November 2003

DOS TIMES TIM ES

Editor-in-chief Typical ring infiltrate in Acanthamoeba Keratitis (See page 208)
Dr. Jeewan S. Titiyal
CONTENTS
Associate Editors
Dr. Harish Pathak EDITORIAL ................................... 201 Body: Investigations .................. 225
Dr. Harminder K. Rai Lt. Col. V.S. Gurunadh, Col. D.P. Vats,
Dr. Vijay B. Wagh REVIEW Lt. Col. A Banarji, Lt. Col. M. Bhadauria

Editorial Advisers w Optic Neuritis ............................. 203 APPLIANCES
Dr. K.P.S. Malik Vimla Menon, Rohit Saxena,
Madhurjya Gogoi w Multifocal Electroretinogram
Dr. Pradeep Sharma - Practical Applications ............. 227
Dr. Ramanjeet Sihota w Acanthamoeba Keratitis ............ 211 Raj Vardhan Azad, Nikhil Pal,
M. Srinivasan YR Sharma, Atul Kumar
Dr. Ritu Arora
Dr. Dinesh Talwar CURRENT PRACTICE ART OF REFRACTION

Special Correspondents w Newer Ophthalmic Anaesthesia w Types of Frames and Spectacle
Dr. Ajay Aurora Techniques .................................. 208 Lenses ........................................... 230
N. G. Mandal, N.R. Biswas Monica Choudhry, Priyanka
Dr. Rajib Mukherjee Dhingra, Jeewan S. Titiyal
Dr. Anita Sethi w Role of Pre-Perimetric
Diagnosis in Glaucoma .............. 214 COLUMNS
Dr. Devender Sood Parul Sony
Dr. Pradeep Venkatesh w Letters to Editor .......................... 202
MANAGEMENT PEARLS w DOS Quiz No. 5 .......................... 233
Coordinators w Journal Abastract ........................ 234
Dr. Anurag w Secondary IOL Implantation .... 217 w Forthcoming Events ................... 238
Dr. Anand Ruchi Goel, KPS Malik
Dr. Madhusudan TEAR SHEET-5
Ms. Monica Choudhry w Management of Hypotony
Dr. Pranav D. More after Glaucoma Surgery ............ 223 w Surgical Management of
R.N. Bhatnagar, Sachin Walia, Refractive Errors ......................... 239
Published by Deepak Sharma Harish Pathak, Vijay B Wagh,
Dr. Jeewan S. Titiyal Harminder K Rai
w Retained Intraocular Foreign
for
Delhi Ophthalmological Society Keep April 3-4, 2004 Free for

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November, 2003 199 DOS Times - Vol.9, No.5

November, 2003 200 DOS Times - Vol.9, No.5

EDI- sight into the latest developments in lems.
various fields of ophthalmology In the end I would line to remind
DT eOar- friends, whether with regard to newer investi-
RIIALhave been gative tools, newer operative equip- our members the importance of DOS
ments as well as to approach complex — Rating Systems (Page 237) which
enthralled by situations in ophthalmology. I feel that has been introduced by our society
the roaring suc- the present trend should continue in keeping in mind the need to update
cess and the en- the future interactions too. ourselves to the rapidly changing
thusiastic re- knowledge in our field. This system
sponse of the This issue covers a mirage of top- encourages and recognizes the efforts
DOS Members ics, which we encounter in our day-to- made by our members not only to
at the Mid day practice like secondary IOL im- maintain a high academic standard but
Term Confer- plant ation, hypotony after glaucoma also to imbibe the new evolving prac-
ence, which took place at India Habi- surgery and how to approach a patient tical skills which will ultimately prove
tat Centre on 19th October, 2003. The with retained intraocular foreign body. beneficial in the treatment of our pa-
topics, which were chosen, had some The readers should read them and try tients.
unsolved controversies associated with to incorporate the relevant things into
them and it was our desire to hear from their clinical practice so as to have a Thanks,
the experts about their views on these better management approach for the
topics and to enlighten us fellow oph- patient who presents with these prob- Dr. Jeewan S. Titiyal
thalmologists about them. I think at the Secretary
end of sessions, all got a very fair in-

Programme for DOS Monthly Clinical Meeting for November

2003
Venue: Conference Hall, Dr. Shroff's Charity Eye Hospital, Daryaganj, New Delhi-2
Date & Time : 29th November, 2003 (Saturday) at 2.30 P.M.

Case Presentation 10 Mins.
10 Mins.
1. Living Pearl in the Anterior Chamber ............................................... Dr. Saman Adil

2. A case of Idiopathic Retinal Vasculitis, .............................................. Dr. Ajay Aurora
Aneurysms and Neuroretinitis

Clinical Talk
l Cataract Refractive Surgery ................................................................. Dr. Noshir M. Shroff 20 Mins.

Mini Symposium:
Practical tips of Managing Treatable Pediatric Ocular Disorders

Chair Persons: Dr.Bijayananda Patnaik, Prof. J.C Das, Prof S.Ghose and Dr.Cyrus M.Shroff

1. Pediatric Cataract .................................................................................. Dr. Suma Ganesh 10 Mins.
2. Pediatric Glaucoma ............................................................................... Dr. Suneeta Dubey 10 Mins.
3. Pediatric Retinal Detachment .............................................................. Dr. Ajay Aurora 10 Mins.
4. Retinopathy of Prematurity ................................................................. Dr. Neeraj Sanduja 10 Mins.
5. Hypovitaminosis A: are the policies correct? .................................... Dr. Sara Varughese 4 Mins.

Panel Discussions : 15 min.

November, 2003 201 DOS Times - Vol.9, No.5

Letters to Editor

Dear Dr. Titiyal, respositor and spread it along the which may not be required, and prob-
This letter gives my own views and whole corneoscleral incision and then ably causing some side effects with
in the A.C. It dissolves the vitreous, these, is not scientific in my opinion
also a rejoinder to the article "Cystoid hence there will be no incarceration and may lead one to the consumer
Macular Edema (CME) following of vitreous in the incision. Also when- courts. As regards topical steroids, we
cataract surgery" published in DOS ever. There is vitreous prolapse, I al- have already mentioned in our article,
bulletin of July 2003, by learned two ways put the patient on steroid tab- the beneficial role of topical steroids
authors. lets 8 per day in divided doses, for and topical NSAIDs in the routine
atleast three days and either after 3 post-operative care to decrease the in-
The article published in July, 2003 days or 4, 5 days I taper off. My these cidence of CME.
DOS bulletins advises wait and watch three extra steps perhaps prevent
policy during which authors advice CME and all such cases get 6/9 or 6/ The results of automated vitrec-
use of NSAIDs eye drops for 4 to 6 6 vision. tomy in managing vitreous loss are
weeks and if no improvement, then excellent. The surgeons having
to shift to steroids. But if the patient Dr. N.C. Shingal phacoemulsification machines have
does not get benefit in 4 to 6 weeks New Delhi a built in vitrectomy unit in their
time, he will soon shift else-where. phaco machines. For others, the lo-
And it is possible that irreversible wwww cally made vitrectomy units are rela-
changes may occur and even with Dear Sir, tively very cheap and work well for
steroids may not restore full vision. anterior vitrectomy in cases with vit-
One has to seriously think of wait and I thank you for taking interest in reous prolapse. I am sure, if one can
watch policy as it may land some one our article, Cystoid Macular Edema afford an operating microscope, he/
in a consumer court. Needless to say (CME) following cataract surgery. I she can also afford a simple Indian
that with use of steroids, I.O.P. had to would like to clarify a few doubts that Vitrectomy machine. I very strongly
be carefully watched. you have expressed in your letter. feel that before one learns and mas-
ters cataract surgery, one must learn
My policy in the use of steroid eye As most of the cases with CME re- to do a good anterior vitrectomy (to
drops is to taper off eye drops once solve on its own with good functional manage vitreous loss) and to give
benefit had been obtained by dilut- outcome, I still feel we must follow intravitreal injections (to manage
ing eye drops to 1 in 10, 1 in 15 and the step-wise approach as detailed in post-operative endophthalmitis). It is
finally 1 in 20 which is absolutely safe our article. I do not agree to over-treat- a myth that these techniques are dif-
and effective too. ing the patient just to ensure that he/ ficult and require a lot of experience.
she does not ‘shift elsewhere’. If one Both these techniques are much sim-
The authors of the article in July explains the nature of disease and the pler than cataract surgery and can
2003 have also stated that it is man- course of action properly to the pa- make a lot of difference in the out-
datory to have functioning auto- tients, they would understand and comes of cataract surgeries with com-
mated vitrectomy unit to deal with would be willing to ‘wait and watch’. plications.
vitreous prolapse. It is a very costly If the whole ophthalmic community
instruments, requires experience in follows the same scientifically ap- Dr. Vinay Garodia,
its use. I handle such cases with hylase proved guidelines, there should be MD, DNB, FRCS
as mention below. If there is vitreous no fear of patient shifting elsewhere
prolapse, I empty a hylase ampoule or even of the Consumer Courts. In Visitech Eye Hospital, Delhi.
in a small bottle, dip the tip of iris contrast, giving extra treatment,

Highlights for December Issue of DOS Times

Ø Management of Intra-operative Complications : Dr. A.K. Grover

Ø Ultrasound Biomicroscopy in Glaucoma : Dr. Tanuj Dada

Ø Phaconit: Current Prospective : Dr. Amar Agarwal
Ø Ophthalmic Viscosurgical Devices : Dr. Suresh Pandey
Ø Refractive Phakic IOLs : Dr. Namrata Sharma

November, 2003 202 DOS Times - Vol.9, No.5

REVIEW

Optic Neuritis phenomena called phos- Unlike optic neuritis, there
phenes are reported by is no leak on fluorescein an-
Vimla Menon MS, Rohit Saxena MD, some. Rarely, an increase in giography. A steadily pro-
Madhurjya Gogoi MD the visual defect or reduction gressing visual loss with
in visual acuity is seen with standard therapy is unusual
Introduction central vision which ranges exercise or increase in body in optic neuritis and raises
Optic neuritis is an acute, from mild reduction to no temperature (Uhthoff’s phe- the possibility of a compres-
light perception. It is most nomenon). The salient fea- sive or infiltrative optic neu-
inflammatory, immune me- commonly seen in young tures of typical and atypical ropathy. In this context, the
diated disorder of the optic adults (< 40 years), more of- optic neuritis are summa- visual fields not only provide
nerve characterized by sud- ten females, but no age is im- rized in Table 2. baseline value, but occasion-
den diminution in vision mune. A relative afferent pu- ally help to differentiate op-
usually in association with pillary defect (RAPD) in uni- In children, optic neuritis tic neuritis from other optic
periocular pain. It was first tends to be bilateral and si- neuropathies.
multaneous, is often associ-
Optic neuritis is an acute, inflamma- ated with viral infection, and Bilateral optic neuritis
tory, immune mediated disorder of the generally has a good prog- should be differentiated
nosis. Whereas in adults ret- from nutritional/toxic neu-
optic nerve characterized by sudden robulbar optic neuritis is ropathy, Leber’s hereditary
diminution in vision usually in associa- more common, papillitis is optic neuropathy, ischemic
more commonly seen in chil- optic neuropathy, func-
tion with periocular pain dren. It may be unilateral or tional, immune mediated
bilateral, and the long-term and Devic’s disease. Leber’s
described by Nettleship in lateral cases is seen in all outcome is favourable even optic neuropathy may show
1884. The etiology is un- cases. The optic nerve head without treatment. visual improvement, but
known in the majority of may show a papillitis, char- lack of pain, circum-papil-
cases, but this disorder is acterized by disc swelling, or The presumably normal lary telangiectatic
now considered a ‘Forme a normal disc in retrobulbar fellow eye may show defects microangiopathy, absence of
fruste’ of multiple sclerosis. neuritis. The presence of a in color vision, contrast sen- leak on fluorescin angiogra-
The pathogenesis is thought macular star is suggestive of sitivity, visual fields, and in phy as well as a maternal
to be demyelination of the neuroretinitis. A few poste- VER (Subclinical optic neu- inheritance pattern would
optic nerve, which may be rior vitreous cells are usual, ritis). Field defects may be point to the diagnosis. Hy-
either idiopathic, or associ- especially in front of the disc, seen in upto two thirds of fel-
ated with primary demyeli- but any extensive vitreous
nating disorders such as reaction requires investiga- A typical case of acute optic neuritis is
Multiple Sclerosis, Devic’s tion for an infective cause. characterized by sudden unilateral loss
disease, Schilder’s disease Retinal venous sheathing as- of central vision which ranges from mild
and encephalitis periaxialis sociated with optic neuritis
concentrica. Causes other indicates increased risk of reduction to no light perception
than primary demyelination developing multiple sclero-
are listed in Table 1. sis. low eyes (ONTT). The optic pertension retinopathy and
nerve head may show some
Clinical features Other features are loss of degree of pallor in cases of papilledema, unless in the
A typical case of acute op- colour vision, decreased con- previous attacks.
trast sensitivity, decreased chronic or atrophic stage, do
tic neuritis is characterized brightness sense and de- Differential diagnosis
by sudden unilateral loss of layed dark adaptation. Vi- The important differential not have visual loss and af-
sual field defects can vary
Dr. Rajendra Prasad Centre for from generalized depression diagnosis of unilateral optic ferent pupillary defect, and
Ophthalmic Sciences to any form of defect. Some neuritis is ischaemic optic
(AIIMS), Ansari Nagar, report seeing holes in their neuropathy, which presents would show signs related to
New Delhi-110029, India field called Swiss-cheese vi- with acute painless visual
sual field. Positive visual loss, and field changes that the underlying disease.
are usually altitudinal, and
unilateral pallid disc edema, Devic’s disease may initially
which may be segmental.
present as optic neuritis but

paraplegia follows.

Neuroimaging shows cavi-

tation in contradistinction to

the periventricular plaques

of multiple sclerosis. Optic

perineuritis and chronic op-

November, 2003 203 DOS Times - Vol.9, No.5

REVIEW

Table 1: Causes of optic neuritis other than demyeli- clinically and does not re- In cases of
nation
quire any investigations. In- neuroretinitis it is
vestigations are indicated in

1) Viral infections: Chicken pox, mumps, measles, CMV, atypical presentations such imperative to
Herpes zoster, infectious mononucleosis as neuroretinitis, bilateral have a detailed
optic neuritis, acute optic investigation to
2) Post viral syndrome neuritis in children, recur- diagnose any
rent optic neuritis, when the infective cause
3) Granulomatous inflammation: Tuberculosis, syphilis, history and clinical examina-
sarcoidosis tion suggest possible local / should include fat suppres-
systemic infection or inflam- sion sequences to show up
4) Spread from contiguous inflammation of the orbit, matory diseases, the disease the plaques of demyelination
meninges and sinuses does not follow a typical along the optic nerve and the
course (atypical). periventricular white mat-
5) Intraocular inflammation involving the retina, uvea ter, which enables the diag-
or sclera, Both CT Scan and MRI of
the brain and orbits are use-
6) Other immune mediated inflammation: SLE, Sjogren’s dis- ful for excluding compres-
ease

7) Others: As a Para infectious entity (Rare). Remote car-
cinomas

sive lesions, complemented nosis of multiple sclerosis

tic neuritis are both ex- (Poser’s criteria). However,

tremely rare, the latter being In children, optic neuritis tends to be even a normal MRI does not
a diagnosis of exclusion only. bilateral and simultaneous, is often preclude development of MS
at a later stage.

