeks) 0.0001
Mean Birth Weight 1357.9 (730-2400gm) 1048.57 (850-1200gm) 0.0001

June 2008 Valsa Stephen et al. - ROP Screening 165

delay. Two more preterm babies who did not have ROP seen in 2/64 screened (3.1 %). Correlating the NDD
during screening developed esotropia on follow up. In with gestational age showed that major NDD or death
one the accommodative component was predominant. occurred in 42 % of preterm babies with gestational
Thus our series had a total of 5 babies (3.8 %) with age ≤ 28 weeks in comparison to 9 % of babies with
strabismus. In the group with no ROP the incidence of
strabismus was 1.7 % only. Table 7. Predictors of Adverse Outcomes in Neurodevelopment

Associated perinatal morbidity in our children in whom Abnl NDD Abnl NDD P value
threshold ROP was detected during screening are given
in TABLE-6 comparing them to babies without threshold Risk + Risk -
ROP. Thus it can be seen that respiratory distress and
multiple apnoeas and sepsis are more common in the ≤ 28 42 9 0.001
group with threshold ROP while necrotising
enterocolitis shows marginal increase in incidence. Ventilation 17 0 0.009
Respiratory distress, multiple apnoeas,and sepsis were
found to be statistically significant. Though ventilation SPDA 27 10 0.035
was statistically significant the incidence in those with
ROP was less compared to the other group. Shock 25 6 0.054

Four babies (28.57 %) showed mild neuro developmental Multiple Apnoea 15 5
delay- three in mental and motor development and one
in language delay. There was no morbidity. gestational age > 28 weeks (P=0.001) Table:7.

The neurodevelopmental followup was carried out in Thus the bad outcome determinants for major
the neurodevelopmental clinic at KIMS Hospital in neurodevelopmental delay were
63.3 % of babies . An abnormal neurosonogram was
seen in 10 % of the 130 babies screened. 8 babies died 1) Gestational age ≤ 28 weeks
before discharge and all of them had abnormal
neurosonogram and intraventricular haemorrhage 2) Need for ventilation
> grade 2.
3) Abnormal (> Gr 2 IVH) neurosonogram
Failed hearing screening (OAE) and definitive BERA
was seen in 1 out of 92 babies screened (1.1 %). 4) Shock
Abnormal neurological examination (tone/reflexes)
and DASII motor score < 70 at 9 months of corrected 5) sPDA
age was seen in 3 out of the 64 screened (4.7 %) DASII
mental score of < 70 at 9 months corrected age was 6) Recurrent apnoeas

Regarding visual outcome the bad outcome
determinants were extreme prematurity < 28 weeks,
history of respiratory distress and multiple apnoeas,
sepsis , birth weight < 1200 gm; tunica vasculosa lentis,
and need for repeat lasers with poor response to
treatment. Cryo treated babies had a higher incidence
of myopia ≥ 3.00D Sph; disc and macular drag,
esotropia and nystagmus. Strabismus was associated
with higher risk of neurodevelopmental delay.

Table 6. Perinatal Mobidity in preterm babies with ROP

Threshold ROP No Threshold ROP P Value
No. of Babies Percentage
Sl. Risks No.of Babies Percentage
No.

1 Ventilation and Oxygen Administration 10 71.43% 85 78. 5 % 0.0003
2 Respiratory Distress and multiple ap noeas 10 71.43%
3 Neonatal Jaundice 7 19 17.92% 0.01
4 Sepsis 8 50%
5 PDA 2 57.14% 92 86.79% 0.005
6 NNEC 3 14.28%
7 Shock 2 21.43% 36 33.96% 0.03
8 Hypoglycemia 2 14.28%
14.28% 21 19.81% 0.34

19 17.92% 0.33

388 35.84% 0.058

20 18.87% 0.39

166 Kerala Journal of Ophthalmology Vol. XX, No. 2

Discussion lower birth weight and gestational age babies survived.

There is paucity of data from India on the long term In our study, 2 eyes (7.14 %) progressed to stage 4b
visual and neurological outcome of very low birth and became blind in spite of treatment. Both had
weight infants. This study aimed to undergone laser therapy. Both had severe tunica
vasculosa lentis at the time of laser. Gnanaraj L et al 23
(1) Analyse various factors that act as predictors of also reports a similar incidence of 10 % severe visual
poor visual outcome and neurodevelopmental loss in ROP treated eyes.
delay in extremely low birth weight premies On follow up the incidence of strabismus was 21.4 %
≤ 1250 gms. in the threshold ROP group and 1.7 % in the no
threshold ROP similar to the study by Theng et al 13.
(2) To provide anticipatory guidelines to parents and All were esotropic. Refractive error was seen in 28.57 %
help them plan rehabilitation of their precious with 66.67 % being due to myopia > -3.00 D sphere.
child. Premature babies with ROP have been reported to have
higher rates of myopia and strabismus especially in the
(3) To provide a model for developing a regional data cryotreated group .13,24 Strabismus is found to
base. develop predominantly in the treated group and is
frequently associated with neurological damage and
In our study the incidence of threshold ROP was amsometropia 24 . Here two of the three patients with
13.3 %. This is similar to a study by Theng JT et al 13 strabismus had mild neurodevelopmental delay. All had
(14.2 %). The mean gestational age was 28.28 weeks
with a range of 25 – 31 weeks and mean birth weight Fig. 1. Bar diagram showing gestational age distribution in
was 1048.57 gms (850-1200 gm). A study in India babies with and without threshold ROP.
showed that the mean birth weight of babies
undergoing laser or surgery was 1254.5g (range 710 macular ectopia (5 eyes were myopic while one was
to 2000) and the mean period of gestation was 29.6 mixed astigmatic). Two of them had been cryotreated
weeks 14, while another had 1554g (range 850 to 2290) supporting the hypothesis that cryo leads to increased
and 31.75 weeks (28-34) as the mean birth weight and incidence of strabismus and myopia. However
gestational age 15. Many other studies in India have according to Yu YS et al 8 only acute inflammation
shown threshold ROP occurring in babies > 1250 gm occurs to the muscle fibre during cryotherapy and does
and 1500 g 16,17 .There are also various reports of ROP not result in long term structural change. Therefore
seen in larger, bigger babies in Asia .20,21 However in strabismus is attributable to other reasons. According
our study, no babies were >1200g. This is similar to to Pennefather PM et al, increased risk of strabismus is
studies conducted in the West 18,19 which report no seen with cicatrical retinopathy of prematurity,
incidence in babies > 1250g +/- 100g. According to refractive error, family history of strabismus and poor
Vedantham 22, the difference between developed and neurodevelopmental outcome .25,26
developing countries might reflect the failure of very
small infants to thrive and the quality of neonatal care
in developing countries.Thus the discrepancy in our
study compared to other Indian studies may be due to
the fact that our study was in a tertiary referral
multispeciality hospital with state of art NICU facilities
where only the most high risk babies were referred and

Table 8. Neurodevelopment Follow-Up

z Assessment Performed 63.3%.
z Abnormal Neurosonogram (>Gr II IVH) : 10%
z DASII Motor Score < 60:4.7% (Cerebral Palsy)
z DASII Mental Score < 70:3.1% (Mental Retardation)
z Defective BERA : 1.1%