Others associated with viral infection, and In the appropriate setting,
In optic neuritis due to generally has a good prognosis. Whereas serology, immunological
tests and spinal CSF exami-
sarcoidosis, the vision im- in adults retrobulbar optic neuritis is nation are helpful. Where an
proves with steroid therapy,

but recurs on tapering it, more common, papillitis is more com- infective etiology is sus-
which is characteristic. This monly seen in children pected, serological tests for
feature is distinctly unusual syphilis (FTA-ABS, VDRL),

in demyelinating optic neu- toxoplasmosis (Immuno

ritis. Infective causes of op- by orbital ultrasonography. haem-agglutination), Lyme

tic neuritis rarely present in Investigations CT scan should ideally be disease, toxocariasis and
isolation. A typical case of acute thin section and contrast en- blood culture are advised.
hanced, whereas the MRI Viral serology and identifi-
Work-up of a patient optic neuritis is diagnosed
cation of viral nucleic

of optic neuritis Optic neuritis acid are not routinely
The history taking done. A chest X-ray

should note any symp- Typical Atypical is advised for pulmo-
toms of preceding vi- nary Koch’s and sar-

ral illness, exanthema, Monosymptomatic coidosis, and X-ray of
sinus disease, concur- the paranasal sinuses

rent viral illness in the Features of MS Optic Neuropathy for local sinus pathol-
family and sexually Yes No mimicking Optic neuritis ogy. The Mantoux
transmitted disease. test in endemic areas
Any neurological is useful mainly for
manifestation sugges- its negative value.

tive of multiple sclero- Optic neuritis in MS Optic neuritis in systemic Tests such as anti-
sis should be looked diseases other than MS nuclear antibody for
for. In cases of neurore- SLE may be useful
tinitis it is imperative where an immuno-

to have a detailed in- logical disease is sus-

vestigation to diag- Typical mono-symptomatic optic neuritis pected. Routine CSF

nose any infective examination for

cause. Fig. 1: Optic nerve head appearance in papillitis oligoclonal bands etc.

November, 2003 204 DOS Times - Vol.9, No.5

REVIEW

is not recommended. Screen- Table 2 : Features of typical and atypical optic neuritis
ing for HIV infection may be
indicated in selected cases. Parameters Typical Atypical
May be bilateral
Serum electrolytes and Eye involvement Unilateral
other routine investigations As for typical optic neuritis
are done to rule out any con- Visual acuity 5 Sudden loss
traindication for intravenous Pain Variable (mild loss-no light Not associated
high dose steroids. The VER perception) Outside 20 – 50 years.
shows delayed latency and Periocular pain, tenderness ± No gender predilection
reduced amplitude in the Aggravated by eye movement As for typical optic neuritis
acute phase, could also re-
veal subclinical involvement Age Commonly 20-40 yrs, can affect As for typical optic neuritis
of the fellow eye, and helps all ages l Worsening of visual
in the follow up. Sex Females more commonly affected
Other visual Diminished light intensity function beyond 2 wks
Treatment functions Loss of colour vision 6 l Lack of visual improvement
Corticosteroids have been Diminished contrast sensitivity 7
Reduced binocular depth and
the mainstay of treatment of motion perception (Pulfrich)
optic neuritis. They have
been used by the oral, retrob- Pupils RAPD in unilateral cases
ulbar and parenteral routes. Course Bilateral cases : RAPD difficult to elicit
In this context, the Optic Gradual deterioration over 2 weeks
Neuritis Treatment Trial Improvement over several weeks
(ONTT) was a landmark Return to normal/near normal levels

MRI should include fat suppression by oral prednisolone 1mg/ ery. Pulse intravenous Dex-
sequences to show up the plaques of kg/day for 11 days. Alterna- amethasone (3-5mg /kg /
demyelination along the optic nerve and tively 1gm of methyl-pred- day) 200mg once daily in 150
the periventricular white matter, which nisolone can be given intra- ml (1 pint) of 5% dextrose is
enables the diagnosis of multiple sclero- venously in a single dose for given over 1 hour for 3 days.
3 consecutive days on an out- Oral taper is not required.
sis (Poser’s criteria) patient basis. This also is to This equivalent dose of dex-
be followed by oral pred- amethasone is calculated on
study; it provided invaluable no known long-term benefit. nisone 1mg/kg/day for 11 the basis of the difference in
information on the clinical Witholding steroids alto- days, followed by short oral glucocorticoid potency be-
profile, natural history, and gether is therefore also a rea- taper over 3 days. The vital tween it and methylpred-
treatment measures and sonable option. functions should be moni- nisolone, which is generally
their outcomes (Table 3). tored, bearing in mind the taken as 5:1. However, whe-
Interferons have also evoked Indications for treatment known side effects of high ther this relation holds true
interest of late. for acute optic neuritis with
IV steroids is a visual acuity The Optic Neuritis Treatment Trial
Intravenous corticoster- <6/12, one eyed patient, bi- (ONTT) was a landmark study; it pro-
oids have been shown to has- lateral involvement, recur- vided invaluable information on the
ten visual recovery, an effect rent optic neuritis, and pedi-
that is seen within the first 2- atric patients. They may also clinical profile, natural history, and
3 weeks, maximum at be used to reduce the short treatment measures and their outcomes
around 6 weeks, but they of- term risk of CDMS, and if the
fer no long term benefit ex- patient requires early visual dose intravenous corticoster- in the high dose range is not
cept for a reduced risk of rehabilitation. oids. settled. The advantages of
CDMS in the first 2 years dexamethasone are that it is
(ONTT). Intravenous dex- The ONTT protocol However, at our Centre, easily available, more cost
amethasone in equivalent was pulse intravenous Me- we have found intravenous effective and possibly, safer,
doses also helps in hasten- thyl-prednisolone succinate dexamethasone to be as ef- with lesser side effects.
ing visual recovery, but with in the dose of 250mg QID for fective as methylpredniso-
3 consecutive days followed lone in terms of visual recov- In children the dose of me-

November, 2003 205 DOS Times - Vol.9, No.5

REVIEW no pediatric patients were
included. Slow oral steroid
Table 3: Salient features of ONTT taper is required since the
entity has been shown to be
The ONTT was a landmark clinical trial in the understanding of optic neuritis. It was steroid dependent, in addi-
multi-centric, randomized and involved 457 patients. The 5 years results and their tion to being steroid respon-
implications are summarized in table 3. The 10 year results are awaited. sive.

1. Megadose IV methyl prednisolone followed by oral steroids accelerated visual recov- In neuroretinitis, 50%
ery, but offered no long term benefit cases are presumed to be vi-
ral or idiopathic immune me-
2. ‘Standard dose’ oral prednisolone alone should not be used as diated, and the visual loss is
a) It does not improve visual outcome also determined, in addition
b) Associated with a higher incidence of recurrence to optic nerve inflammation,
by the macular involvement.
3. IV methyl prednisolone followed by oral steroids had a reduced risk of CDMS in the We institute pulse intrave-
first 2 years nous dexamethasone under
cover of antibiotics that are
4. Treatment was well tolerated with few major side effects started 2-3 days prior to ste-
5. Investigations like lumbar puncture, laboratory tests are not necessary for typical cases roid therapy. Prognosis is
6. Poorer visual outcome correlated with recurrent episodes, patients with CDMS and generally good. Treatment
for any underlying disease is
poorer vision at the time of enrolment. instituted at the same time.
7. Presence of brain MRI lesions is strongest predictor of developing multiple sclerosis
8. Neuroimaging is of limited value in establishing a diagnosis of optic neuritis The ONTT concluded that
9. MRI of the brain could be a good predictor of MS and could be used for making Oral prednisolone in standard

treatment decisions and prognostication.

Fig.2 : Sagittal section MRI of brain showing periventricular Table 4. Salient features of CHAMPS
plaques of demyelination in Multiple Sclerosis
CHAMPS (Controlled High Risk Subjects Avonex
Indications for treatment for acute optic Multiple Sclerosis Prevention Study)
neuritis with IV steroids is a visual
1) Conducted from 1996 to 2000, published in Septem-
acuity <6/12, one eyed patient, bilateral ber 2000
involvement, recurrent optic neuritis,
and pediatric patients 2) Randomized, multi-centric double blind, controlled
trial of 383 patients.
thyl prednisolone is 15- intravenously for 3 days.
30mg/kg/day for 3 days. However, the results of the 3) Included patients who had experienced a single acute
The dose of dexamethasone ONTT cannot be directly ex- clinical demyelinating event, including optic neuri-
is reduced to 50-100mg/day trapolated to children, since tis (50% of cases) and had evidence of demyelina-
tion on MRI

4) All patients received initial treatment with corticos-
teroids, and were randomly assigned to receive in-
jections of 30 mcg of interferon beta-1a (n=193) or
placebo injection (n= 190).

5) Results : The cumulative probability of developing
MS during the three year follow-up period was 35%
in the interferon group, and 50% in the placebo group
(p=0.002). The treatment group had a reduction in
the volume of brain lesions (p<0.001), fewer new or
enlarging lesions (p<0.001) and fewer gadolinium en-
hancing lesions (p<0.001) at 18 months.

6) Patients tolerated interferon treatment without sig-
nificant adverse effects.

7) A weekly dose of Avonex reduced the development
of multiple sclerosis in patients with lesions on MRI
at presentation

November, 2003 206 DOS Times - Vol.9, No.5

REVIEW

doses of 1-1.5 mg/kg/day should Table 5. Early treatment of Multiple Sclerosis Study tent of 75% in women and
not be used (Table1). How- Group 34% in men after 15-20 years
ever, one study reported a of the initial attack.
beneficial role of oral meth- · Interferon beta -1a in a dose of 22 mcg biweekly sub-
ylprednisolone in the dose of cutaneous injections The recent literature more
500mg daily for 5 days.1 strongly emphasizes the role
· 35% reduction in the rate of development of MS in the of a baseline MRI than did
Interferons group receiving interferon. the ONTT, especially with
Recent interest has fo- respect to the diagnosis of
temporally, is a common se- of MS over a 5-7 year follow MS, its treatment with inter-
cused on the prophylactic quelae. Visual recovery, in up after the onset of optic feron, and prognostication.
role of interferons in delay- the absence of recurrence, neuritis is approximately
ing the onset of CDMS 2 . Si- takes place within a few 30%. In the majority of cases, Summary
lent demyelination in the weeks but may continue for it develops within 7-years of Optic neuritis is typically
form of at least 2 clinically up to 1 year. The only pre- an attack of optic neuritis. In
silent brain lesions has been dictor of poor visual out- children optic neuritis is less characterized by acute visual
shown to be amenable to come in the ONTT was very commonly associated with loss with or without pain and
‘immunomodualting’ ther- low vision at study entry. MS (13-35%). The presence has a strong association with
apy, at least in the short term Even for those with no per- of neuroretinitis practically MS. The diagnosis is essen-
(CHAMPS)3 . The salient fea- ception of light at study en- rules out MS. tially clinical. Investigation
tures of the study are sum- try, 67% (20 of 30) recovered is warranted in atypical and
marized in table 4. Similar to 6/12 or better, and less MRI of the brain was recurrent cases. MRI is the
results have been reported than 10% had a final visual found to be the strongest single most useful investiga-
by the ETMSS4 group. It is acuity of <6/12. However, a prognostic indicator for MS tion for diagnosis and prog-
now held that patients rare patient may have severe in the ONTT. MS developed nosis, and its role is being
should be informed about persistent visual loss after a in 16% of patients with nor- expanded. Any case of neu-
the relationship between single attack. mal MRI, 37% with one or roretinitis must be investi-
optic neuritis and multiple two lesions and 51% in pa- gated aggressively to diag-
sclerosis, and the manage- Bilateral optic neuritis in tients with more than 2 le- nose an infective etiology.
ment options and prognosis adults is seen in approxi- sions. In patients with mono- The treatment of optic neu-
discussed. mately 30 % of cases, and is symptomatic optic neuritis ritis is essentially by intrave-
more common in multiple and a normal MRI, the risk nous megadose steroids that
Visual Prognosis sclerosis, as are recurrent at- of MS is thought to be low accelerate visual recovery,
Prognosis for visual re- but with no long-term ben-
We have found intravenous dexametha- efit. While the visual prog-
covery from an episode of sone to be as effective as methylpred- nosis is good, the neurologi-
typical optic neuritis is good, nisolone in terms of visual recovery cal prognosis is less so. The
but residual defects are usu- use of oral steroids in stan-
ally seen, more so after re- tacks, that may involve the and is quoted as 5-16% after dard doses should be
current attacks. The natural same or the other eye. The 5 years. If the brain MRI avoided.
history is to worsen over sev- incidence of recurrence var- shows T2 weighted lesions
eral days to 2 weeks and then ies from 11.3-24%; it was 20% after a first attack of isolated References
to improve, even without within 5-years in the ONTT. optic neuritis, the risk of
treatment. The ONTT found Neuroretinitis is a self-lim- CDMS is 30-65%. Optic 1. Sellebjerg F, Neilsen HS,
that among patients who re- ited disease, and recurrences nerve lesions that are larger Frederiksen JL, Olesen J. A ran-
ceived placebo 79% began to and involvement of the fel- and more posteriorly located domized controlled trial of oral
improve within 3 weeks of low eye are uncommon. In are more likely to be associ- high dose methyl prednisolone in
onset and 93% within 5 children visual recovery is ated with incomplete visual acute optic neuritis. Neurology
weeks. More than 97% of pa- good especially if the age at recovery. Females are possi- 1999;52:1479-1484
tients eventually recovered presentation is below 6 years, bly more predisposed to the 2. Clinically definite multiple
visual acuity upto 6/12. But, and the MRI is normal. eventual development of sclerosis
residual defects of colour vi- multiple sclerosis, and the 3. Controlled High Risk Subjects
sion, contrast sensitivity, ste- Neurological prognosis risk increases with the dura- Avonex Multiple Sclerosis Pre-
reopsis, visual fields VER. The risk of development tion of follow up, to the ex- vention Study
and RAPD may persist. Op- 4. Early treatment of Multiple
tic disc pallor, especially Sclerosis Study Group
5. Snellen , ETDRS
6. Ishihara / Farnsworth –
Munsell 100 hue test
7. Pelli-Robson

November, 2003 207 DOS Times - Vol.9, No.5

CURRENT PRACTICE

Newer Ophthalmic Anaesthesia Techniques

N. G. Mandal* MD, N.R. Biswas** MD, DM, DNB

Introduction management significantly sured and should be asked 25 mm needle is used. This is
Ophthalmic surgery is
contributes to the outcome of to remain silent. Somebody to minimize the risk of bleed-
usually minimally invasive,
enabling most of the proce- ophthalmic surgery. Thus, to hold the patient’s hand ing, perforation of the globe
dures to be performed as
day-care surgery despite every patient requires a throughout would be help- and complications of
high co-morbidity especially
among the elderly patients. proper preanaesthetic evalu- ful. A right angle screen can intraconal injection.
Local anaesthesia is associ-
ated with low morbidity ation with history, examina- be used to keep the drapes The conjunctiva is anaes-
with little disruption to daily
routine. Although general tion and relevant investiga- away from the patient’s face thetized with topical local
anaesthesia can be used
safely, many procedures tions. A careful anaesthetic and to support an oxygen anaesthetic drops (usually
such as cataract extraction,
trabeculectomy, lid surgery plan should be made on the and or air delivery system. 0.4% oxybuprocaine, 0.5%
or even retinal detachment
surgery can be performed Local anaesthesia is associated with proparacaine or 1.0% ame-
under regional anaesthesia thocaine) applied three times
or topical anaesthesia with
or without minimal sedation low morbidity with little disruption to at 1 minute intervals.
and analgesia. Nowadays The needle is advanced
about 86% of ophthalmic daily routine through the inferior fornix of
procedures in the UK are
performed under local ana- the anaesthetized conjunc-
esthesia. Locall anaesthesia
for eye surgery has changed basis of preoperative assess- A high flow of oxygen and tiva while the patient is
considerably over the past
few years. Alternatives to ment. The proposed proce- air increases the FiO2 and asked to look straight ahead
retrobulbar block and intro-
duction of newer local anaes- dure must be explained to prevents CO2 accumulation. at the neutral gaze position.
thetic agents have reduced
the number of complications the patient in a stepwise fash- This infratemporal injection
without detriment to effi-
cacy. This article will briefly ion. Elderly patients must be Anaesthesia Techniques is made through the conjunc-
discuss the local anaesthetic
techniques commonly used psychologically suitable and Peribulbar Block tiva midway between the
in modern day ophthalmic
practice. must have adequate cardio- Described by Davis and lateral canthus and the

Preoperative Assessment respiratory function to en- Mandel in 1986, it is widely saggital plane of the lateral
Preoperative anaesthetic
able them to stay supine used and the most popular limbus. The needle is always
* Consultant in Anaesthesia,
Peterborough Hospitals NHS during the operation. Pa- technique of regional anaes- kept tangential to the globe
Trust, Peterborough, UK
**Dr. R.P. Centre, tients should continue their thesia in eye surgery. It has and parallel to the orbital
AIIMS, New Delhi- 110 029.
regular medication. Routine largely replaced retrobulbar floor. There is no need to

premedication with a seda- block and general anaesthe- apply pressure on the sy-

tive is unnecessary. Allow- sia for many types of eye ringe as it will advance with-

ing patients to empty their surgery. Compared to ret- out resistance. When the

bladder before coming to robulbar block it is associ- needle tip is judged to be past

theatre is helpful. ated with lower risks of seri- the equator of the globe, the

ous complications. direction is changed to point

Intraoperative Patient Care Peribulbar block can be slightly medial (200) and

Patients should be moni-

tored by attaching ECG, The addition of hyaluronidase

pulse oximeter and a non- (3.75-7.5 iu/ml) helps to spread the local
invasive blood pressure de-

vice. They must be made anaesthetics to the apex and all

comfortable on the table. An compartments of the eye through the
intravenous access is estab- network of orbital connective tissue
lished to allow immediate

venous access. The anaesthe-

tistcandomuchtoallayanxi- performed in various ways. cephalad (100 upward) to

ety but if sedation is neces- It is commonly achieved by avoid the bony orbital mar-

sary, a small dose of intrave- double injection technique gin. The needle is advanced

nous midazolam can be through the conjunctiva. up to the hub. At this point 5

given. Patients must be reas- Usually, a 25G short-beveled ml of the local anaesthetic

November, 2003 208 DOS Times - Vol.9, No.5

CURRENT PRACTICE

Described by Stevens in 1992, sub- if the injectate is prewarmed depth of less than 1 mm. The
needle is then shifted medi-
Tenon’s infiltration for intraocular sur- to 370 C. ally, displacing the carun-
An indwelling catheter cula medially away from the
globe. The needle is ad-
gery has been established as a safe and can be introduced into the vanced in an anteroposterior
direction with the globe di-
effective technique extraconal space and local rected slightly medially by
anaesthetic agents can be the needle until a ‘click’ is
felt. At this moment the globe
mixtureisinjectedslowlyfol- not be blocked completely administered continuously comes back to the primary
gaze position. This ‘click’ is
lowing negative aspiration. and slight light perception or intermittently for long- normally heard at a depth of
15-20 mm when the needle
No resistance is normally will therefore remain. How- lasting ophthalmic surgery passes through the ‘medial
check’ ligament. At this point
encountered while injecting. ever, patients are unable to or post operative analgesia. the local anaesthetic mixture
is injected slowly. Orbital
If any resistance is felt then see the operation. In case of Most complications are compression can be applied
similar to peribulbar block.
the tip of the needle should an unsatisfactory block, observed within 15-20 min-
This technique is less
be repositioned. During the supplemental injections may utes of injection. The re- painful and it is associated
with less risk of haemor-
injection the lower eyelid be needed. ported complications related rhage and globe perforation.
It can provide better akine-
may fill with local anaes- Commonly used local to this technique are vasova- sia than peribulbar block.
However, corneal oedema,
thetic mixture and there may anaesthetic agents are 2% gal syncope, oculocardiac persistant chemosis and
medial rectus damage may
be some conjunctival lidocaine or 0.5 - 0.75% bupi- reflex, intravascular injec- occur.

oedema. vacaine. Newer agents like tion, local anaesthetic toxic- Sub-Tenon’s (Episcleral)
Block
A second injection can be l-bupivacane and ropi- ity, anaphylaxis, central
Described by Stevens in
made just medial to the me- vacaine are safer alternatives spread of local anaesthetics 1992, sub-Tenon’s infiltra-
tion for intraocular surgery
dial caruncule. For the me- to bupivacaine. Ropivacaine (e.g. brainstem anaesthesia), has been established as a safe
and effective technique. It
dial injection, the needle 1% with hyaluronidase in optic nerve damage, scleral has been used in cataract
surgery, pan-photocoagula-
traverses the tough canthal tion, vitreoretinal surgery
and even squint surgery.
ligament and may require Centbucridine, a newer local This procedure is more inva-
sive and requires instru-
firm gentle pressure. This anaesthetic agent has been ments including forceps,
may cause the eye to be found to provide longer surface scissors and lid spatulum.
pulled medially briefly. The
Insertion of blunt subte-
needle is passed into the or- analgesia than lidocaine non cannula is painless in
bit parallel to the medial or- majority of cases and highly
acceptable to the patients
bital wall until it reaches the peribulbar block is better penetration & perforation, and surgeons. This technique
avoids the passage of a sharp
hub. After negative aspira- than 0.75% bupivacaine for haemorrhage and retrobul- needle into the orbit, thus
avoiding needle related com-
tion another 5 ml of local lowering intraocular pres- bar haematoma, myopathy

anaesthetic mixture is in- sure in intraocular surgery. of the extraocular muscles &

jected slowly. Thiscouldbeduetothevaso- extraocular palsy and sub-

Following orbital injec- constrictive effect of conjunctival oedema. Pulsa-

tion, gentle digital pressure ropivacaine. tile ocular blood flow is de-

and massage over the closed The addition of hyalu- creasedfollowingperibulbar

eyelid help to disperse the ronidase (3.75-7.5 iu/ml) (as well as retrobulbar) block

anaesthetic and reduce in- helps to spread the local without any significant in-

traocular pressure. A com- anaesthetics to the apex and crease in intraocular pres-

pression device, oculopre- all compartments of the eye sure. It is not clear whether

ssor (Macintyre weight) or through the network of or- this is a significant risk fac-

Honan’s balloon will facili- bital connective tissue. Low tor for ocular ischaemia.

tate the spread of local an- concentrationofepinephrine

aesthetic solution and (1:200,000 to 1:400,000) Periocular Anaesthesia

achieve periorbital muscle mixed with the local A single injection at the

akinesia in 10-20 minutes. anaesthetics will minimize medial canthus is an alterna-

The pressure exerted by this the bleeding and prolong the tive technique to classic

device should not be greater duration of block. The qual- double injection peribulbar

than 30 mm Hg. ity of block has been reported anaesthesia.

Ptosis, akinesia and in- to improve with other adju- A 25G short bevel needle

ability to close the eye fully vants like clonidine or mor- is inserted in the semilunaris

are the signs of a successful phine. Patients comfort dur- fold, between the globe and

block. The optic nerve may ing the injection is increased the caruncula lacrimali to a

November, 2003 209 DOS Times - Vol.9, No.5

CURRENT PRACTICE

plications of intraorbital The addition of patient controlled anal- many ophthalmic proce-
structures. gesia (PCA) with fentanyl can provide dures performed under lo-
better analgesia, comfort and satisfac- cal anaesthesia much safer.
After establishing surface tion during cataract surgery performed Avoidance of general anaes-
anaesthesia and cleaning the thesia, early ambulation and
conjunctiva with 4% provi- with surface (topical) anaesthesia quick discharge from hospi-
done iodine solution, a small tal following local anaesthe-
incision is made in the lim- nique using phacoemulsi- vative-free 1% lidocaine is sia have contributed signifi-
bal conjunctiva inferomedi- fication there is no longer a well tolerated by the corneal cantly to reduce the mortal-
ally. A special curved 19G – need for complete akinesia endothelium, but higher con- ity, morbidity as well as cost.
22G blunt tipped cannula or absence of lid movement. centration is toxic. However,
connected to a 5 ml syringe Thus, the main goal of a lo- the quality of analgesia and Further Reading
containing a mixture of local cal anaesthetic technique is akinesia may not be opti-
anaesthetic (usually 2.0% to make the surgery pain- mum with this technique. 1. Aydin ON, Kir E, Ozkan SB,
lidocaine or 0.5-0.75% bupi- free. This can easily be Gursoy F. Patient-controlled
vacaine) is introduced pos- achieved with topical anaes- Sedation Technique analgesia and sedation with
teriorly along the surface of thesia in many patients. Carefully administered fentanyl in phacoemulsi-
the sclera towards both the 1 However, good cooperation fication under topical anaes-
and 2 o’clock directions un- from the patient is essential supplemental intravenous thesia. J Cataract Refract Surg
der Tenon’s capsule to its for this technique to be suc- analgesics and or sedatives 2002; 28: 1968-72
fullest extent. A slow injec- cessful. can greatly improve the sur-
tion of 1-4 ml of local anaes- gical condition and satisfac- 2. Bardocci A, Lofoco G,
thetic mixture is made in the Deep fornix block anaes- tion. Ultrashort acting opio- Perdicaro S, Ciucci F, Manna
equator of the globe to estab- thesia can be performed with ids like remifentanyl and L. Lidocaine 2% gel versus
lish surgical anaesthesia in 10 the placement of a sponge intravenous anaesthetics like lidocaine 4% unpreserved
minutes. A compression de- soaked with 0.5% bupiva- propofol are useful drugs in drops for topical anesthesia in
vice can be applied for 5 min- caine deep into the conjunc- this respect. Remifentanyl cataract surgery: a rando-
utes after performing the tival fornices for 15 minutes. 0.3mcg/kg can be used to mized controlled trial. Oph-
block. Four quadrant sub- It is a useful needle- free ana- provide short lasting analge- thalmology 2003; 110: 144-9
Tenon’s block has been used esthesia technique in pa- sia. Propofol in small 10-20
in many vitrioretinal sur- tients undergoing cataract mg incremental doses is use- 3. Bellucci R. Topical anaesthe-
gery. surgery using phacoemul- ful to provide sedation. The sia for small incision cataract
sification. key to good sedation is to surgery. Dev Ophthalmol
The risk of CNS spread, maintain verbal contact with 2002; 34: 1-12
optic nerve damage and glo- Newer preparation of 2% the patient. Oversedation
bal puncture is minimal with lidocaine gel was found to be can easily turn a cooperative 4. Biswas NR, Verma B, Ghose S,
the technique. However, it is more effective than 4% patient uncooperative due to Das GK, Beri S,Pandey RM.
more likely to cause superfi- lidocaine unpreserved drops confusion and airway prob- Centbucridine, a newer topi-
cial haemorrhage, chemosis for cataract surgery. Lidoc- lems. The addition of patient cal anaesthetic compared with
and rectus muscle trauma. aine gel provides better an- controlled analgesia (PCA) lognocaine: a randomized
Akinesia with sub-Tenon’s algesia & patient cooperation with fentanyl can provide double masked single drop
block may not be satisfac- and requires less intraopera- better analgesia, comfort and instillation clinical trial. Indian
tory. Orbital cellulitis has tive supplemental anaesthe- satisfaction during cataract J Physiol Pharmacol 2003; 47:
been reported after sub- sia. Centbucridine, a newer surgery performed with sur- 67-74
Tenon’s block. local anaesthetic agent has face (topical) anaesthesia.
been found to provide longer 5. Guise PA. Sub-Tenon anesthe-
Surface Anaesthesia surface analgesia than Phacoemulsification has sia: a prospective study of
Topical anaesthesia can be lidocaine. also been performed under 6,000 blocks. Anesthesiology
no anaesthesia. However, 2003; 98: 964-8
used alone or in conjunction Intracameral Anaesthesia this is unsuitable for many
with preservative free Intracameral lidocaine patients as well as surgeons. 6. Kubitz JC, Motsch J. Eye sur-
intracameral anaesthetic. It gery in the elderly. Best Pract
is a very effective form of 1%, supplemented with topi- Conclusion Res Clin Anaesthesiol 2003; 17:
anaesthesia for many in- cal anaesthesia is an alterna- Technical advancements 245-57
traocular surgery especially tive to retrobulbar block for
cataract extraction. With the phacotrabeculctomy. Preser- and newer drugs have made 7. The Royal College of
advent of small incision tech- Anaesthetists and The Royal
College of Ophthalmologists.
Local Anaesthesia for In-
traocular Surgery Guidelines.
July 2001, London, UK.