June 2008 Valsa Stephen et al. - ROP Screening 167

On analysis of the perinatal risk factors, respiratory Therefore this cannot be extrapolated as a population
distress and multiple apnoeas, sepsis (0.03) were found based data base. Pooling together available data, longer
to be significant risk factors for the development of followup in larger series of preterm babies will help
threshold ROP. The occurrence of ROP correlates with form a definitive data base from our country.
more supplemental oxygen and the administration of
CPAP according to Wagner RS 26. In India, Rekha et al 27 References
reported that duration of oxygen therapy and anemia
were independent factors predicting the development 1. Volconico A; Accorsi.P, Sanzeni.C et al. Mid and long
of ROP. Dutta et al 28 reported administration of packed term outcome of extremely low birth weight infants:
cell and double volume exchange transfusion as and analysis of prognostic factors. J.Matern. Fetal
risk factors for development of threshold ROP. Neonatal Med 2007, Jun; 20(6):465.
Venekar et al 29 found “out born”, RDS and exchange
transfusion as independent risk factors for severe ROP 2. Barbara Schmidt MD.Msc; Elizabeth.V.Asztalus MD et
in babies > 1250 gms. al. Impact of bronchopulmonary dysplasia, brain injury,
and severe retinopathy of Prematurity in low birth
Neurodevelopmental delay in the preterm babies came weight infants at 18 months JAMA.2003; 289:
to 4.7 % (cerebral palsy ) and 3.1 % (mental retardation). 1124-1129.
However in the threshold ROP group, three babies
(21.4 %) showed mild developmental delay while one 3. O’Connor A.R, Fielder A.R Visual outcome and perinatal
baby showed language delay (total 28.57 %). Severe adversity.
ROP has been found to be significantly associated with
neurosensary development impairment in children 2. 4. Fledelius et al. Preterm delivery and subsequent ocular
In our study the bad outcome determinants for development .A 7-10years followup of children screened
neurodevelopment and visual outcome were similar for ROP. Acta Ophthalmol Scand 1996 Jun; 74(3):
with respect to gestational age, need to ventilate and 294-6.
recurrent apnoeas. Thus there appears to be correlation
between the development of the two. 5. Bianchi PE; Guaglino R et al. Esptropia and pseudo
exotropia in acute ROP sequlae: Clinical features and
Thus to conclude, there is an urgent need to followup suggestions for treatment. Eur.J.Ophthalmol.1996 Oct-
these preterm babies who survive the perinatal Dec; 6(4):446-50.
morbidity especially with respect to visual and
neurodevelopment and behavioral development. 6. Pennefather PM, Clarke MP etal. Risk factors for
Awareness of the various risk factors and its significance strabismus in children born before 32 weeks gestation.
on the long term development of the baby will help Br.J.Ophthalmol 1999 may; 83 (5) 514.
guide the parents to plan their child’s future. A proper
screening and early treatment of Retinopathy of 7. Holmstrom G et al. Ophthalmological followup of
Prematurity, correction of associated refractive errors, preterm infants: a population based prospective study
surgical correction of squint, training of parents and of visual acuity and strabismus. Br.J.Oph.1999 Feb;
the child to use low visual aids will go a long way in 83(2):143.
preventing amblyopia, and help in the visual
rehabilitation and optimum neurodevelopment of the 8. Theng J.T; Wong T.Y, Ling Y. Refractive error and
visually impaired child. strabismus in premature Asian infants with and without
retinopathy of Prematurity. Singapore med.J 2000 Aug
The limitations of this study are its small sample size. 41(8):393-7.
Maternal factors and antenatal factors predisposing to
the development of threshold ROP were not studied. 9. Yu YS; Shin K.C, Kim NR et al. Extraocular muscle
The major bias is that the results presented here are changes after cryotherapy for retinopathy of Prematurity
the results from a single NICU which is a tertiary referral and the development of strabismus in premature
centre and hence high risk babies are referred here. infants. Korean.J.Ophthalmol. 2001 dec, 15 (2):87.

10. Sahni.J, Subedhar NV etal. Treated threshold 3 versus
spontaneously regressed subthreshold stage 3
retinopathy of Prematurity : a study of motility,
refractive and anatomical outcomes at 6 months and
36 months. Br.J.Ophthalmol 2005 Feb; 89(2):154.

11. An international classification of retinopathy of
Prematurity. The committee for the classification of
Retinopathy of Prematurity. Arch. Ophthalmol 1984;
102:1130-4.

12. Multicenter trial of cryotherapy for retinopathy of
Prematurity. Three month outcome. Cryotherapy for
retinopathy of Prematurity cooperative group. Arch.
Ophtalmol 1990; 108:195-204.

13. Theng J.T, Wong TY, Ling Y: Refractive errors and
strabismus in premature Asian babies with or without

168 Kerala Journal of Ophthalmology Vol. XX, No. 2

retinopathy of Prematurity. Singapore med. J 2000. Aug 22. Vasumathy Vedantham: Editoral: Retinopathy of
41(8):393-7. Prematurity screening in the Indian population . It’s
time to set our own guidelines! Indian J.Ophthalmol.
14. Jalate S, Matalia J, Hussain A et al. Modification of 2007:55:329-30.
screening criteria for retinopathy of Prematurity in India
and other middle income countries. Am J Ophthalmol 23. Gnanaraj L, Brennan R, Cottrell DG. Retinopathy of
2006; 141:966-8. Prematurity in practice. Long term results following
treatment for threshold disease. Eye 2003 march
15. Shah PK, Narendran V et al Fulminate retinopathy of 17(2):189-93.
Prematurity: Clinical characteristics and laser outcome.
Indian J. Ophthalmol 2005; 53:261-5. 24. Sahni J, Sutbhedar NV, Clark D. Br.J.Ophthalmol 2005
Feb 89(2):127-8. Treated threshold stage 3 versus
16. Dogra MR, Narang S, Biswas C et al. Threshold spontaneous regressed subthreshold stage 3 retinopathy
retinopathy of Prematurity: Ocular changes and of Prematurity: A study of morbidity, refractive and
sequelae following cryotherapy Indian J Ophthalmol anatomical outcomes at six months and 36 months.
1998;46:15-9.
25. Holmstrom G et Azazimet al. Ophthalmological folowup
17. Deshpande D, Chat Urubedi M, Copal L et al. Treatment of preterm infants: A population based prospective
of threshold retinipathy of Prematurity. Indian J study of visual acuity and strabismus. BJO 1999 Feb
Opthalmol 1998; 46:15-9. 83(2):143.

18. Goble RR, Jones HS, Fielder AR. Are we screening too 26. Pennefither PM, Clarke MP et al. Risk factors for
Many babies for retinopathy of Prematurity? Eye strabismus in children born before 32 weeks gestation.
1997:11:509-14. Br J Ophthalmol 83(5):514.

19. Ianovoth TL, Siatkowski RM, Mc Caffree MA et al. 27. Rekha S, Battu RR. Retinopathy of Prematurity: Incidence
Retinopathy of Prematurity in infants in the birth weight and risk factors. Indian Pediati 1996:33: 999-1003.
>1250 gms- Incidence severity and screening guidelines
cost analysis. J AAPOS 2006; 10: 128-34. 28. Dutta S, Narang S et al. Risk factors of threshold
retinopathy of Prematurity. Indian Pedaiti 2004; 41:
20. Phan MH, Nguyen PN, Reynolds JD. Incidence and 665-71.
severity of Retinopathy of Prematurity in Vietnam, a
developing middle income country. J Pediact 29. Vinekar A, Dogra MR et al. Retinopathy of Prmaturity
Ophthalmol Strabismus 2003:40:208-12. in Asian Indian babies weighing greater than 1250 gms
at birth. Ten year data from a tertiary care centre in a
21. Chen Y Characteristics of severe retinopathy of developing country. Indian J Ophthalmol 2007:55:
Prematurity patients in China. A repeat of the first 331-35.
epidemic ? Br J Ophthalmol 2006:90:268-71.