8. Laszlo CJ, Gombos K, Vimlati
L, Salacz G, Hatvani I. A cath-
eter technique in ophthalmic
regional anaesthesia – Ca-
daver experiments. Acta
Anaesthesiol Scand 2000; 44:
450-2

November, 2003 210 DOS Times - Vol.9, No.5

REVIEW

Acanthamoeba Keratitis who develop radial
keratoneuritis which is con-

sidered as pathognomic sign

M. Srinivasan MS may experience severe pain
due to neuritis. The corneal

lesion is insidious in onset,

Acanthamoeba Keratitis The first two are freque- cause keratitis. slowly progressive, runs for

is not uncommon in India. It ntly reported but A. culber- Sharma S et al have several weeks before final

forms 1-3% of suppurative tsoni is rare but highly viru- reported the incidence of diagnosis and the patient

keratitis. The incidence is lent. Acanthamoeba keratitis as would have had treatment

gradually on the rise due to one case among 4967 corneal

increased awareness and Predisposing factors ulcers associated with con- About 45% of cases
improved diagnostic facili- As in any other suppu- tact lens wear in India 5 are treated as fun-
ties. It was first recognized gal keratitis before
in 1973 and subsequently rative keratitis trauma to the Clinical features
cornea is the commonest

reported in 1974. It was cause and it comprises about In a large series reported final diagnosis
found to be sporadic till late 60% in developing coun- recently by us2 (culture

1980’s. First case of tries. In industrialized na- proved cases) the authors

Acanthamoeba castellani tions contact lens wear was have noticed the symptoms from two to three ophthal-

keratitis from India was re- found to be the frequent as- same as in other forms of mologists before the final

ported in 1986 by us. sociation in about 83% of suppurative keratitis either correct diagnosis. The pa-

cases of Acanthamoeba bacterial or fungal. The pain tients are imm-

Morphology keratitis. The predisposing out of proportion to the size unocompetent, affects males

Acanthamoeba is a free frequently than females in

living amoeboid, protozoan, Acanthamoeba is a free living India for obvious reason that

ubiquitous in nature and amoeboid, protozoan, ubiquitous men do lot of outdoor man-
found in air, soil and all wa- in nature and found in air, soil ual work than women and
ter sources. Also commonly the risk of ocular trauma is

found in upper respiratory and all water sources many fold in men. In contact
tract. It exists in two forms; lens wearers it affects young

1. Trophozoite or risk factor is unknown in of the ulcer reported freque- adults and involves both

2. Cystic form about 30-35% cases. ntly in Western ophthalmic sexes equally. Rarely sclera

The trophozoite mea- Acanthamoeba species literature is not reported in also may get involved.

sures about 25-40 µm and may rarely cause meningo- India. Probably patients About 45% of cases are

cyst about 15-25 µm. The encephalitis as well as having contact lens related treated as fungal keratitis

cyst may remain dormant granulomatous infection in Acanthamoeba keratitis before final diagnosis.

for several years. 30 species non-ocular tissues which Trauma to the cornea is the commonest
of Acanthamoeba have been occurs in immunocompro-

identified and at least 8 spe- mised hosts. Other amoebae cause and it comprises about 60% in
developing countries
cies cause keratitis. such as Hartmanella spp.

1. A. castellani and Naeglaeria spp. rarely

2. A. polyphagia

3. A. hatcheter

4. A. culbertsoni

5. A. rhysodes

6. A. griffin

7. A. lugdenesis

8. A. quina

Chief, Cornea Services & Fig.1a & 1b: Typical ring infiltrate
Chief Medical Officer
Aravind Eye Hospital & PG
Institute of Ophthalmology
No.1 Anna Nagar,
Madurai 625 020, Tamilnadu

November, 2003 211 DOS Times - Vol.9, No.5

REVIEW

Fig.2a: KOH wet mount Fig.2b: Gram stain Fig.2c: Lactophenol cotton blue

Clinical Characteristics of Acanthamoeba Keratitis Among these group of drugs, 0.1% pro-
pamidine isothionate (Brolene) and
In India Europe & USA
polyhexamethylene biguanide (PHMB)
Stromal ring 50% 29% are frequently used
infiltrate
2% 22% (the without hypopyon. E.coli overlay. It could be
Radial diagnostic sign) 5. History of topical an- kept at 250C and 300C. Some
keratoneuritis not the Frequently reported species do not grow at
diagnostic tibiotics, antifungals and higher temperature. The in-
Pain out of symptom 85% (CL related) antiviral as single therapy or oculated plate should be ob-
proportion 60% in combination for several served for 2 weeks before
29% weeks reporting as culture nega-
Trauma with not reported tive. The trophozoites are
organic matter 6. History of contact lens seen through the light mi-
wear croscope at mounted culture
Decreased corneal plate under low power.
sensation A high index of suspi-
cion: differentiating from Treatment of Acantha-
(Fig.1a, Fig.1b) lowing: Herpetic keratitis and fun- moeba Keratitis
1. History of trauma gal keratitis is the key to
Clinical features observed make correct diagnosis. Early appropriate treat-
in Indian series with organic matter, water ment makes the difference
source and rarely contact Laboratory diagnosis in the final visual outcome.
Epithelial defect - 74% lens wear Early diagnosis is crucial It has been reported that
medical treatment with
Corneal edema - 66% 2. Rural: adults in- to have better visual out- cysticidal drug could cure
volved in agriculture or come. But unfortunately it is the disease in 85% of cases
Diffuse infiltration - 62% manual labour always delayed due to vari- with better visual results.
able clinical presentation. Acanthamoeba species are
Ring infiltrate - 50% 3. Several consultations highly resistant to most of
with different eye care Smears: Scraping material the recommended drugs. In
Hypopyon - 41% personnel stained with Gram stain, Gi- vitro susceptibility testing
emsa, Calcoflour White yie- does not correlate with in
Satellite lesion - 18% 4. Necrotic corneal epi- lds positive results in about vivo activity.
thelium with ill-defined bor- 67 to 87% of cases. 10% KOH
Endothelial plaque - 6% ders as appear in a case get- wet mount also gives posi- In our country due to de-
ting topical anaesthetic tive result in 83% of cases. lay in diagnosis and treat-
Radial keratoneuritis- 2% drops for several minutes Basic gram stain and KOH ment, the visual results are
for minor procedures. Stro- wet mount will give an idea always poor to the level of
Dendrites - 2% mal ring infiltrate at midpe- in most of the cases to begin social blindness. The drugs
riphery of cornea with or the therapy. (Fig.2a, 2b, 2c) used for Acanthamoeba
The clinical diagnosis of keratitis could be classified
Acanthamoeba keratitis can Culture: Corneal infiltra-
be made based on the fol- tion material is plated on the
culture medium containing
Keratitis trauma to the cornea is the 1.5% non-nutrient agar with
commonest cause and it comprises about

60% in developing countries

November, 2003 212 DOS Times - Vol.9, No.5

REVIEW

Corticosteroid in
any form is

contraindicated

Surgical treatment

More than 80% of eyes in-

fected with Acanthamoeba

heal with medical therapy

alone. Surgical treatment is

delayed to avoid recurrence

Fig.3a & 3b: Vascularisation with PHMB of infection. Therapeutic

keratoplasty is rarely perfor-

Since the cysts in the corneal stroma vascularization disappears, med unless the eye shows
lies dormant for even an year it is when the drug is stopped. signs of perforation due to
better to try optical graft one year Patient tolerance is found delayed presentation. Since
and no adverse events are the cysts in the corneal

after complete healing noticed in spite of prolonged stroma lies dormant for even

application (Fig.3a,3b). an year it is better to try op-

under five groups; longed, runs for 3-12 Chlorhexidine as 0.02% tical graft one year after

1. Aromatic diamidines months. The median treat- topical drops also shows complete healing. Surgery

(0.1% propamidine iso- ment duration was 90 days equally good results. 1% for secondary glaucoma

thionate) in our study. clotrimazole (Auroclot. may be needed in few cases.

2. Aminoglycosides (neom- PHMB: It is used as 0.02% Aurolab, Madurai) could be

ycin) drops topically (diluted 1000 Gram stain, Giemsa. Stain and
Calcoflour white yields positive
3. Imidazole and triazole times from 20% parent solu-

antifungals tion with saline or sterile

4. Polymyxins water). The frequency of ap- results in about 67 to 87% of cases

5. Cationic antiseptics plication could be every

(PHMB ; chlorhexidine) hour first week; then ta- used as an adjuvant therapy. Suggested readings

Among these group of pered slowly based on the Cycloplegics and oral pain 1. Albert and Jakobiec. Prin-

drugs, 0.1% propamidine response to therapy. killers are used along with ciples and practice of Ophtha-
isothionate (Brolene) and Even without the deter- topical therapy. Corticos- lmology. 2nd edition. Vol.2
polyhexamethylene bigua- teroid in any form is con- page 920-923. W.B. Saunders
nide (PHMB) are frequently gent in cosmocil (PHMB) traindicated. Company
used. The treatment is pro- vascularization of the cornea 2. M. Srinivasan et al. Non-con-
is the major side effect. The tact lens related Acantha-

moeba Keratitis at a tertiary

Attention DOS Members centre in South India:
Implications for eye care
programmes in the region.

Med. Sci Monit, 2003; 9(4):CR

The Hi-tech DOS Library has started functioning on Ground Floor, 125-129.
3. Sharma S. et al. Patient chara-

Dr. R.P. Centre, Delhi Ophthalmic Sciences, AIIMS, New Delhi-110029 cteristics, diagnosis and treat-
from 12.00 Noon to 9.00 P.M. on week days and 10.00 A.M. - 1.00 P.M. ment of non-contact lens re-
lated Acanthamoeba Kera-

on Saturday, Sunday. The Library will remain closed on Gazetted Holi- titis. Br J Ophthalmol 2000:
84:1103-1108.

days. Members are requested to utilise the facilities available i.e. Com- 4. Epidemiology of eye dis-
puter, Video Viewing, Latest Books and Journals. We are planning to eases. 2nd edition, Prof.
Gorden Johnson. Arnold

subscribe two journals. Member can give suggestion in this regard. publication.
5. Sharma, Savitri et al. Trends

Dr. Lalit Verma in contact lens-associated mi-
Library Officer, DOS crobial keratitis in Southern
India. Ophthalmology 2003:

110(1):138-143.

November, 2003 213 DOS Times - Vol.9, No.5

CURRENT PRACTICE

Role of Pre-Perimetric Diagnosis in Glaucoma

Parul Sony MD

Glaucoma is a disease sion with certainty. Now uses yellow background and deficits, and these deficits
where the optic nerve head
changes and the visual field days everyone is concerned blue stimulus to selectively can be regarded as early in-
loss that generally occurs, is
irreversible. The commonly about early detection of the stimulate the blue cones, and dicators of glaucomatous
accepted parameters that are
used for the glaucoma diag- disease process so that a di- bleach the red and yellow damage. As SWAP helps to
nosis are raised intraocular
pressure (IOP), visual field agnosis is made before ap- cones. SWAP is said to de- detect these changes it may
defects (VFD) on white on
white perimetry (WOW), pearance of any irreversible tect the glaucomatous VFD help to predict which pa-
and optic disc changes. It is a
well established fact that loss. The upcoming tech- earlier than WOW perim- tients are at higher risk of
50% of the patients have an
IOP within normal range at nologies and newer diagnos- etry. Abnormalities detected developing glaucoma.
the time of presentation, and
VFD defects are picked up tic modalities may enable us by SWAP in patients with The major drawback with
by standard automated pe-
rimetry (SAP) when an irre- to make a pre-perimetric di- early glaucoma are typically SWAP is that it takes about
versible loss of 50 % retinal
nerve fibre layer has already agnosisofglaucomaandpre- larger than the correspond- 15% longer time than SAP
occurred. Thus in most of the
cases when a confirmative and is tiring and difficult for
diagnosis of glaucoma is es-
tablished, the eye has al- Visual field defects are picked up by the patient. SWAP also re-
ready had some irreversible standard automated perimetry (SAP) quires three baseline fields
changes, owing to the dis- like SAP. Another problem
ease. Similarly another im-
portant aspect in glaucoma when an irreversible loss of 50 % retinal is that cataract causes a sig-
patient is establishing the
progression of disease pro- nerve fibre layer has already occurred nificant generalized de-
cess. Detection of VFD pro- crease in sensitivity in blue
gression is one of the most
challenging aspects of glau- on yellow perimetry; the
coma management. It may
take years to show a defini- empting the progress of the ing defects detected by stan- degree of change in mean
tive progression on the basis
of WOW perimetric changes. disease. These methods may dard automated perimetry deviation (MD) is also higher
Decision of whether to
change therapy or to oper- especially be helpful in eyes (SAP). The rate of short wave when compared to change in
ate often requires confirma-
tion of the disease progres- with increase IOP and nor- sensitivity loss is also greater MD of white on white perim-

Dr. R.P. Centre for Ophthalmic malVF(ocularhypertension; in patients who demonstrate etry. Thus advancement of
Sciences All India Institute of
Medical Sciences OHT) where these may help progression of visual field cataract may mimic false
New Delhi – 110029
us to identify and treat those defects as compared to those progression if VFD on

patients who are at risk of de- with stable visual fields. SWAP. Though the test can

veloping glaucoma. There Thus SWAP is a sensitive be adjusted for lens changes

are variety of test which has device to monitor the pa- occurring due to age and

been studied for use in diag- tients with early glaucoma- cataract using psychophysi-

nosing and assessing the pro-

gression in a case of glau-

coma but none of them have The upcoming technologies and newer

achieved a global accep- diagnostic modalities may enable us
tance. Major factors prevent- to make a pre-perimetric diagnosis
ing there wide spread use is

the lack of normative data, of glaucoma and pre-empting the

longitudinal data and phe- progress of the disease
nomenal cost of these instru-

ments.

tous damage and to detect cal tests that give an index of

Short wave automated pe- which patients are likely to lens density, it is not a fea-

rimetry (SWAP) have progression of disease. sible option. Use of SWAP in

SWAP is also known as It has also been shown to be clinical practice is generally

blue on yellow perimetry. It effective in managing a case reserved for the confirming

specifically evaluates the of OHT. Patients with OHT or excluding the diagnosis of

blue cones that are lost early have a higher incidence of glaucoma in cases with sig-

in the disease. This technique foveal blue and yellow color nificant signs like elevated

November, 2003 214 DOS Times - Vol.9, No.5

CURRENT PRACTICE

The major drawback with SWAP is images are computed from normal area and a red cross
that it takes about 15% longer time the acquired three-dimen- an abnormal area. It corre-
sional images. A topography lates well with WOW perim-

than SAP and is tiring and difficult for image consists of 256 × 256 etry. HRT has high sensitiv-

the patient individual height measure- ityandspecificitythusallow-
ments which are absolutely ing it to have a very high pre-

scaled for the individual eye cision in early diagnosis and

IOP,suspiciouslookingdiscs require correction, less time examined and have a repro- allowing us to pick up pre-

and normal visual fields in consuming, portable instru- ducibility of the height mea- perimetric glaucoma and

SAP. mentation, good for screen- surements of approximately detect early progression. Its

ing. It has high sensitivity 20 microns at each point. The practical application is in

Frequency doubling perim- and specificity (82% vs 95% topography image is colour cases where disc picture is

etry (FDP) for early glaucoma, 96% and coded, dark colors represent doubtful like with large

This is one of the newest 99%foemoderateglaucoma, elevated structure and light physiological cups, when

perimetric methods. It is be- and 100% for advanced glau- color represents depressed there are no VFDs. Though

lieved that the nonlinear M- coma). The results of FDP areas. After image acquisi- HRThasveryhighreproduc-

cells (a subset of magno- also correlate well with HFA tion the optic nerve head ibility the definition of the

cellular cells) are the cells 30-2 visual fields. The disad- analysis is performed by de- optic disc is conducted

that are damaged at the ear- vantages include lack of any fining the disc margins manually by tracing a line

liest glaucoma insult. These longitudinal data, early pro- manually. Following the along the disc margin and

cells respond to high tempo- thus it any produce substan-

ral and low spatial fre- HRT is a Confocal Laser Scanning tial variability regarding the
quency. This is the basis of ophthalmoscope (CSLO). It helps in final assessment of the optic
FDP. It relies on the principle nerve head.

of frequency doubling. acquisition and quantitative analysis of Optical Coherence tomog-
Frequency doubling illu- raphy (OCT)
three-dimensional images of the
sion: When a sine wave grat-
ing of low spatial frequency posterior segment Optical Coherence To-

is reversed with high tempo- mography (OCT) Scanner is

ral frequency the number of gression and focal defects definitionofthedisccontour, a new diagnostic tool that

bars appears to be doubled. may be missed the software computes and provides structural informa-

FDP uses this illusion to provides a set of stereo met- tion about posterior segment

pick up early loss of the m Heidelberg retinal tomog- ric parameters useful for the with higher resolution than

cells. It is available in both raphy (HRT) description of the shape op- conventional system OCT is

screening and a full thresh- HRT is a Confocal Laser tic nerve head (classify it as analogous to ultrasound B-

old (FT) mode. It is a very Scanning ophthalmoscope being normal or outside nor- scan imaging except that

quick test that takes only 45 (CSLO). It helps in acquisi- mal limits) for contributing light rather than sound

seconds to perform a screen- tion and quantitative analy- to the diagnosis of glaucoma, waves are used in order to

ing test, 3.5 minutes for C- sis of three-dimensional im- and for follow-up of glauco- obtain a much higher longi-

20-1 FT and 6 minutes for C- ages of the posterior seg- matous progression. It gives tudinal resolution (10-

20-5 FT test. The target size ment. It describes the topog- around 23 stereo-metric pa- 15µm). It shows cross-sec-

used in FDP is a square of 100 raphy of retina and optic rameters, like disc area, cup tional living histology of the

in diameter, which is quite nerve head. The HRT uses a area, cup depth, mean RFNL posterior pole with 10 time’s

large when compared to the diode laser with a wave-

largest target sued in length of 670 nm. A three-di- The latest version of GDx-VCC has a
Goldmann. It can detect mensional image is acquired
subtle diffuse changes that as 32 consecutive and equi- variable corneal compensator incorpo-
may not be picked up by distant optical section im- rated into the machine

other perimetric tests but ages, each consisting of

may miss shallow localized 256 × 256 picture elements. thickness etc. It uses Moore- greater resolution and high

defects. Its main advantages The size of the field of view field regression analysis for reproducibility than any

include; ease for the patient, is set to 10° × 10°, 15° × 15°, classifying the different sec- other technique available.

relative resistance to blur or 20° × 20°. Pupil dilation is tors of optic nerve head. OCT is a non-contact, non-

(upto 7D), so patient does not not necessary. Topography Green tick mark denoting a invasive technique.