June 2008 N. Bindu - Fungal Keratitis 169

CURRENT
CONCEPTS

Fungal Keratitis

Dr. N. Bindu MS

Fungal infections of the cornea constitute an important Aetiology
eye problem in outdoor workers in tropical &
subtropical countries.Favourable humid climate and Fungal ulcer affects young healthy adults (21-60 yrs)
large agricultural & manual labourer population makes who live in rural areas - agriculture being their main
fungal keratitis common here. 30-50 % of culture occupation. Males are commonly affected as they do
proved suppurative keratitis of non viral origin is most outdoor works than females. Majority of patients
constituted by fungal keratitis. are immunocompetent without any external eye
disease.
Globally there has been an increase in number of
reported cases of fungal keartitis. Increasing use of Epidemiology
antibiotics, injudicious use of steroids, increasing
laboratory capability for recovering fungi from infected Aspergillus species is the most common organism
corneas and an increased awareness all have responsible for fungal keratitis world wide.
contributed to this.
India 27-64 %
Fungi causing human keratitis Aspergillus - 6-32 %
Fusarium - 2-29 %
A. Hyaline Filamentous fungi Pencillium -
Fusarium ( F.solani,F.oxysporum)
Aspergillus (A.fumigatus,A.flavus) In northern India, Nepal & coastal Karnataka Aspergillus
Scedosporium is found to be more frequently involved. In Southern
Pencillium(P.spinulosum,P.cetrinum) India, Fusarium is reported as the leading etiologic
Acremonium(Cephalosporium) agent. Candida is very rare in India as causative organism.
Paecilomyces
Predisposing factors
B. Dematiaceous Filamentous fungi
Curvularia(C.lunata,C.geniulata) - Local
Bipolaris - Systemic
Exserohilum
Cladosporium Local
Coelomycetes
1. Trauma- injury to the cornea with vegetable
C. Yeast like fungi matter or organic matter is reported in 55-65 %
Candida (C.albicans) of fungal keratitis

Department of Ophthalmology, Medical College, Kozhikode 2. Contact lenses- In industrialised countries contact
lens wear has been identified as a risk factor (29 %).

170 Kerala Journal of Ophthalmology Vol. XX, No. 2

Patients wearing any type of contact lens can get Fig. 3. Stromal abscess, Fig. 4. D e r m a t e a c e o u s
fungal keratitis endothelial plaque-
fungi-brown
3. Iatrogenic – following cataract surgery, refractive Fusarium
surgery, LASIK, penetrating keratoplasty pigmented ulcer-

4. Topical steroid use - 4-30 % has been reported in curvularia
various studies. Steroid use tend to activate and
increase virulence of fungi Other features

5. Other factors-corneal surface disorders, Immune ring
dry eye, bullous keratopathy, exposure keratitis, Posterior corneal abscess
allergic conjunctivitis are associated with the Endothelial plaque
development of mycotic keratitis
Rarely fusarium lead to endophthalitis.
Systemic factors-
Depending on aetiological agent each case may vary.
Diabetes-5%
Malnutrition -1% Fusarium species usually produce severe keratitis
Alcoholism – rare leading to perforation, deep extension and malignant
HIV – rare glaucoma

Chronically ill & intensive care unit patients are prone Aspergillus & curvularia produce less severe ulceration
to develop candida infection. and are more amenable to therapy.

Clinical features Microbiological investigations

Symptoms – may not present as acutely as with other Microbiological investigatons should always be
form of microbial keratitis, Usually signs of performed where fungal infections of cornea is
inflammation is minimal and absence of lid edema is a suspected, as it is not possible to distinguish between
common feature. bacterial and fungal keratitis on clinical findings alone.
It includes the following
Signs – greyish white/yellowish white infiltrates
Smears
Ulcer base filled with soft, creamy, raised infiltrates Staining
Fungal culture
Feathery borders or hyphate edges – in 70 % PCR
Confocal microscopy
Hypopyon –solid hypopyon with convex upper border-
in 55 % Direct microscopic evaluation-

Satellite lesions -10 %

Dematiaeceous fungi keratitis shows black/brown
pigmented surface which is dry, rough, leathery and
difficult to scrape (fig 1, fig 2, fig 3)

Most valuable and rapid diagnostic tool for detection
of fungal elements. Corneal scrapings are obtained by
scraping the base and edges of the ulcer with sterile
blade or spatula several times.Smears should be made
as thin as possible.

Fig. 1. Feathery margins- Fig. 2. Immune ring, pseudo Stains used & their sensitivity 45-73 %
dendrites- Aspergillus Gram stain 66 %
fusarium Giemsa stain

June 2008 N. Bindu - Fungal Keratitis 171

Lactophenol cotton blue 70-80 % Calcoflour white
Grocott’s methanamine silver 89 %
Calcoflour white Fungal hyphae and yeast cells are delineated against
KOH 10 % wet mount 80-90 % dark background seen even in thicker preparations also.
80-90 % Acanthamoeba cysts and P. carini can also be
Fig. 5. KOH wet mount-fungal filaments detected,but it requires UV microscope.

Culture

Fungal growth usually occurs within 3-4 days
(48-72 hrs) but may require incubation upto 4-6 weeks.

Sabo0raud’s dextrose agar is used frequently. It
is kept at room temperature.Initial growth occurs within
72hrs in 83% and within 1week in 97 % cultures.
(fig 7).

Is a simple, cheap, rapid test and easy to interpret even
by ophthalmic technicians. It is an ideal method for
practice in developing countries. KOH can be
counterstained by India ink,PAS and acridine orange.

Gram stain- Fig. 7. Saboraud’s agar- Aspergillus

Stains yeast cell and fungal hyphae equally well. It can Blood agar-also yields good positivity
identify bacteria also.
Thioglycollate broth and brain heart infusion are not
Lactophenol Cotton Blue (fig 6)-detect all common necessary routinely.
ocular fungi. It is commercially available and has long
shelf life. Corneal biopsy

Done if smears and cultures are negative in highly
suspicious cases. Done under local anaesthesia using
2-3 mm trephine. Corneal button obtained from
therapeutic PKP can also be used. Histopathology
reveals the presence of fungal elements (fig. 8).

Fig. 6. Lactophenol cotton blue-aspergillus

Grocotts methanamine silver stain Fig. 8. Corneal biopsy- showing fungal filaments

Fungal cell walls and septa are clearly delineated
against pale green background. Can identify
acanthamoeba cysts and P. carinii.