November, 2003 215 DOS Times - Vol.9, No.5

CURRENT PRACTICE

OCT images are obtained Retinal nerve fibre layer The NFA GDx uses this retardation to
using a trans-pupillary de- analysis measure the RFNL thickness over
livery of low coherence near
infra-red (830nm) from a su- It is believed that almost an150X150 retinal area around the disc
per luminescent diode laser 50% of the RNFL is lost be-
integrated to a standard slit fore the VFD is picked up gives RFNL measurements depth of penetration as com-
lamp biomicroscope using a with reliability on SAP. Reti- in four quadrants of 1200 su- pared to the conventional B-
+78-diopter condensing nal nerve fibre layer analyzer periorly and inferiorly, 500 Scan, making its use limited
lens. Backscatter from the (NFA-GDx) measure the temporally and 700 nasally. for anterior segment assess-
retina is captured using the thickness of peripapillary It instantly compares the val- ment only. The procedure is
same delivery optics and re- RNFL. NFA-GDx works on ues with normative database performed in supine position
solved using a Michaelson the principle of scanning la- provided in the computer after anaesthetizing the eye.
interferometer. Tomo- ser polarimetry. Polarized and shows the level of sig- It uses a small water bath
graphic cross sectional image light is selectively retarded nificance. The parameters filled with a coupling solu-
of retina is constructed by by a polarizing structure outside normal range are tion (1-2% methylcellulose).
performing rapid 100 longi- with alignment perpendicu- flagged in red. It also gives
tudinal A-scans in 2.5 sec- lar to the incident rays of an index number the higher In patients with glau-
onds. The digitalized com- light. When a polarized light the number the higher the coma, it is helpful especially
posite image is produced (near infrared 780nm) is pro- probability that the patient in cases where corneal
onto the computer monitor jected on to the retina, the in- has glaucoma. The cornea edema and corneal opacity
with a false color scale. cident ray and the reflected and lens are also polarizing hinders with gonioscopic
Brighter color representing ray double pass the RFNL be- structures; the latest version assessment. It shows the ex-
highly reflective area and fore emerging. The RFNL of GDx-VCC has a variable act relationship between pe-
darker colors representing has the property of birefrin- corneal compensator incor- ripheral iris and the trabecu-
lower reflectivity. gence thus causes change in porated into the machine. It lar meshwork.
the polarization of the light. compensates for corneal bi-
OCT has been shown to This is called retardation. refringence and gives greater Angle Closure glaucoma:
be clinically useful in evalu- The NFA GDx uses this re- sensitivity to the instrument UBM shows the anterior and
ation of retinal architecture tardation to measure the in discriminating between posterior chamber depth, the
and is useful diagnosis and RFNL thickness over normal and glaucomatous extent of angle closure, iden-
monitoring of various macu- an150X150 retinal area eyes. The machine helps in tify the forward shift of iris
lar pathologies. In glaucoma around the disc. The image diagnosis of pre-perimetric lens diaphragm, helps to dif-
OCT is helpful in providing is color coded from yellow glaucoma and for early de- ferentiate between primary
optic nerve head tomogra- to red to blue representing tection of progression. and secondary angle closure
phy. It can measure the areas from high to low retar- in ACG,
Ultrasound biomicroscopy
OCT can measure the RFNL thickness (UBM) Open angle Glaucoma: it
with a resolution of 10microns when can be used to measure the
UBM uses high resolution angle in degrees, it also
compared to HRT which has a ultrasound (with a high fre- shows the relationship of iris
resolution of 30 microns quency of around 50MHz and posterior bowing of pe-
compared to 10MHz for rou- ripheral iris in pigment dis-
RFNL thickness with a reso- dation. Bright color show tine USG) to evaluate the persion syndrome,
lution of 10microns when thicker RFNL. The images of structural details of the an-
compared to HRT which has blood vessels are excluded terior segment structure at Miscellaneous: It can be
a resolution of 30 microns, by the built in software. It almost microscopic resolu- used to see whether the YAG
thus OCT may identify the does not require pupillary tion. It provides a detailed PI is complete or lamellar, it
focal RNFL defects in early dilatation; the image acqui- two dimensional gray scale can show the patency of scle-
stages of glaucoma. The sition and processing takes images of conjunctiva, cor- rostomy opening in cases of
main drawbacks are again around 30 seconds. For nea, anterior sclera, angle, operated trabeculectomy,
the lack of normative data, analysis a ring is placed anterior chamber, iris, ciliary position of stent tube tip in
expensive instrumentation, along the margins of the op- body, and anterior layers of shunt surgeries, ciliary body
and inability to obtain good tic disc and measurement is lens with zonules. UBM has rotation in cases of malignant
quality images in opaque automatically performed at a resolution of 25-50 microns. glaucoma, and also to detect
media. 1.75 disc diameter away. It The main limitation is the and evaluate the postopera-
tive complications like cilio-
choroidal effusion and cyclo-
dialysis.

November, 2003 216 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

Secondary IOL Implantation of corneal endothelial dec-
ompensation, less angle dis-
Ruchi Goel1 MS, KPS Malik2 MS turbance, less chance of pe-
ripheral anterior synechiae
Secondary intraocular Ø Residual refractive er- terior chamber lens designs and hence less disturbances
lens implantation(IOL) as ror of 6 diopters or were associated with compli- of aqueous outflow.
defined by Azar is insertion more. cations including corneal
of an IOL into an eye which edema, uveitis- glaucoma- Various techniques have
has been rendered aphakic Ø Optical distortion due hyphaema (UGH) syn- evolved over the years to
by prior cataract extraction to IOL decentration. drome, and cystoid macular make scleral fixation of
by any method, or by an ex- edema (CME). Newer ante- PCIOL a simple and safe pro-
change of IOL, which is a Secondary IOL implanta- rior chamber lens designs cedure. Most of the tech-
special case of secondary IOL tion surgery should prefer- with flexible open loops have niques require removal of
implantation. ably be performed 4-6 weeks been associated with fewer vitreous from anterior and
after the initial surgery. In complications. The trend to- posterior chambers. Incom-
The various indications patients with sufficient pos- day is for PCIOL which of- plete vitreous removal can
for secondary IOL implanta- terior capsular support, pos- fers several advantages over cause postoperative compli-
tion are: terior chamber IOL can be AC IOL. It is near to the nodal cations such as tractional
l Monocular aphakia implanted combined with retinal detachment and cys-
cleaning of posterior capsule toid macular edema (CME).
Ø Spectacle or contact Also we observed over the
lens intolerance. Secondary IOL implantation surgery years that mixture of
should preferably be performed 4-6 viscoelastics with vitreous
Ø Old disabled patients weeks after the initial surgery resulted in severe vitritis
with tremor, parkin- postoperatively. The purity
sonism and other with or without capsulo- point of eye and centre of ro- status of different viscoe-
physical disability tomy, synechiotomy, sphinc- tation of eyeball leading to lastics available might be the
which makes handling terotomy and anterior vitre- better optical properties and culprit. Keeping all this
and using of spectacle ctomy. less pseudophakodonesis. mind, we evolved a method
or contact lens difficult. Since it is posterior to the iris, of performing scleral fixation
In patients with insuffi- chances of pupillary block of PC IOL without
Ø Occupational and cir- cient or absent capsular sup- glaucoma are reduced. vitrectomy or viscoelastics.
cumstantial situations port, options available are Endophthalmodonesis de-
where spectacle or anterior chamber IOLs and fined by Binkhorst as the lack We shall now discuss the
contact lens is not suit- scleral fixated posterior of stability in aphakic eye is various techniques of sec-
able, like athletes, chamber IOLs. It is now ac- expected to be decreased due ondary IOL implantation.
dancers, e.t.c. cepted that scleral fixated to support given to the vitre-
posterior chamber lenses are ous by the IOL . Technique for Aphakes
l Contralateral pseudo- better than AC IOLs. With Partial Capsular Sup-
phakia As the lens is away from port
AC IOLs especially the cornea there is much less risk
l Aborted primary IOL im- older close loop or rigid an- Patients, in which IOL im-
plantation plantation had to be aborted
due to posterior capsular tear
l Bilateral aphakia as in
children, patients of
macular diseases like pig-
mentary dystrophy,
coloboma and ARMD.

l IOL exchange may be re-
quired in patients with
Ø Corneal decompensa-
tion/UGH sydrome
due to anterior cham-
ber and iris clip lens.

1. Hindu Rao Hospital, New Delhi Fig.1: Air fluid exchange using 26 G needle. Fig.2: 26 G needle passed 1mm behind the lim-
2. HOD of Ophthalmology, bus through scleral bed into the ciliary sulcus.
Verdhman Eye Hospital,
New Delhi - 110 029

November, 2003 217 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

Fig.3: Docking of straight needle on 10-0 Fig.4: 10-0 prolene suture pulled out of Fig.5: Prolene suture divided into two
prolene into the bevel of 26 G needle.
section using 26 G needle bent in the form halves and tied to the eyelets on IOL

of a hook. haptics.

on the table, the remaining slipped on the superior cap- tated to the surgeon‘s left Ø Check the position of an-
capsule gets fibrosed and sular rim. until the heel can be pivoted terior phase of vitreous
becomes sufficiently into the anterior chamber.
strengthened by about 4-6 Techniqe of Inserting the The implant forceps regrasps Ø Determine the best cor-
weeks. After dilating the pu- AC IOL the superior foot of the im- rected visual acuity
pil completely, slit lamp ex- plant some distance from the (BCVA)
amination should be carried Malpositions in AC IOLs optic. The implant is then
out to outline the capsular are related to errors in lens advanced across the anterior Ø Rule out preoperative
remnants. At times due to size. An undersized lens may chamber until the toe and the glaucoma
formation of posterior syn- cause recurrent uveitis and heel are fixed in the distal Preoperative preparation
echiae, the capsular rim may eventually corneal edema. angle. The superior foot is
not be visible. Severe angle damage may steadied in position with an involves dehydration of vit-
result from an oversized lens instrument held in left hand reous to make the eye
In such a situation, these and may result in uveitis, re- to prevent the distal feet from hypotonous. 200 cc of intra-
synechiae may be broken by current hyphema and even recoiling. The sclera is re- venous mannitol is started 45
sweeping the viscoelastic glaucoma. The correct size of tracted up and out at the in- minutes prior to surgery and
cannula between the poste- the lens is determined by a cision, and the superior root superpinky is tied onto the
rior surface of iris and the horizontal limbal white- to- is tapped into place in the eye ball. 20 minutes before
capsule. A peripheral iridec- white measurement with superior angle. the surgery, peribulbar ana-
tomy can serve as a portal of calipers. To this measure- esthesia is given and
entry to the viscoelastic can- ment is add 1mm to give the The peripheral iridec- superpinky is retied.
nula. If vitreous is present in correct size, regardless of the tomy is made as far away
anterior chamber vitrectomy axis of insertion. from the superior foot as Technique
is performed. After ascer- possible. Eye speculum and supe-
taining the presence of cap- Before inserting the IOL,
sular rim all around, the the pupil is made round by Technique for Aphakes rior rectus are applied. Com-
chamber is filled with air, breaking any synechiae and Without any Capsular Sup- plete aqueous air exchange
posterior chamber IOL is performing vitrectomy if re- port: Scleral Fixation of PC of anterior chamber is per-
held with a lens holding for- quired. Unlike the case in IOL (Author‘S Technique) formed by two 26 G needles
ceps and lower haptic is posterior chamber implants, (figure 1). At this stage the
placed on the anterior sur- pupil is kept constricted. The A thorough preoperative eye is made hypertonous by
face of iris at 6 o‘ clock posi- chamber is formed with air assessment is done to: injecting air. This serves two
tion. The plane between the or viscoelastics. The optic is Ø Detect presence of ante- purposes:
iris and capsule is redefined grasped at its junction with Ø It facilitates the dissection
by injecting viscoelastic. the superior foot, the toe of rior or posterior synechiae
Under direct visualization, the inferior foot is slid Ø Examine anterior cham- of scleral flaps at 2 and 8
the lower haptic is placed on through the incision and ro- o‘clock positions.
the capsular rim present in- ber angle Ø It pushes the vitreous far
feriorly. The trailing haptic Ø Evaluate the fundus behind from the anterior
is then held by the Mc chamber and detaches
Pherson‘s forceps and It is now accepted that scleral fixated any unseen strands of vit-
posterior chamber lenses are better reous from the anterior
than AC IOLs chamber or the incisional
area.
Conjunctival flaps are

November, 2003 218 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

raised at 2 and 8 o‘clock po- Intraoperative Complications of Scleral Fixation
sitions at the limbus. The site

of the exposed sclera should Complication Prevention/Management

be exactly 180 degrees apart Iris and ciliary body trauma Use ab externo approach, Enter 1mm behind the
to prevent IOL decentration. limbus with the 26 G needle/straight needle.
Light cautery is applied on

the scleral beds. Partial thick- 26 G needle emerging in the anterior Insert the 26 g needle first vertically, then hori-

ness scleral flaps are raised chamber instead of posterior chamber zontally keeping the needle close to the iris

at 2 and 8 o‘clock positions Detachment of prolene suture from Avoid undue stress on the prolene suture needle
about 2X2mm in size. A 26 G its needle junction
straight needle is passed
from the temporal scleral bed Decentring of IOL on the table Exit of suture from the sclera should be exactly
1mm from the limbus at right 180 degrees apart A loose suture may get en-
angle to the sclera and then tangled on the haptic or optic. Therefore IOL
tilted to pass its tip and shaft should be pulled out of the section, entanglement
horizontally, hugging the if any is removed and IOL is redialed

posterior surface of iris, to One of the suture breaks from the If one of the haptics is still in place, then pass the

pass through the ciliary sul- haptic during IOL placement straight needle on 10-0 nylon from the scleral bed

cus into the posterior cham- to exit at the corneoscleral section. Manipulate

ber. This needle is kept the detached haptic to the section, tie the prolene

steady by holding it in left suture to it without disturbing the other haptic
hand (figure 2). Straight and gently place the IOL in the sulcus

needle on 10-0 prolene(W-

1713 Ethicon) is similarly The straight needle with 26 G needle (figure 3). 26 G rying the 10-0 prolene suture

passed from nasal scleral bed prolene suture following it, needle is then pulled out of with it. Suture will be seen

into the posterior chamber. is docked into the lumen of the temporal scleral bed car- stretchedacrosstheposterior

chamber in the air. In case the

air leaks from the AC it

should be promptly re-

placed. 6-6.5mm corneosc-

leral section is then made.