172 Kerala Journal of Ophthalmology Vol. XX, No. 2

Suggested lab workup Amphotericine B –

KOH wet mount with or without stain Available as systemic preparation(fungizone)
Gram staining
LCB Topical drops is prepared by diluting with dextrose or
Culture in SDA and blood agar distilled water to a concentration of 0.15-0.5 %. Other
routes of administration are
Other methods
Subconjunctival-10 micrgrams
Impression debridement Intracameral – 5-7 micrograms
Intravitreal – 10 micrograms
Cellulose acetate filter paper is applied on to the Intravenous -0.1 mg/kg bodyweight.
ulcerated part, stained and examined.
It covers Candida and Aspergillus but is not effective
PCR against Fusarium. It is used as first line of therapy in
Candida.
Is an effective method of diagnosing fungal keratitis
because it offers increased sensitivity and significant Azoles
reduction in time (4 hrs) to establish diagnosis. Drug

Confocal microscopy Topical Oral Parenteral
%
Is a non-invasive invivo examination technique. Can
reveal hyphal elements and yeast forms.It is more Ketoconazole 1-2 200-600 mg
sensitive than culture
Miconazole 1-2 200-400 mg 600-1200mg/d

Medical Therapy Econazole 1

Therapy of fungal keratitis is unsatisfactory. Antifungal Clotrimazole 1-2 60-100 mg
agents available are mostly fungistatic and requires
prolonged therapy. Fluconazole 1 100-400 mg 2mg/ml

Itraconazole 1-2 200-400 mg

Available commercially as Auroclot, nistin-

Response to therapy is slow and the result is better in (clotrimazole), Aurozole (econazole)
non severe ulcers

Drugs available for treatment Treatment protocol

Polyenes Amphotericin Specific antifungal therapy
Azoles Nystatin
Natamycin Depend on availability of the drugs and the results of
Azoles Imidazoles lab study and severity of ulcer
Pyramidines Clotrimazole
Miconazole If hyphae are seen –natamycin or amphoterecin
Econazole topically
Ketoconazole
Triazoles If yeast/pseudohyphae seen- amphotericin/
Fluconazole fluconazole/ flucytosine
Itraconazole
5-Flurocytosine Dosage –topical eye drops hourly during day and 2
hourly at night
Natamycin –
In deep keratitis / endophthalmitis / scleritis / after
Available as 5 % suspension (Natamet, Nata, Elmycin) PKP-oral ketoconazole /itraconazole /fluconazole given

It is the drug of choice in filamentous fungi. It is effective Miconazole is the drug of choice in paeciliomyces
against Fusarium, Aspergillus, Curvularia and Candida
Amphotericin and imidazole are antagonistic.

Treatment should be maintained for 6-12 weeks

June 2008 N. Bindu - Fungal Keratitis 173

Antimicrobial activity of antifungals based on published reports.

drug Aspergillus Candida Csporium Cladosp Curvulari Fusarium Paecilio Pencillium

Amph-B SS R
S
Nystatin SS I

Natamycin S SSS S S
S
Clotrimazole SS SS I
i
Miconazole SS SI

Econazole SI SS

Ketoconazol IS SS

Fluconazole SS

Flucytosine S S RR

S-susceptible, I- variable, R-resistant

Surgical therapy Prolonged medical treatment and prompt timing of surgical
intervention are required to increase chances of cure.
a) Frequent corneal debridement-
Emphasis on prevention and early diagnosis of this
Mechanical debridement of corneal epithelium helps potentially blinding disease.
in debulking fungi and enhances drug penetration.
References
It is done with spatula/blade using slitlamp under local
anaesthesia every 24-48 hrs 1. Srinivasan M. Fungal keratitis.urrnt opinion
ophthalmology 2004; 15:321-7
b) Therapeutic keratoplasty
2 Agarwal V, Biswas J, Madhavan HN, Mangal G, Reddy
It is the ideal method to treat nonhealing fungal keratitis MK, Saini JS et al Current perspectives in infectious
threatening perforation.Structural integrity and keratitis IJO 1994: 42:171-91
eradication of sepsis is achieved in 80-90 % of cases.
3. Prajna NV, John RK, Nirmalan PK, Lalitha P, Srinivasan
Lens should be left undisturbed as far as possible to M.A Randomized clinical trial comparing 2 % econazole
prevent posterior extension. and 5 % natamycin for the treatment of fungal keratitis.
BJO 2003:87:1235-7
Topical antifungal therapy is to be continued. In
addition systemic antifungals to be given for 6-8weeks. 4 Bunya VY, Hammersmith KM, Rapuano CJ, Ayres Bd,
Cohen EJ. Topical and oral voriconazole in the treatment
Use of post operative steroids topically is controversial of fungal keratitis. AJO 2007:143:151-3

Other surgical modalities 5. Philip A. Thomas -Fungal corneal ulcers: EYE-Nov:
Cyanoacrylate glue 2003. Vol 17:852-862
Conjunctival flap
Amniotic membrane transplantation 6. A Panda, MDeb, P Sony, MS Pathengey Are we looking
for only fungus in clinical keratomycosis? DOS Aug
Conclusion 2002: Vol 8, 15-7
Diagnosis and treatment of fungal keratitis can be quite
challenging. 7. M. Srinivasan Fungal Keratitis DOS Times Sep 2003:
Vol 9, 135-139
Microbiological investigation is essential for correct
diagnosis and treatment. 8. George Alexandrakis Keratitis, Fungal E-Medicine may
27 2005

9. CORNEA-Krachner Chapter 98 -Fungal Keratitis
10. Myron Yanoff. Jay. S. Duker Ophthalmology second

edition, Vol 1-Fungal Keratitis 483-485
11. Eye Rounds, org:case 59-Fusarium-Fungal Keratitis,

webeye, ophth.uiowa.edu/eyeforum/cases/59-
Fusarium-Fungal keratitis-ReNu-moistureLoc.htm
12. Brasnu E, Bourcier T, Dupas B, Degorge S, Rodallec T
et al. In vivo confocal microscopy in Fungal keratitis.
BJO 2007;91:588-91

174 Kerala Journal of Ophthalmology Vol. XX, No. 2

OCULAR
PHARMACOLOGY

Vital Dyes For Chromovitrectomy: Colours
for the Vitreoretinal Surgeon!!!

Dr. Meena Chakrabarti MS DO DNB, Dr. Valsa Stephen MS DO DNB, Dr. Sonia Rani John DNB,
Dr. Arup Chakrabarti MS DO