Straight 26 G needle, its bevel

bent in the form of hook is

used to engage the prolene

suture in the posterior cham-

ber and pulled out of the

section(figure 4).

The prolene suture is cut

Fig.6: Prolene suture made taut by pulling at Fig.7: Anchoring suture: Bite taken with 10,0 into two and tied to the IOL
both the ends to bring the IOL in place. nylon on scleral bed just a little away from exit of haptics(figure 5). The final
10,0 prolene. position is such that if the IOL
is placed with the superior

haptic facing the right, then

the left side suture is tied to

the superior haptic and the

right side suture to the infe-

rior haptic. The IOL chosen

is the one with eyelets on the

haptics.

After making sure that the

AC is deep with air, the IOL

is held firmly with straight

Fig.8: Anchoring suture: Knot made between Fig.9: Anchoring suture: A bite is taken from lens holding forceps and the

10,0 prolene and 10,0 nylon suture. undersurface of scleral flap. Continued on page 222

November, 2003 219 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

Continued from page 219 balanced tension pulls the on 10-0 nylon is passed be- Ø Endophthalmitis
scleral flap back covering the hind the iris near its root, The technique followed
The trend today is mesh of suture knots. Same taken out and passed
for PCIOL which procedure is repeated on the through the inner lip of the by us in the last few years,
other side. Conjunctival flap sclera and the knot is secured has given acceptable results
offers several is sealed with bipolar cau- in the section itself. without a major complica-
tery. tion. We have come across an
advantages over Post Operative Regimen occasional case of decentring
One Haptic Fixation of the Oral ciprofloxacillin and suture erosion.
AC IOL IOL
500mg BD for five days, in- To conclude, transscleral
lower haptic is placed at 6 If there is some support travenous dexamethasone fixation of posterior chamber
o‘clock position behind the present inferiorly, the supe- 4mg daily for three days fol- IOL is now almost univer-
iris. The optic is released in rior haptic can be fixed by an lowed by tapering dose of sally preferred over anterior
the pupillary area and the ab interno approach to the oral steroids and topical an- chamber IOLs. The tech-
trailing haptic is grasped inner lip of the scleral tibiotics, steroids as well as nique of scleral fixation with
with a Mc Pherson‘s forceps. wound. The AC is cleared of mydriatics were prescribed preoperative hypotony,
The Mc Pherson‘s forceps is any vitreous and chamber is for four weeks. without viscoelastics and
held with the hand in the su- formed with an air bubble. without vitrectomy gives a
pinated postion, IOL is ro- good BCVA with minimal
tated clockwise and hand is Transscleral fixation of posterior cham- complications.
pronated releasing the trail- ber IOL is now almost
ing haptic when it reaches Suggested Readings
the 3 o‘clock position. The ro- universally preferred over anterior
tation of hand will place the chamber IOLs 1. Malik KPS, Goel R. Secondary
superior haptic behind the
iris. The prolene suture ends implantation of IOL. In
are then made taut (figure6).
The section is closed using Manual of small incision cata-
10-0 nylon suture and AC is
filled with air. ract surgery. CBS publishers.

Anchoring sutures with IOL is placed in front of the Postoperative Complica- 2003; 113-120.
10-0 nylon on curved needle iris vertically, the lower hap- tions of Scleral Fixation
are applied on the scleral bed tic lying in front of the iris at 3. Solomon K, Gussler J.R,
near the exit of the prolene 6 o‘clock position. Viscoelas- Following complications
suture holding the IOL (fig- tic is injected between iris have been reported by vari- Gussler C, Van Meter WS. In-
ure 7). One arm of the an- and remaining capsule to ous surgeons.
choring suture is firmly tied create a plane for placement Ø Suture related cidence and management of
to the IOL holding suture by of lower haptic and optic on
2-3 knots (figure8). The same the capsule. After placing the a. Erosion through the complications of
needle is then passed from lower haptic, trailing haptic sclera
the undersurface of the is secured with a 10-0 nylon transsclerally sutured poste-
raised scleral flaps and tied suture to the inner lip of b. Erosion through con-
to the IOL holding suture sclera.For this the end of the junctiva rior chamber lenses. J Cataract
(figure9), a controlled and haptic is cauterized and
made bulbous to prevent c. Loosened suture Refract Surg 1993;19:488-492.
slippage of knot. The knot is d. Broken suture
tied to the most convex por- Ø Decentration of IOL 9. Uthoff D, Teichman K D. Sec-
tion of the haptic. The needle Ø Glaucoma
Ø Cystoid macular edema ondary implantation of scleral
Ø Severe vitritis
Ø Choroidal haemorrhage fixated intraocular lenses. J
Ø Retinal detachment
Cataract Refract Surg 1998;

24:945-950.

13. Maggi R, Maggi C. Sutureless

scleral fixation of intraocular

lenses. J Cataract Refract Surg

1997;23:1289-1294.

30. Mc Cluskey P, Hamsberg B.

Long term results using scleral

fixated posterior chamber in-

traocular lenses. J Cataract

Refract Surg 1994;20:34-39.

Keep April 3-4, 2004 Free for

ANNUAL CONFERENCE

of Delhi Ophthalmological Society

November, 2003 222 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

Management of Hypotony after For an intrableb ap-
Glaucoma Surgery proach, the tip of the needle
is advanced into bleb and
R.N. Bhatnagar MS, DOMS, Sachin Walia MS, Deepak Sharma MS blood is injected slowly. For
a peribleb approach, the
When the term hypotony require intervention. The in- overfiltering blebs. Applica- blood is injected adjacent to
is used in ophthalmology, a dications for intervening in tion to conjunctiva using the bleb. The most common
low intraocular pressure an eye with prolonged hy- microdrops produces blan- complication of this proce-
(IOP) is generally implied. potony must be individual- ching and shrinkage of the dure is hyphema formation,
The statistical definition of ized. The following indica- tissue and a subsequent in- more common with the
hypotony refer to an IOP of tions should be considered: flammatory response is pro- intrableb approach.
less than 9mm Hg, represent- duced.
ing 6mm Hg two standard a. low-pressure syn- Laser Grid Technique
deviations below the mean drome; Cryotherapy of Bleb The laser grid technique
IOP of the general popula- Like that with trichoroa-
tion. We refer to hypotony in b. a persistent bleb leak; has been described for treat-
the statistical sense as IOP c. imminent risk of bleb cetic acid, bleb cryotherapy ment of blebs that are
lower than 9 mm Hg and to failure in the early postop- is best for shrinking large overfiltering, leaking or
the structural and functional erative period; blebs and is not as effective painful. The YAG laser in the
changes associated with low d. persistent ocular pain for ischemic blebs. thermal mode with laser set-
IOP as the low-pressure syn- from hypotony. ting at a power of 3 to 4 joules
drome. Noninvasive Techniques Autologous Blood Injection and an offset of 3 to 4 (0.9-1.2
Observation The autologous blood in- mm), approximately 30 to 40
Causes of Postoperative Spontaneous resolution spots are delivered in a grid
Hypotony of hypotony is more likely to jection technique can be used pattern with the aiming
occur in the early postopera- for management of both thin beam focused on the bleb
Postoperative hypotony tive period than in the late overfiltering blebs and bleb surface.
develops most commonly in
association with trabecule- Spontaneous resolution of hypotony Compression Sutures
ctomy especially when such is more likely to occur in the early Compression sutures can
adjunctive antimetabolites postoperative period than in the
as 5-flourouracil or mitomy- be used for treatment of blebs
cin C are used, but may de- late postoperative period that are leaking or painful. A
velop also after glaucoma trapezoid pattern with 9-0
seton surgery, cataract ex- postoperative period. Spon- leaks. Topical anesthesia and nylon suture is formed over
traction, cyclodestruction, taneous resolution may be antibiotic or half-strength the bleb and is tied tightly.
goniotomy, trabeculotomy hastened with use of aque- betadine solution are admin-
and cyolodialysis. ous suppressants, by mini- istered prior to the proce- Cataract Extraction
mizing use of steroids, and dure. The patient can be su- As hypotonous eyes often
Following are the causes by patching. Additional pine or seated at the slit lamp.
of postoperative hypotony: noninvasive measures can be Viscoelastic can be injected have accelerated cataract de-
1. Overfiltering Bleb considered which include intracamerally, if desired. velopment and because 25 to
2. Choroidal Effusion use of Blood (approximately 1 ml) 50% blebs may demonstrate
3. Retinal Detachment is withdrawn from an an- partial or total decrease in
4. Cyclodialysis Cleft 1. Cyanoacrylate Glue tecubital vein using a tuber- function after cataract sur-
5. Aqueous Suppression 2. Simmons Shell Tam- culin syringe and a 25 gauge gery, cataract surgery may
ponade needle. The needle is improve hypotony in some
Intervention to Reverse changed to a sterile 30 gauge eyes with a visually signifi-
Hypotony Invasive Techniques needle. The needle should cant cataract.
Trichloroacetic Acid Appli- puncture the conjunctiva at
Not all hypotonous eyes cation least 5 mm away from the Closure of Bleb Leak
bleb to lessen the chance of In the early postoperative
Deptt. of Ophthalmology Trichloroacetic acid has an iatrogenic leak.
GMC & Rajindra Hospital,Patiala been advocated as a method period, direct suturing of
to restrict the area of bleb leaks may be necessary
and successful. A 10-0 or 11-
0 nylon suture is preferable.

November, 2003 223 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

Surgical Revision of Bleb tion, in turn aggravating hy- Prevention of Postopera- 3. Placement of Extra
and Scleral Flap potony and the tendency to Scleral Flap Sutures
more choroidal effusion. tive Hypotony
Peripheral conjunctiva Thus, any surgical procedure 4. Avoidance of Early
can be mobilized to cover an aimed at reversing hypotony As managing postopera- Suture Release
excised bleb by creating a re- should give consideration to tive hypotony often is diffi-
laxing incision through pos- drainage, of choroidal fluid. cult, its avoidance is desir- 5. Special attentiveness
terior conjunctiva. Indications for drainage in- able. Strategies to prevent to patients with high risk for
clude kissing choroidals, flat postoperative hypotony in- hypotony which include
Drainage of Choroidal Fluid anterior chamber or immi- clude: young patients or high
The presence of supracho- nent bleb failure resulting myopes.
from hypofilteration. 1. Restricted use of An-
roidal fluid contributes to timetabolites
reduced aqueous produc-
2. Meticulous Closure of
Scleral Flap

Dr. R.B. Jain a senior member and past president of our society is contesting the forthcoming
AIOS election for the post of Vice President at Varanasi in January, 2004. All members are
requested to join and give him wholehearted support.

Brief Resume:
Dr. R.B. Jain, M.S. (Ophthal.); D.O. (London), D.O. (Dublin); M R C Ophth. (U.K.)
Director, RBM EYE INSTITUTE, C-2/1, Prashant Vihar, Delhi – 110085, Tel.:011-27563939,
27561166
Dr. Jain did M.B.B.S. and later M.S. from Maulana Azad Medical College, New Delhi. After
working as registrar spent 5 years in UK. He became a Consultant there but returned to serve
mother India. Joined the faculty of MAMC, but had been in practice since 1980. Visits United
Kingdom regularly to keep in touch with the newer development in Ophthalmology and get
first experience.

Positions held:
¨ President, Delhi Ophthalmological Society - 1997-98
¨ Joint Secretary, All India Ophthalmological Society 1996-99
¨ Chairman Registration Committee Xth Asia-Pacific Congress, New Delhi 1985
¨ Organising Secretary, Golden Jubilee Conference of AIOS, New Delhi 1992. He was instrumental in raising the standards of

AIOS conferences to international levels and this proved to be a trendsetter for subsequent conference.
¨ Chairman Reception Committee of 55th and 61st AIOS Conference, New Delhi 1997 & 2003.
¨ Ophthalmic adviser to Dr. A.V. Baliga foundation for prevention of blindness in children
¨ Ophthalmic advisor to projects of CSIR (Govt. of India)
¨ Organised numerous Workshops / Courses conducted by international experts
¨ Senior Retinal Surgeon at Mohan Eye Institute, New Delhi since 1980

Scientific Highlights:
¨ He is one of the pioneers in the field of Fundus Fluorescein Angiography and Laser Photocoagulation and Retinal Surgery

in India for the past 30 years.
¨ His thesis work on fluorescein angiography in diabetic retinopathy in 1971 is probably the first thesis published on FFA

from India.
¨ He has published original case reports in international journals and for one of these Thomas D. Duane quotes his name in

the Textbook “Clinical Ophthalmology”.
¨ He has the honour of being invited as Guest speaker in large number of state ophthalmic societies
¨ He has attended a very large number of national and international conferences and have presented papers and chaired/

moderated a number of sessions.
¨ He was awarded Honorary Membership of the Royal College of Ophthalmologists, U K
¨ He was appointed Examiner for FRCS (Ophthalmology) by the Royal College of Surgeons, Glasgow.
¨ Dr. R. B. Jain is a Life member of the following societies:

w Delhi Ophthalmological Society w All India Ophthalmological Society w National Society for Prevention of Blindness,
India w Vitreo-Retinal Society, India w Delhi Medical Association w Indian Medical Association w Royal College of Ophthal-
mologists, U.K

November, 2003 224 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

Retained Intraocular Foreign Body: when undertaking the study
Investigations of the CT.

Lt. Col. V.S. Gurunadh, Col. D.P. Vats, Lt. Col. A Banarji, The disadvantage of the
Lt. Col. M. Bhadauria. CT scan is that foreign bod-
ies smaller than 2mm may
The most important man- surgical techniques, this sce- Detection & Location not be picked up. It is also
agement problem in a case nario is now not existent. First and foremost is a difficult to differentiate an
of an open globe injury and intra-scleral foreign body
much more so in a case of a It would have been a boon thorough indirect ophthal- from an extra-scleral by a CT
suspected globe penetration if equipment could be in- moscopy for if the media is scan. The other problem is
is the issue of a retained in- vented which could detect clear, as it can luckily be at the shattering effect caused
tra-ocular foreign body the presence, location, type times, the entire examination by metallic RIOFB. The most
(RIOFB) in the posterior seg- and teactivity of an RIOFB. is over and nothing more is important draw-back how-
ment. This is particularly so But alas! Such equipment is required. The present day ever is the inability to study
in cases of media opacity like still a utopian dream. But workup would consist of the the vitreo-retinal interface.
cataract and or vitreous when it comes to deal with a following.
haemorrhage which is the suspected case of a RIOFB, The ease of interpretation
rule rather than an exception these are precisely the an- a) Conventional X-Rays is the major advantage of this
in these cases. The oph- swers required. In this con- This must always be or- modality. The cost of the in-
thalmic literature is replete text it would be worthwhile vestigation may inhibit one
with the anecdotal instances to note that the previously dered in every case as it of to order the same but in these
of the detection of these as useful but time consuming medico-legal importance. days of COPRA it is a neces-
well as their removal. It is and less accurate localization Apart from that, it is of im- sity. In fact, one can go to an
worthwhile here to quote portance in delineating a ra- extent of mandating this in-
from the chapter on RIOFB vestigation as an essential
in Albert & Jackobiecs’ text The most important management one.
book of ‘Principle and prac- problem in a case of an open globe
tice of Ophthalmology’. injury and much more so in a case of a c) Ophthalmic ultra-sound
suspected globe penetration is the issue This is the back one of in-
“……Gone are the days of of a retained intra-ocular foreign body
the giant magnet, when the vestigations for a RIOFB. A
dramatic command of ‘Turn (RIOFB) combined A/B scan is a
it on,’ would allow the pre- must. Imaging should be
viously unseen foreign body methods such as soft tissue dio-opaque foreign body done an maximum as well as
to suddenly appear at the films to detect foreign bod- and nothing else. at low gain. The echo of a
magnet’s tip, often with frag- ies in the anterior segment; RIOFB would be percent at
ments of lens, uvea, vitreous the Sweet localization tech- b) Computerized Tomogra- all gains and could throw a
and retina, not to mention the nique, which involved no phy (CT) shadow. The location of the
instruments and the tug on contact with the globe but RIOFB and its size can be
the operating room person- considerable inaccuracy; the In recent years this is determined so as to plan the
nel’s watches and other me- Comberg technique, which emerging as the modality of surgery and in experienced
tallic belongings in the vicin- was dangerous because of choice in the delineation of a hands it is 100% accurate.
ity…” the need to place a contact RIOFB. The radiologist must
lens with a metal market on be asked to take either 1-mm The advantage of this mo-
With advances in the field the eye as also the limbal ring contiguous sections of the dality is that it is the only
of radio-diagnosis and imag- method; and the various globe or 1.5mm sections modality to study the vitreo-
ing and the development of metal locators of Berman, taken at 1-mm intervals re- retinal interface particularly
vitreo-retinal diagnostic and Roper-Hall and Bronson sulting in a 0.5 mm overlap. in the face of vitreous
Turner have all been rel- It is necessary that the patient haemorrhage which is of
Army Hospital egated to historical interest does not move his head dur- paramount importance be-
(Research & Referral) only. ing the procedure and the fore contemplating surgery.
Delhi Cantt-110 010 same should be ascertained In this situation it is neces-
sary to find out the presence
of associated retinal detach-
ment and the occurrence of
posterior vitreous detach-
ment. Ultasound is not lim-

November, 2003 225 DOS Times - Vol.9, No.5

MANAGEMENT PEARLS

ited by the nature of the bubbles are –1000 HU. In recent years CT Scan is emerging
RIOFB and hence can be used However the argument as the modality of choice in the
in any situation. delineation of a RIOFB
against the necessity to de-
d) MRI scan termine the nature of the for- mendation for the day. In & SF Byme. Modern diagnos-
Movement of metallic for- eign body is that in majority majority of cases a RIOFB is tic techniques in the evalua-
of the circumstances the usually removed because of tion of ocular trauma. Oph-
eign body is the biggest con- RIOFB should be removed ir- the efficacy of modern thalmology Clinics of North
cern with a MRI scan and respective of the type. This vitreo-retinal surgical tech- America Vol.8 No. 4, Dec.
therefore conventional wis- think is perhaps the result niques. Thus the need to find 1995, 589-608.
dom is against the use of this that sunflower cataract and out the nature of the RIOFB 2. Alexander. R Gaudio. Intra-
modality in the investigation the Fleischer’s ring that de- does not arise. ocular foreign bodies. In Prin-
of a RIOFB. veloped over the course of ciples and practice of Ophthal-
Suggested reads mology II Ed. Vol. III, WB
The disadvantage of the CT scan is Saunders, Philadelphia, 2000,
that foreign bodies smaller than 1. Deborah G. Keenum, C Bold 2514-2524.
2mm may not be picked up
Monthly Meetings Calendar
Nature of RIOFB observation of a copper in- For The Year 2003-2004
traocular foreign body that
There is no foolproof was left in the eye undis- 27th July, 2003 (Sunday)
method by which the nature turbed for prolonged peri- Army Hospital
of a RIOFB can be detected ods because of the greater
so that inert foreign bodies damage caused by attempt- 30th August, 2003 (Saturday)
can be left without removal. ing to remove it. Sir Ganga Ram Hospital
Relevant history might help.
By CT scan the absorption ERG 27th September, 2003 (Saturday)
characteristics of RIOFBs However there might be Hindu Rao Hospital
have been quantitated in
Hounsfield units (HU) and circumstances which might 19 October, 2003 (Sunday)
have been compared with prevent one from attempting DOS Midterm Conference
the absorption of various a removal of a RIOFB like a
materials already deter- one-eyed individual with a 1st November, 2003 (Saturday)
mined experimentally. visual acuity of 6/9 or so. In R.P. Centre for Ophthalmic Sciences
Wood is the least dense of all such situations ERG can be
non-metallic foreign bodies, good tool to keep the patient 29th November, 2003 (Saturday)
followed by plastic and then under follow up. Dr. Shroff’s Charity Eye Hospital
glass. All metallic foreign
bodies have the same ab- Conclusion 27th December, 2003 (Saturday)
sorption of +3071 HU and are Every case of open globe Venu Eye Hospital & Research Centre
impossible to detect on CT.
Glass has an attenuation co- injury should be investigated 31st January, 2004 (Saturday)
efficient that ranges between for a RIOFB. Ideally two mo- Safdarjung Hospital
+300 to +600 HU, plastic dalities should be used, one
from +20 to 0 HU, wood from being USG. CT scan coupled 28th February, 2004 (Saturday)
–50 to –199 HU, and air with an ophthalmic USG A/ M.A.M.C. (GNEC)
B scan should be the recom-
28th March, 2004 (Saturday)
OBITUARY Mohan Eye Institute

w Dr. Lt. Col. H.K. Chawla, who left for heavenly abode 3-4th April, 2004 (Saturday & Sunday)
at New Delhi. We pray for the peace of the departed Annual DOS Conference
soul.
w Dr. J.K. Pasricha, who left for heavenly abode at
New Delhi. We pray for the peace of the departed
soul.

November, 2003 226 DOS Times - Vol.9, No.5

APPLIANCES

Multifocal Electroretinogram (M-ERG)
– Practical Applications

Raj Vardhan Azad MD, FRCS Ed, Nikhil Pal MD, YR Sharma MD, Atul Kumar MD

Introduction the technique is too time con- Fig.1: a, Schematic representation of one cycle of the MF0F0 paradigm.
The Multifocal electrore- suming to allow testing of M, m-sequence; F, global flash; 0, dark frame, each separated by 13.33
more than only a few retinal milliseconds. b, Waveform response of the MF0F0 stimulation mode.
tinogram (M-ERG) intro- areas during any one session. The first shaded area (A) demonstrates the N1 and P1 peaks of the first-
duced by Sutter and Tran in In contrast, M-ERG enables order component. The second shaded area (B) contains the first induced
1992 allows recordings of assessment of up to hun- component (the effect of each focal flash on the first global flash).The
multiple spatially resolved dreds of distinct retinal ar- third shaded area (C) contains the second induced component (the ef-
ERG responses from the eas within approximately 8 fect of each focal flash on the second global flash).
retina over a central area of minutes per eye. A record-
about 25 degrees. Using the ing in a light adapted state Fig. 2: Multifocal ERG recorded using the RETISCAN (Roland Consult,
Multifocal electroretino- offers local information com- Germany) system
gram (M-ERG) not only the parable to cone responses in
answer to a certain stimulus the full field ERG. Retinal using focal ERG or pattern Vascular disorders, dia-
of the retina on the whole but function suffering from re- ERG, the M-ERG indicates betic retinopathy and retinal
also the reactions of several gional disorders in outer reti- not only a central loss of func- inflammations-These disor-
areas of the retina are mea- nal layers can be described tion in maculopathies but ders may preferentially af-
sured in a single recording. in detail with this technique. also a detailed description of fect inner and midretinal lay-
To do so, the retina is divided the extent of the lesion. ers and are frequently asso-
into several areas, each of Applications
which are stimulated with This technique has been
special design series(m-se-
quence) of bright and dark applied to the study of retini-
stimulus frames. As each of tis pigmentosa, macular de-
the stimulus areas produces generation, glaucoma, and
a reaction according to the diabetes.
stimulus used, a summed
signal is generated at the Maculopathies- The cen-
cornea which consists of the tral responses are lost or
reaction of all single areas. markedly diminished sur-
This summed signal contains rounded by normal or at least
the reaction of all stimulated clearly recordable response.
areas of the retina, and with This leads to a crater or vol-
the help of special evaluation cano like appearance in the
method (cross-correlation- three-dimensional plot of re-
function) it is possible to ex- sponse density. The loss of
tract each single answer of central activity can be found
every corresponding area in all kind of maculopathies
from this summed signal. as in ARMD, vitteliform
maculopathies, Stargardt
Focal electroretinography disease, macular holes, juve-
has been used to evaluate nile retinoschisis, central se-
retinal function within the rous retinopathy and others.
macula (central 3-10°) but, It is especially valuable in
diseases of the macula with
Dr. R.P. Centre for Ophthalmic small or no morphological
Sciences All India Institute of changes in the fundus. In
Medical Sciences contrast to a single response
New Delhi – 110029

November, 2003 227 DOS Times - Vol.9, No.5

APPLIANCES

Fig.3: d. Trace arrays of 61 first order kernel ERG minance of 185 to 200 cd/m2,
waves in normal eye and dark frames 1 to 2 cd/
m2, resulting in local con-
Fig.3: a. Schematic representation of the ar- trasts of 98% to 99%. Each
rangement of the six concentric rings hexagon is temporally
modulated between light
Fig.3: b. Topographic pattern of response den- Fig.3: e. Averaged ERGs of the concentric ring and dark according to a bi-
sity calculated as scalar product in a normal groups in normal eye nary m-sequence with a base
eye. The central peak corresponds to the interval of approximately
macular area and the minimum on the left to 13.3 msec. Observers fixate
the area of the optic nerve head (blind spot). a small gray spot in the cen-
ter of the stimulus during 8-
and visual path- proparacaine), a Burian minute recording sessions.
Allen bipolar contact lens To improve fixation stability,
way-Glaucomas electrode is placed on the test the sessions are broken into
eye and a ground electrode 30-second segments with
are a group of clipped to the left earlobe. brief rest periods between
Patients are positioned 33cm each segment. Signals are
complex disor- from the stimulus monitor. amplified (gain, 106), band-
Stimulus clarity is optimized pass filtered(10-100 Hz), and
ders which affect by over-refraction, and then recorded with a sampling in-
a final adjustment of test dis- terval of 0.83 msec (163 per
preferentially tance is made to maintain video frame). The amplitude
constant stimulus magnifica- and implicit time of all local
but not exclu- tion (test distance, 33 cm for (first-order) ERG responses
plano over-refraction). The are analyzed using a com-
sively ganglion stimulus is presented on a 17- puter program (Matlab;
inch monitor (Dotronix, Inc., Mathworks, Natick, MA).By
cells. In Glau- New Brighton, MN), driven cross-correlation of the
at a 75-Hz frame rate and summed raw data signal and
coma, diffuse consist of an array of 61/ the stimulus sequence used,
103/241 hexagonal elements an array of 61 or 103 first or-
changes in cone of black or white color across der kernel focal ERG traces
a field subtending 44° hori- can be calculated.
Fig.3: c. Schematic representation of esti- responses occur. zontally and 40° vertically.
White hexagons have a lu- Conclusion
mated scalar product values (as SDs from the Based on the first order

mean of the control group) in hexagonal areas Method kernel of the M-ERG , func-
in normal eye tional topographies of pa-
Multifocal tients with outer or mid-reti-
nal diseases can be derived
ciated with a break-down of ERGs can be re- in a considerable short time.
the blood retinal barrier and corded using the VERIS sys- In addition to the power of
consecutive retinal edema, tem (EDI,San Mateo, USA) full-field ERG, Pattern -ERG
leading to an overall de- or RETISCAN(Roland Con- and VEP in the layer-by-
crease of MFERG amplitude sult, Germany). Pupils are layer topographic descrip-
in entire test field and also fully dilated (7 mm) using tion of function of the visual
delay in implicit time. 1.0% tropicamide and 2.5% system, the multifocal tech-
phenylephrine. After topical nique adds the possibility of
Disorders of ganglion cell corneal anesthesia (0.5% objective fields testing.