Chromovitrectomy 1 refers to the application of vital First Generation: (2000): Indocyanine Green2 (ICG)
dyes during retinal surgery to visualize preretinal tissues
and membranes. Chromovitrectomy arises from the Second Generation:(2003): Infracyanine Green3
difficulty in visualizing and removing the several thin (IFCG), Trypan Blue4 (TB) and Triamcinolone
and transparent tissues in the vitreoretinal interface accetonide 9 (TA)
including the internal limiting membrane (ILM),
epiretinal membrane (ERM) and the vitreous. These Third Generation (2005): Brilliant Blue G5 (BBG),
tissues are involved in the pathogenesis of several Chicago Blue7, Bromophenol blue7, Patent blue8 (PB).
macular disorders including macular holes and diabetic
macular oedema. Surgical manipulation of these poorly Table 1 gives the comparison of staining characteristics
visualized tissues have been shown to induce gliosis, and structures of various dyes used for chromo
iatrogenic chorioretinopathy and phototoxicity. Staining vitrectomy.
of these tissues with vital dyes may improve their visibility,
enhance the ability to peel them as well as ensure Indocyanine Green (ICG)
complete removal of all tissues, which may lead to a better
visual result postoperatively with a lesser recurrence rate. ICG is a tricarbocyanine anionic dye with a molecular
formula of C43H47N2NaO6S2 and a molecular weight
An ideal vital dye for chromovitrectomy should have of 775 Daltons. This green dye has amphiphilic
the “ability to selectively stain” the internal limiting properties and hence interacts biochemically with
membrane and the epiretinal membrane, leaving the different human tissues. ICG demonstrates greatest
retina unstained. It should provide adequate colour affinity to the extracellular matrix components10 of the
difference between the stained ILM/ERM and the ILM, thereby exhibiting an ability to selectivity stain
normal retina. Other favorable characteristics are the ILM.
1) rapid elimination from vitreous cavity 2)
photochemical stability 3) solubility in balanced salt Chromovitrectomy using ICG for dye assisted peeling
solution 4) absence of toxicity and 5) an adequate light of ILM gained acceptance for the management of
absorption profile. macular holes11, 12, 13, 14. Its use was later extended to
improve visualisation of the glial ERM15, 16, proliferative
The vitreoretinal interface staining agents have been membranes of proliferative diabetic retinopathy (PDR)
used since 2000. They can be classified into three and proliferative vitreoretinopathy (PVR)17.
generations depending on the time of introduction.
Controversial reports on the toxic effects of ICG have
Chakrabarti Eye Care Centre, Kochulloor, Trivandrum - 695 011 been published 18. These included Muller cell, RPE18
E-mail: [email protected] and ganglion cell damage; visual field defects and optic
atrophy 1, .2,17,18

June 2008 M. Chakrabarti et al. - Vital Dyes 175

Histopathology of the peeled ILM after ICG assisted 1. Perform a fast surgical procedure in order to minimize
ILM peel during chromovitrectomy revealed the the duration of contact with RPE cells and to minimize
presence of cellular structures on and under the ILM19,20. the ICG exposure to light from endo illuminator.
Detection of the presence of retinal elements (plasma
membrane of Mullers cells, myofibrocytes, astrocytes) 2. Use ICG concentrations lower than 0.5 mg/ml to
on the peeled ILM raised the issue of retinal damage minimize the risk of RPE damage and possible
during peeling. Animal studies and in-vitro experiments retinal toxicity.
indicated a dose dependent ICG mediated toxicity to
retinal elements (Mullers cells, ganglion cells, 3. Avoid ICG injection direct through the macular hole
photoreceptors and RPE) 11, .21-24 The hypotonic ICG by any method to control ILM staining (slow
solution has been shown to cause osmotic damage to injection, use of the 20 gauge, prototype painting
the retinal cells. brush called vitreo retinal internal limiting
membrane color enhancer (VINCE) 31, or by use of
Exposure to ICG causes damage to the photoreceptors perfluorocarbons over the macular hole etc).
and RPE cells leading on to apoptosis or necrosis due
to light induced damage .25-27 Subretinal injection of Infracyanine Green (IfCG)
ICG in rabbit models may result in RPE damage even
in concentration as low as 0.5 mg/ml. IfCG possesses two well recognized pharmacological
differences from ICG, which vouches for its safe profile
There is paucity of published data comparing the effect in chromovitrectomy .32-35
of ILM peeling with and without the use of ICG.
1. IfCG is produced in a synthesis mode without sodium
Majority of studies (Table 2) used ICG in higher iodine. High dose of topical or intraocular iodine can
concentration and this factor could be responsible for induce severe corneal and retinal damage.
the toxicity. We suggest three safety measures when
using ICG for ILM peeling. 2. the presence of sodium iodine in the ICG solution
requires dilution in water resulting in a hypotonic

Table 1. Properties of dyes used for chromo vitrectomy

176 Kerala Journal of Ophthalmology Vol. XX, No. 2
Complication
Table 2. Meta analysis of Articles on ICG use.
Optic Atrophy
Sl.No Author Year Procedure Effect Optic Atrophy
MHS Worse functional outcome
1 Sheidow et al10 2003 Worse visual acuity
MHS when ICG used as adjuvant
2 Gass et al13 2003 Worse visual acuity when
MHS ICG used as adjuvant
3 Ando et al14 2004 Worse visual acuity when
ERM ICG used as adjuvant
4 HillenKamp J et al16 2006 No difference with and
MHS without ICG
5 Lochead et al28 2004 MHS No adverse effects
6 Slaughter and Lec29 2004 MHS No adverse effects
7 Rodrigues and Meyer30. 2007 No difference in anatomic
outcome.

solution of 248-275 m mol/kg. The iodine free IfCG is to stain the edges of an open retinal tear on subretinal
dissolved in 5 % glucose solvent generating an iso administration 44 facilitating its identificaion during
osmotic solution of 294 – 314 m mol /kg .36,37 vitrectomy.

IfCG in concentrations of 0.5 mg/ml selectively stains Triamcinolone Acetonide (TA)
the ILM just like ICG and has a much safer profile for
intravitreal use. Triamcinolone Acetonide (TA) is a synthetic insoluble
corticosteroid, with a chemical formula C24H31 FO6 and
Trypan Blue a molecular weight of 434 daltons. The white steroid
suspension has been used for chromovitrectomy since
The anionic hydrophilic azo dye trypan blue has a 2003 to visualize the transparent vitreous gel45 and the
chemical formula C34 H24 N6 O14 S4 and a molecular posterior vitreous cortex. Guo 46 et al compared the
weight of 960 Daltons. effectiveness of four biostains (triamcinolone acetonide,
indocyanine green, trypan blue and sodium fluoroscein)
This vital stain traverses the cell membrane in dead in delineating the vitreous and reported the best
cells thereby staining the dead tissues blue. In the 1990s visibility and contrast following use of triamcinolone
Trypan blue was first used intraocularly to stain the acetonide. In addition triamcinolone crystals get
anterior lens capsule to facilitate capsulorrhexis for deposited on the ERM and ILM making their
cataract surgery 38. The use of trypan blue in identification and peeling easier. The safety of
chromovirectomy is limited to the staining of ERM. It triamcinolone accetonide 47-50 to the retina has been
stains the ILM minimally sometimes necessitating demonstrated by several invivo and in- vitro studies.
repeated application to facilitate visualization. Trypan Marison VL 46 et al demonstrated that the vehicle
blue staining of ERM helps mark out its entire extent (benzyl alcohol) can induce toxicity to the retina in
thereby ensuring complete removal. rabbit models and hence the use of preservative free
triamcinolone acetonoide is recommended.
Clinical studies 39,40 have clearly demonstrated that
Trypan blue exerted little or no toxic effects on the Patent Blue
retina. Experimental data, however disclosed evidence
of retinal toxicity following trypan blue staining. Luke Patent Blue is a hydrophilic anionic triylmethane dye
et al 41 reported irreversible damage to the retina after with a chemical formula of C27 H31N2NaO6S2 and a
exposure to trypan blue in a bovine model. In contrast molecular weight of 582 Daltons. This dye has been
to this report Jin et al42, and Narayanan et al 43, showed used to stain the anterior capsule during cataract
that damage to the rodent neurosensory cells was dose surgery 17 in a concentration of 0.24 % . Patent blue
dependent and the toxicity could be eliminated at lower exhibit minimal systemic toxicity, carcinogenicity and
doses. A new indication for the use of trypan blue was

June 2008 M. Chakrabarti et al. - Vital Dyes 177

Table 3. The techniques used for staining the ILM.

Sl.No Technique Procedure Advantages Disadvantages
Higher retinal toxicity.
1 Air- filled Technique FAE to remove fluid from Concentrates dye at
vitreous cavity before dye injection. posterior pole. Less staining as dye is
washed out rapidly.
2 Fluid- filled technique Inj of dye intravitreously into the Immediate dye washout Not patented.
BSS/ RL filled eye. lesser retina toxicity.

3 VINCE (Vitreoretinal Painting brush constructed of Selective staining

Internal limiting a silicone tube connected to a

membrane color 20 G metal cannula, Diluted

enhancer.) dye in silicone cartridge.

mutagenicity 51. Preliminary clinical data demonstrates biostain at a concentration of 1.2 % to stain the anterior
a moderate affinity of patent blue to ERM and vitreous lens capsule intensively facilitating easy removal.
and a poor affinity to the ILM 52. Toxicity studies
revealed conflicting reports on retinal toxicity of patent Preclinical experiments on six novel vital dyes for
blue. Luke et al 53 demostrated that patent blue chromovitrectomy (Light green yellowish, E68, BrB,
exhibited mild and reversible retinal toxicity, whereas Chicagoblue, Rhodamine, Rhodulin blau- basic)
Westermeier et al 54 showed that RPE cells exposed in showed that BrB stained the ERM and ILM better, and
vitro to patent blue showed no toxicity. Analysis of was free of toxicity at concentration of 1.2 % and
available data indicate a safer profile for patent blue in 0.02 % 58. Similar reports have been obtained from
comparison to trypan blue, however the exact safe histopathological studies .59,60 At a higher concentration
dosage of patent blue for intravitreal injection remains of 1 % and 2 % enhanced ILM colouring was possible.
unclear. Further human clinical data on its safety profile and
defining its dosage and indications in chromovitrectomy
Brilliant Blue G is awaited.

Briliant blue G, also known as Coomassie or acid blue, Sodium Fluorescein
is a blue biostain with a chemical formula
C47H48N3S2O7Na and a molecular weight of 854 Daltons. Sodium Fluorescein is a hydrophilic xanthene dye with
Human and animal studies on the use of BBG for a chemical formula C20 H 10 Na 2O5 and a molecular
chromovitrectomy and anterior lens capsular staining weight of 376 Daltons. Abrams And coworkers 61 in
55,56 were published in 2006. These study results indicate 1978 demonstrated the efficacy of intravitreally injected
a safe clinical profile for both capsular staining and sodium fluroscein in staining the vitreous thereby aiding
chromovitrectomy. Absence of corneal endothelial cell its complete removal. The toxicity of sodium fluroscein
damage, no significant retinal pathological changes on to the retina has not been reported.
light and electron microscopy, no reduction in ERG
waves, and no clinical evidence of long term toxicity, Fluoromethalone Acetate (FMA)
were the hallmark results of these studies .55,56,57
Fluoromethalone Acetate (FMA) is a synthetic
The remarkable affinity to the ILM and absence of fluorinated glucocorticosteriod with an empirical
toxicity makes it a first real alternative to ICG and IfCG. formula C24 H31 FO5 and a molecular weight of 418
Daltons. Hata et al 62 performed pre-clinical
Bromophenol Blue (BrB) investigations of flurometholone acetate as a potential
new adjuvant during vitreous surgery. They found
(Tetrabromophenosulfonaphthalein) has a molecular neither reduction in ERG or histological changes
weight of 670 Daltons and a chemical formula following the use of Fluromethalone acetate and
C19H10Br4O5S. concluded that FMA could be used as an alternative to
TA during chromovitrectomy.
In cataract surgery BrB represents an appropriate

178 Kerala Journal of Ophthalmology Vol. XX, No. 2

Key issues 12. Sheidow TG, Blinder KJ, Holekamp.N.et al. Outcome
results of macular hole surgery: an evaluation of internal
1. Chromovitrectomy improved the visualisation of limiting membrane peeling with and without indocyanine
preretinal structures in vitreoretinal surgery. green. Ophthalmology 2003; 110: 1697-1701.

2. Intravitreal injection of dyes appear to be the most 13. Gass CA, Haritoglou C, Schaumberger M et al.
feasible approach to stain the vitreous and preretinal Functional outcome of macular surgery with and
tissues. without indocyanine green assisted peeling of the ILM
Graefes Arch clin Exp Ophthalmol 2003; 241: 716-720
3. Lower dye concentration and shorter exposure time
can limit side effects. 14. Ando.F, Sasano.K, Ohba N, et al. Anatomic and visual
outcomes after ICG assisted peeling of the retinal ILM
4. Various technique are available to stain ILM (Table 3) in Indiopathic macular hole surgery. Am.J. Ophthalmol
2004; 137: 744-746.
Newer vital dyes exhibiting selective staining of
preretinal tissue, and no retinal staining are less toxic 15. Rodrigues EB, Meyer CH, Schmedt JC, Kroll.P. Surgical
to the retina. management of epiretinal membrane with indocyanine
green assisted peeling (Letter) Ophthalmologica
References 2004;218:73-74.

1. Rodrigues EB, Meyer CH, Kroll P. Chromovitrectomy: a 16. Hillenkamp J, Saikia P, Herrmann WA et al. Surgical
new field in vitreoretinal surgery Graefes.Arch Clin.Exp. removal of idiopathic ERM with or without the
Ophthalmol 2005; 243:291-293 assistance of ICG: a randomised controlled clinical trail.
Graefes Arch Clin Exp Ophthalmol 2006; Dec 21.
2. Bruk SE, Da Mata AP, Snyder ME, et al. Indocyanine
green assisted peeling of internal limiting membrane. 17. Hiebl W, Gunther B, Meinert H et al. Substances for
Ophthalmology 2000; 107:2010-2014 staining biological tissues: Use of dyes in ophthalmology.
Klin Monatsbl Aug in beilkd 2005; 222:309-311
3. La Heij EC, Dieudonne SC, Mooy CM et al.
Immunohistochemical analysis of the internal limiting 18. Maia.M, Haller JA, Pieramici DJ et al. Retinal pigment
membrane peeled with infracyanine green epithelial abnormalities after internal limiting
Am.J.Ophthalmol 2005; 140: 1123-1125. membrane peeling guided by ICG staining. Retina 2004;
24:157-160.
4. Wong KL, Hiscott.P, Stanga.P, et al. Trypan blue staining
of the internal limiting membrane and epiretinal 19. Nakamura.T, Murata T et al. Ultra structure of the
membranes during vitrectomy; visual results and vitreoretinal interface following the removal of ILM
histopathological findings. Br.J.Ophthalmol 2003; 87: using ICG. Curr. Eye.Research 2004; 27:395-399.
216-219.
20. Kwok AKH, Li WWY et al. Indocyanine green staining
5. Enaida.H, Hisatomi.T, Goto.Y et al. Preclinical and removal of internal limiting membrane in macular
investigations of internal limiting membrane staining hole surgery: histology and outcome. Am.J.Ophthalmol
and peeling using intravitreal brilliant blue G. Retina 2001; 132: 178-183.
2006; 26: 623-630.
21. Maia.M, Kellner L, de Juan EJr et al. Effects of ICG
6. Ozawa.T, Britz GW et al. Bromophenol blue staining of delivery over the retinal surface and into the subretinal
tumors in a rat glioma model. Neurosurgery 2005; 57: space in rabbits. Retina 2004; 24: 80-91
1041- 1047.
22. Maia M, Margalit E et al. Effect of Intravitreal ICG
7. Haritoglou.C, Yu A, Freyer W et al. An evaluation of injection in rabbits. Retina.2004 : 24: 69-79
novel vital dyes for intraocular surgery. Invest
Ophthalmol Vis Sci 2005; 46: 3315-3322. 23. Jackson T.L, Hillenkamp J et al. Safety testing of ICG
and Trypan blue using retinal pigment epithelium and
8. SokolowskiJ, Engeset A. Toxic effect of patent blue on glial cell cultures. Invest Ophthalmol Vis Sci 2004; 45:
rat lymph node lymphocytes. Lymphology 1974; 7: 2778-2785.
28-31
24. Iriyama.A, Uchida.S. et al. Effect of ICG on retinal ganglion
9. Jonas JB, Kreissig I et al. Intravitreal Triamcinolone cells. Invest Ophthalmol Vis Sci 2004: 45: 943-947.
acetonide for treating intraocular exudative,
proliferative and neovascular diseases. Prog Retina Eye 25. HO. J, Tsai R J, Chen SN et al Toxic effects of ICG on
Res 2005; 24: 587-611. the RPE related to osmotic effects of the solvent. Am.J.
Ophthalmol 2003; 135-258.
10. Desmettre T, Devoiselle JM et al. Fluoresence properties
and metabolic features of ICG as related to angiography. 26. Ho JD, Tsai RJ, Chen SN, Chen HC. Removal of sodium
Surv Ophthalmol 2000; 45: 15-27. from the solvent reduces RPE toxicity caused by ICG:
implication for macular hole surgery. Br. J. Ophthalmol
11. Rodriguez EB, Meyer CH et al. Intravitreal staining of 2004;88:556-559.
ILM using ICG in the treatment of macular holes.
Ophthalmologica 2005; 219: 251-262. 27. Stalmans P, Van Aken EH et al. Toxic effect of ICG on
RPE related to osmotic effects of the solvent. Am.J.
Ophthalmol 2002; 134: 282-285

28. Lochhead J, Jones E, Chui D etal Outcome of ICG
assisted ILM peel in macular hole surgery. Eye 2004;
18: 804-808.

June 2008 M. Chakrabarti et al. - Vital Dyes 179

29. Slaughter.K, Lee IL Macular hole surgery with and 46. Guo S, Tutela AC, Wagner R, Caputo AR. A comparison
without ICG assistance. Eye 2004; 8;376-378 of the effectiveness of four biostains in enhancing
visualization of the vitreous. J Pediatr Ophthalmol
30. Rodrigues EB, Meyer CH Meta analysis of Strabismus 2006; 43:281-284.
chromovitrectomy with ICG in macular hole surgery.
Ophthalmologica 2007; 114: 587-590 47. Kozak I, Cheng L, Mendez T, et al. Evaluationof the
toxicity of subretinal triamcinolone acetonide in the
31. Meyer CH, Rodrigues . EB. et al A novel applicator for rabbit. Retina 2006; 26:811-817.
the selective painting of pre-retinal structures during
vitreo retinal surgery. Graefes Arch. Clin. Exp. 48. Yu SY, Damico FM, Viola F, et al. Retinal toxicity of
Ophthalmol 2005; 243: 487-489. intravitreal triamcinolone acetonide: a morphological
study. Retina 2006; 26:531-536.
32. Kodji Kian L, Richter T et al. Toxic effects of indocyanine
green and trypan blue on the retinal pigment 49. Morrison VL, Koh HJ, Cheng L, et al. Intravitreal toxicity
epithelium. Graefes Arch. Clin. Exp. Ophthalmol 2005; of the kenalog vehicle (benzyl alcohol) in rabbits. Retina
243: 917-925. 2006; 26:339-344.

33. La Heij EC, Dieudonne SC et al. Immuno histochemical 50. Narayanan R, Mungcal JK, Kenney MC, et al. Toxicity
analysis of the ILM peeled with indocyanine green. of triamcinolone acetonide on retinal neurosensory and
Am.J. Ophthalmol 2005; 140: 1123-1125. pigment epithelial cells. Invest Ophthalmol Vis Sci 2006;
47:722-728.
34. Rivett. K, Kruger L, Radloff S et al. Indocyanine green
assisted ILM peel in macular hole surgery: does it make 51. Sokolowski J, Engeset A. Toxic effect of patent blue violet
a difference? Graefes Arch. Clin.Exp.Ophthalmology on rat lymph node lymphocytes. Lymphology 1974;
2004; 242;393-396. 7:28-31.

35. Jackson, TL Vote B, Knight BC et al Safety testing of 52. Mennel S, Meyer CH, Tietjen A, et al. Patent blue: a
indocyanine green using retinal pigment epithelial and novel vital dye in vitreoretinal surgery. Ophthalmologica
glial cell cultures. Invest ophthalmol Vis Sci 2004; 45: 2006; 220:190-193.
3697-3703.
53. Luke C, Luke M, Sickel W, Schneider T. Effects of patent
36. Ullern.M, Roman S et al. Contribution of indocyanine blue on human retinal function. Graefes Arch Clin Exp
green to macular hole and epimacular membrane Ophthalmol 2006; 244:1188-1190.
surgery : preliminary study. J.Fr.Ophthalmol 2002; 25:
915- 920. 54. Westermeier R. Sensitive, quantitative, and fast
modifications for Coomassie blue staining of
37. Marmer MF Retinal Detachment from hypertonic polyacrylamide gels. Proteomics 2006; 6:61-64.
intravitreal injection. Invest Ophthalmol Vis Sci 1979;
18: 1237-1244. 55. Enaida H, Hisatomi T, Goto Y, et al. Preclilnial investigation
of internal limiting membrane staining and peeling using
38. Melles GR, de Waard PW, Pameyer JH, Houdijn Beekhuis intravitreal brilliant blue G. Retina 2006; 26:623-630.
W. Trypan blue capsule staining to visualize the
capsulorhexis in cataract surgery. J. Cataract Refract 56. Hisatomi T, Enaida H, Matsumoto H, et al. Staining
Surg 1999; 25 : 7-9. ability and biocompatibility of brilliant blue G:
preclinical study of brilliant blue G as an adjunct for
39. Veckeneer M, van Overdam K, Monzer J, et al. Ocular capsular staining. Arch Ophthalmol 2006; 124:514-519.
toxicity study of trypan blue injected into the vitreous
cavity of rabbit eyes. Graefes Arch Clin Exp Ophthalmol 57. Enaida H, Hisatomi T, Hata Y, et al. Brilliant blue G
2001; 239 : 698 – 704. selectively stains the internal limiting membrane/
brilliant blue G assisted membrane peeling. Retina
40. Vote BJ, Russell MK, Joondeph BC. Trypan blue – 2006; 26:631-635.
assisted vitrectomy. Retina 2004; 24 : 736 – 738.
58. Haritoglou C, Yu A, Freyer W, et al. An evaluation of
41. Luke C, Luke M, Dietlein TS, et al. Retinal tolerance to novel vital dyes for intraocular surgery. Invest
dyes. Br J Ophthalmol 2005; 89 : 1188 – 1191. Ophthalmol Vis Sci 2005; 46:3315-3322.

42. Jin Y, Uchida S, Yanagi Y, et al. Neurotoxic effects of 59. Schuettauf F, Haritoglou C, May CA, et al.
trypan blue on rat retinal ganglion cells. Exp Eye Res Administration of novel dyes for intraocular surgery:
2005; 81 : 395 – 400. an in vivo toxicity animal study. Invest Ophthalmol Vis
Sci 2006; 47:3573-3578.
43. Narayanan R, Kenney MC, Kamjoo S, et al. Trypan blue:
effect on retinal pigment epithelial and neurosensory 60. Haritoglou C, Tadayoni R, May CA, et al. Short-term in
retinal cells. Invest Ophthalmol Vis Sci 2005; 46 : vivo evaluation of novel vital dyes for intraocular
304-309. surgery. Retina 2006; 26:673-678.

44. Jackson TL, Kwan AS, Laidlaw AH, Aylward W. 61. Abrams GW, Topping T, Machemer R. An improved
Identification of retinal breaks using subretinal trypan method for practice vitrectomy. Arch Ophthalmol 1978;
blue injection. Ophthalmology 2006; Nov 20 [Epub 96:521-525.
ahead of print].
62. Hata Y, Enaida H, Sassa Y, et al. Preclinical investigation
45. Burk SE, Da Maa AP, Snyder ME, et al. Visualizing of fluorometholone acetate as a potential new adjuvant
vitreous using Kenalog suspension. J Cataract Refract during vitreous surgery. Graefes Arch Clin Exp
Surg 2003; 29 : 645 - 651. Ophthalmol 2006; Dec 21 [Epub ahead of pint].

180 Kerala Journal of Ophthalmology Vol. XX, No. 2

OPHTHALMIC
INSTRUMENTATION

Ultrasound Evaluation of the Posterior
Segment of the Eye – A Ready Reckoner

Dr. Mahesh G. MS DO DNB FRCSEd., Dr. A. Giridhar MS, Dr. Ramkumar DO, Dr. Alpesh Rajput DO

Ultrasound Principles Terminologies

Ultrasound is an acoustic wave that consists of an Linear amplification- is on a small range and can
oscillation of particles in a medium. Ophthalmic display minor differences in echo strength between two
ultrasound uses 8-10 MHz probes (1 MHz is 1000000 echo sources but the range of intensities that can be
cycles per second). Ultrasound used in other medical displayed is limited.
specialties uses 1-5 MHz. When the frequency decreases
the wave length increases and penetration increases. Logarithmic amplification- Large dynamic range
Longer wavelength also reduces the resolution. UBM can be displayed but the small differences between two
uses higher frequencies like 50-100MHz resulting in echo signals cannot be displayed.
less penetration and better resolution. Ultrasound wave
is propagated as a longitudinal wave of alternating S amplification – developed by Ossoinig – Combines
compressions and rarefactions of molecules. This wave the wide range of logarithmic amplifiers and great
can be refracted and reflected as light. It is the reflected sensitivity of linear amplifiers
wave or echo that is utilized in ultrasound evaluation.
It depends on the acoustic impedence of the media and Gain measured in decibels represents relative units of
the difference in acoustic impedence at an interface ultrasound intensity. By adjusting the gain,
called acoustic interface. Also the angle of incidence amplification of echo signals displayed in the screen
determines the amount of echo returning. Perpendicular can be changed. It is just like adjusting the volume of
incident waves produce maximum echoes. radio where we can control the signals received by the
radio. The higher the gain the greater the ability of the
Ophthalmic ultrasound uses a pulse echo system which machine to detect weaker signals. When gain is reduced
is a piezo electric element which undergoes mechanical only stronger echoes will be displayed.
vibration when stimulated by electrical energy
producing a longitudinal ultrasound wave. The parts Time gain compensation (TGC): To enhance
of ultrasound system include a pulser, transducer, weaker signals from deeper tissues. Allows selective
receiver and a display screen. Amplification plays an amplification of weaker distant echoes compared to
important role in ophthalmic ultrasound. It determines stronger nearer echoes.
the ability of the system to display range of echo
intensities. This dynamic range is displayed in units of Standardized echography: Combined use of
decibels. standardized A scan and contact B scan developed by
Ossoinig.
Giridhar Eye Institute. Ponneth temple Road. Kadavanthra. Kochi. 682020
E mail:[email protected] Indications for Ultrasound Examination

1. Posterior segment evaluation in the presence of

June 2008 Mahesh G et al. - Ultrasound Evaluation of Posterior Segment 181

Few classic ultrasound findings

Fig. 5. Dislocated cataractous crystalline lens. Lens capsule
is not intact. Point like and membrane like echoes are
present in the vitreous cavity. There will be mobility
of the lesion on eye movements.

Ultrasound findings in Diabetic retinopathy

Fig. 1. 10 MHz ophthalmic ultrasound B/A scan machine
with probes and display units

Fig. 2. Point like echoes in vitreous haemorrhage, membrane Fig. 6. Plenty of point like echoes in the vitreous cavity
like lesion in retinal detachment and mass like lesion suggestive of vitreous haemorrhage

Fig. 3. To differentiate RD and PVD. RD has 100% reflective Fig. 7. Vitreous haemorrhage with incomplete posterior
membranous echo with attachment to optic disc and vitreous detachment. There are multiple point like
reduced after movement. PVD has variable spike echoes in the gel.
height with good after movements and if complete
no attachment at the disc.

Fig. 4 (a & b) Shifting fluid in exudative retinal detachment. Fig. 8. Vitreous haemorrhage with schisis cavity inside and
The figure on the left shows membranous echo complete PVD. The after movements will be very good
inserting at the disc with high reflectivity and good in presence of complete PVD.
after movements. To the left is the same retinal
detachment in sitting position showing shifting fluid.
There is significant choroidal thickening and T sign.

182 Kerala Journal of Ophthalmology Vol. XX, No. 2

Fig. 9. Membranous echo attached to the disc which is Fig. 13.Two membranous attachment pulling the retina in a
incomplete PVD. There are point like echoes beneath tent like fashion. There is PVD between the TRD.
the membrane suggestive of subhyaloid haemorrhage.
Also there are multiple echoes in the pre-papillary
area due to adherent fibrous proliferation and
peripapillary tractional retinal detachment.

Fig. 10. Membranous echo inserting at the disc with Fig. 14. Multiple membranous lesions attaching to the disc
moderate after movements. This is PVD. There is area with vitreoschisis. There is subvitreal
point like echoes beneath this layer suggestive of haemorrhage as well as subretinal haemorrhage. In
sub vitreal or subhyaloid haemorrhage. the lower part there is retinal detachment.

Ultrasound findings in Trauma

Fig. 11. Membranous echo in the lower part with plenty of Fig. 15. High reflective (100% spike height) intraocular
point echoes beneath suggestive of Incomplete PVD foreign body with shadowing behind. Low gain
of lower part with sub vitreal haemorrhage. There examination will help in the better delineation.
is intragel haemorrhage also.

Fig. 12.Two membranous attachment pulling the retina in a Fig. 16. High reflective point like echo with shadowing
tent like fashion. This is tractional retinal detachment. suggestive of radio opaque retained intraocular
There is no PVD between the TRD along the arcades. foreign body. Also there is a shallow retinal
This is called table top TRD. detachment seen as membranous high reflective echo
with not much after movements.