Suggested Reading

1. Mohidin N, Yap MK, Jacobs
RJ. The repeatability and variabil-

November, 2003 228 DOS Times - Vol.9, No.5

APPLIANCES

Fig.4: a. Trace arrays of 61 first order Fig.4: b. Topographic pattern of response Ophthalmol 2002; 105(2):151-78
kernel ERG waves in Stargardt's disease density calculated as scalar product in 5. Greenstein, VC, Chen, H,
Stargardt disease depicting the central Hood, DC, Holopigian, K, Seiple,
trough. W, Carr, RE. Retinal function in
diabetic macular edema after fo-
cal laser photocoagulation Invest
Ophthalmol Vis Sci 2000; 41,3655-
3664
6. Hood DC, Wladis EJ, Shady S,
Holopigian K, Li J, Seiple W. Mul-
tifocal rod electroretinograms. In-
vest Ophthalmol Vis Sci 1998;
39(7):1152-62

ity of the multifocal electroretino- Horiguchi M, Suzuki S, Tanikawa Where is my copy of DOS Times?
gram for four different electrodes. A. Clinical evaluation of multifo-
Ophthalmic Physiol Opt 1997; cal electroretinogram. Invest Dear DOS members, anyone who could not receive DOS
17(6):530-5 Ophthalmol Vis Sci 1995; 36(10): Times from the month of November, 2003 onwards.
2. Kretschmann U, Seeliger MW, 2146-50
Ruether K, Usui T, Apfelstedt- 4. Fortune B, Cull G, Wang L, Please Contact: MR. SUPROTIK BANERJI
Sylla E, Zrenner E. Multifocal elec- Van Buskirk EM, Cioffi
troretinography in patients with GA.Factors affecting the use of M/s. Syntho Pharmaceuticals Pvt. Ltd.
Stargardt's macular dystrophy. Br multifocal electroretinography to 31/16, 2nd Floor, Old Rajinder Nagar, New Delhi-60
J Ophthalmol 1998; 82(3):267-75 monitor function in a primate
3. Kondo M, Miyake Y, model of glaucoma. Doc E-mail: [email protected]

November, 2003 229 DOS Times - Vol.9, No.5

ART OF REFRACTION

Types of Frames and Spectacle Lenses

Monica Choudhry B.Sc. (Hons.), Priyanka Dhingra B.Sc. (Hons.), Jeewan S. Titiyal MD

The market has a plethora weight of the lens. A high Flint is lead oxide. Barium These lenses came to us in
of lens materials continu- index lens will be heavier and flint are used in fused 1970 and are chemically
ously adding more and due to higher specific grav- bifocals because of their known as CR-39 or Allyl di
more new types. The key is ity. The reduced thickness of higher refractive index. The glycol carbonate. The newer
to select the right lens mate- the lens may compensate for comparison figures are plastic used these days is
rial based on the patient pre- the weight to some extent. shown in a tab[ -1 to -5 D ]le polycarbonate. It has higher
scription. The suitability of below. refractive index and better
the lens depends on the oc- Abbe value: It is the mea- impact resistance.
cupational demands and life sure of the dispersion of the Due to high specific grav-
style of the patient and chromatic aberration. The ity and low abbe, flint has Glass Vs Plastic
above all the budget of the values range from 30 - 60 of the disadvantage of being The refractive index of
patient. current materials. Lower the heavier with higher chro-
abbe value higher is the matic aberration. plastic is 1.498 which is
We all know the basic chromatic aberration. Abbe lesser than glass. This adds
lens material is glass and value of 30 signifies higher Other high index glasses thickness to plastic lenses.
plastic. The current trends chromatic aberration and The market has available Abbe value is as good as
have added higher index the value of 50 is less aber- glass i.e. 57.8 compared to
glass or plastic; new designs ration. 1.6, 1.7, 1.8, 1.9 high index that of crown being 58.5.
like aspheric; various tints The comparisons are as fol- lenses useful for higher Specific gravity is 1.32
and coats and improved im- lows powers as this makes the against 2.54 of glass i.e. al-
pact resistance. All these lens thinner. The ingredient most half. So plastic is the
new additions are to im- Lens Material of high index glass is tita- choice if weight is the crite-
prove a) visual comfort, b) Glass nium oxide. The higher in- ria. Thus the advantages of
visual performance, c) ap- dex glass has higher specific CR-39 over glass are:
pearance of lens and eye and It is the most common gravity and lower abbe so
d) add protection to eye and single vision lens. The ingre- the selection for the patient 1. Lightness 2. Impact re-
lens. To understand the dients are silica, sodium ox- should be according to the sistance 3. tint ability and 4.
lenses let us discuss their ide and calcium oxide. Glass requirement of the patient. Versatility in design. Plas-
basic characters: REFRAC- is also available as Barium or tics also have some disad-
TIVE INDEX, SPECIFIC Flint glass. The material in Plastic Lens or Hard Resin vantages like 1. Increased
GRAVITY, ABBE VALUE, surface absorption 2.
UV ABSORPTION. Warpage 3. a glazing in-
creased thickness and 4.
Refractive index: Chang- unstability at higher tem-
ing or increasing the index peratures.
reduces the edge thickness
of minus and reduces the The ophthalmic glass in-
centre thickness of plus dustry in India is rapidly
lenses. The volume of the showing a decline due to the
material is reduced and we advent of plastics. Now we
get flatter surfaces.

Specific gravity: It is den-
sity or weight of the lens per
cubic cm. It specifies the

Dr. R.P. Centre for Ophthalmic
Sciences All India Institute of
Medical Sciences
New Delhi – 110029

November, 2003 230 DOS Times - Vol.9, No.5

ART OF REFRACTION

Crown glass Ref. index Abbe Specific Crown Ref. Index Abbe S. Gravity
CR - 39 value gravity Barium 1.523 58.5 2.54
Polycarbonate 1.523 Flint 1.610 55.9 3.36
1.6 Index plastic 1.498 58.5 2.54 1.690 30.9 4.23
1.7 Index Glass 1.586 57.8 1.32
1.8 Index Glass 1.596 30.0 1.20 43% and polycarbonate al- This coating is though ideal
Spectralite 1.34 lows only 1%. So plastics are for all, yet more suitable for
(Aspheric ultra) 1.70 36 2.99 definitely better than glass. stage performers, high pow-
1.80 30.8 3.39 ered glasses, VDU users and
1.537 25.4 1.21 Tints and Coats drivers.
47.0 Scratch resistance coating
Polarised lenses
Cellulose Acetate is the most commonly SRC is done for plastics to They polarize the light in
used material because of its lightweight prevent easy scratching of
plastic. There are two kinds one direction. The layer of
and unlimited coloring options of coatings. Quartz is an in- the polarsing material is en-
organic coating: This coat- closed in the glass or plas-
have optically perfect plas- for the patient is also re- ing cracks with heat like in tic.
tics that are as scratch resis- duced. Such lenses are best cars’ hot air or while warm-
tant as glass. In the last two for powers above 4 D. The ing frame. The other coating Photochromatic lenses
years our outlet glass: plas- lenses are mostly plastic and is Siloxane Polymer coat. Photochromatic glass has
tic ratio has changed from also available in high index. This is an organic coating
95:5 to 20:80. preferred over quartz coat- silver halide added to it and
Lenticular design ing. The coating can be iden- in case of plastic a surface
Polycarbonate We all may be aware of tified by noticing water treatment is done. The
It is the higher index plas- beeds on the surface of the photochromatic lenses be-
lenticular lenses i.e. central lens. side, being alternative to
tic which has superior im- optic bowl with carrier of sunglasses, are good UV
pact resistance. It has low lens power. They allow a Anti reflection Coating protection glasses.
abbe value and such lenses high power portion to be This coating reduces re-
may need Anti Refractive made in smaller diameter Tints
Coating (ARC). The surface (40 mm) thus reducing cen- flections from the surface Several tints are given to
also scratches easily. It is the tral thickness, weight, and and increase transmittance
lens of choice in active chil- peripheral prism effects. of light. To the viewer the glass or plastic for patients
dren, athletes, and industrial These lenses are getting less distractions are avoided benefit such as pink for com-
workers. popular due to poor specially in prismatic glasses fort and cosmoses, gray–for
cosmesis, small field of view and to the observer there are uniform absorption in vis-
Design based Choices and ring scotoma closer to no reflections on the glass. ible spectrum, green for IR
Aspheric field of view. absorption, brown looks

Aspheric lenses are lenses UV Protection
in which the radius of cur- This is a property of the
vature changes gradually
from centre to periphery. lens material. With the in-
The asphericity is denoted creasing awareness of UV
by the drop - eg. a 4 drop protection among customers
will mean 4D less at the pe- and also the need of it in
riphery. The aspheric lens many occupations we need
adds advantages of decreas- to understand which lens is
ing central thickness reduc- best protective. Plastics are
ing weight and aberrations. not inherently effective in
The cosmetic appearance absorbing UV but the addi-
and the field is improved. tives in them increase UV
The spectacle magnification absorption. CR-39 allows

November, 2003 231 DOS Times - Vol.9, No.5

ART OF REFRACTION

psychologically warmer Progressives – they are strong, resistant to corrosion Frame styling
than grey. Alpha pale blue multifocal lenses which and economical. Other com- Your eye wear dispenser
tint, B1 B2 a green blue tint mimic natural vision and mon metals used are Nickel,
etc. are other tints available consist of distance, near and stainless Steel and titanium. ids expert to help you select
in the market. intermediate zones. These frame. Face shape, face fea-
lenses are getting popular The plastic frame materi- tures and overall skin colour
The cost is a great factor rapidly. They have the ad- als used are Cellulose ac- should be considered while
for the patients, thus we can vantage of correcting near etate, cellulose propionate, selecting the frame. Frame
suggest the best, leaving the and intermediate vision es- carbon fiber, polycarbonate, selection according to frame
decision on the patient. We pecially for computer users. Polymide , Optyl or nylon. is to select a frame that is op-
should never estimate for They are also cosmetically Cellulose Acetate is the most posite to the patient’s facial
the patient. In our country better and the most suitable commonly used material be- shape. Like an aviator or
the high index lens may for all presbyopes cause of its lightweight and square shape will suit a tri-
range from Rs.450-900. A unlimited coloring options. angular face and a round
high index plastic costs any- After knowing the vari- Polycarbonate frames are face will suit a rectangular
thing between 1000 - 2000. ous lens materials it is our very strong and used more or round face.
An ARC coating is for responsibility to suggest to as safety frames in industry.
around Rs.400 and SRC the patient the best lens suit- Carbon Frames are light- Not every prescription
coating for Rs.100. A photo- able for him. Selection de- weight with good tensile can fit into all frames. Plas-
chromatic glass is for Rs.200 pends on the patients pre- strength but limited dark tic lens material can only be
to 900 and a good scription, occupation, bud- colours only are available. fitted in rimless frames. A
photochromatic plastic is for get and the life style. high minus prescription
Rs.2500. Frame Styles should select a small frame
Frame Types Whether plastic or metal, to avoid ugly thick periph-
Single vision, Bifocal and Along with the lens ma- ery. High prescriptions are
Multifocal lenses ophthalmic frames are avail- not cosmetically good for
terial which is suitable to the able in many different styles. high powers. A progressive
Single vision lenses – they patient, it becomes neces- Types or frames available lens also has typical frame
correct vision for one focal sary to decide about the include size selections.
length, either near or dis- frame which gives ultimate
tance. satisfaction to the patient. Full Frame, Semi rimless, Some patients with con-
full rimless or drill mount, tact dermatitis and allergies
Bifocals – They correct vi- There are various materi- and half eyes. should be advised to change
sion at two distances, usu- als available in frames. The the material of the frame or
ally distance and other near two main types are the metal A full frame has plastic or nose bridges.
at 16 inches from the eye. and the plastic frames. The metal material which sur-
Different types of bifocals metal frames are of Monel, rounds the lens completely. The goal is to meet the pa-
available are Kryptok, D Nickel, Nickel silver, stain- A combination of metal and tients’ visual expectations
type or executive. less steel, Titanium, Alumi- plastic is also available. and enhance the overall ap-
num etc. Monel is the most Rimless or semi rimless are pearance of patient and
Trifocals – they have 3 common material used to very popular these days. lenses.
viewing distances .One dis- produce metal designs. It is
tance, second near and the a combination of nickel and Half eye frames are used Summary:
third intermediate usually copper. It is stable and for patients with near vision Advanced technology
30 inches away. correction only.
has made possible the devel-
opment of new designs that
meet the patients vision
needs better than ever.
Today’s consumers are an
ideal market for these lenses.
Sales of progressives, as-
pheric, high index and poly-
carbonate materials, plastic
photochromatics and Anti-
reflection treatments are ris-
ing dramatically as the
population grows in India.

November, 2003 232 DOS Times - Vol.9, No.5

DOS QUIZ NO. 5

DOS QUIZ NO. 5

1. Osler’s sign is seen in ........................................................................................................................................
2. Site of lesions in one and half syndrome ....................................................................................................
3. “Double floor” sign in x-ray skull is found in .................................................................................................
4. “Salmon Patch Haemorrhage” is seen in .......................................................................................................
5. Vogts triad is commonly seen in .................................................................................................................
6. Most common type of paranasal mucocele ....................................................................................................
7. pH of Tear film is .............................................................................................................................................
8. Visual field is largest for which colour .......................................................................................................
9. Best Diagnostic test for “Best Disease” is .....................................................................................................
10. Corneal ulcer with “cracked wind shield” appearance is caused by .......................................................

Rules:
l Please send your entries to the DOS office latest by 25th November, 2003.
l Prize Rs. 500/- Courtesy: Syntho Pharmaceuticals
l Quiz Trophy will be given to the member who answers maximum number of quizes in a

year during the Annual GBM of DOS.

Answers for the DOS Quiz No. 3

1. Which condition doestnot obeys the Herings law DVD
2. IOL master is based on which principal? INTERFEROMETRY
3. Most common cause of perinaud syndrome in children PINEALOMA
4. Most common site of block in acquired NLD block AT THE JUNCTION OF SAC & NLD
5. "Dawson Finger" in MRI of brain is seen in MULTIPLE SCILEROSIS
6. Memantine is being tried in which ocular disorder NEUROPROTECTIVE AGENT IN GLAUCOMA
7. Dose of TPA in subretinal hemorrhage is 6-10qmg (3000-5000 I.U)
8. Most common aganism for graft infection in India is STAPHYLOCOCCUS EPIDERMIDIS
9. All extra ocular muscle can be resected except SUPERIOR OBLIQUE
10. Gene for hereditary retinoblastoma is situated in CHROMOSOME 13

November, 2003 233 DOS Times - Vol.9, No.5

JOURNAL ABSTRACTS

Laser in-situ keratomileusis (LASIK) Epi-LASIK: Transmission electron mi-

after penetrating keratoplasty croscopy of the specimens proved the

Vajpayee RB, Sharma N, Sinha R, Bhartiya P, Titiyal JS, manual technique is less invasive to epi-
Tandon R.
Rajendra Prasad Centre for Ophthalmic Sciences, All India thelial integrity than LASEK using either
Institute of Medical Sciences, New Delhi, India. alcohol concentration.
Surv Ophthalmol. 2003 Sep-Oct;48(5):503-14.
Pallikaris IG, Naoumidi II, Kalyvianaki MI, Katsanevaki VJ.
Laser in situ keratomileusis (LASIK) after penetrating J Cataract Refract Surg. 2003 Aug;29(8):1496-501.
keratoplasty has been used more commonly for the correction Vardinoyiannion Eye Institute of Crete, Crete, Greece.
of myopia or myopic astigmatism and less so for hypermetro-
pia or hyperopic astigmatism. The primary goal after LASIK Authors compared the effect of mechanical and alcohol-as-
in such cases is resolution of sufficient myopia and astigma- sisted excision on the histological ultrastructure of epithelial
tism to allow spectacle correction of the residual refractive er- disks from human corneas. Ten eyes of 10 patients were
ror and decrease anisometropia. All sutures should be removed deepithelialized by 1 of 2 two techniques. In 6 eyes, a custom-
prior to LASIK and the interval between penetrating kerato- ized instrument was used to mechanically separate the epi-
plasty and LASIK should be a minimum of 1 year. Preopera- thelial layer. In 4 eyes, the epithelial disks were obtained us-
tive evaluation includes refraction, slit-lamp biomicroscopy, ing the conventional laser-assisted subepithelial keratectomy
corneal topography, and specular microscopy. The technique (LASEK) technique; that is, with alcohol concentrations of 15%
of LASIK surgery after penetrating keratoplasty is similar to and 20%. All specimens were assessed by light and electron
the standard procedure. However, many variations have been microscopy, and the histological findings of the 2 methods were
described. These include maneuvers during surgery such as compared. Transmission electron microscopy showed that
augmentation with arcuate cuts on the stromal bed and topo- when the epithelial disks were excised by mechanical separa-
graphically guided LASIK. Other variations are relaxing inci- tion, the lamina densa and lamina lucida were preserved and
sions followed by LASIK surgery and sequential treatment by the hemidesmosomes had normal morphology along almost
LASIK, that is, raising of the flap as a first stage procedure the entire length of the basement membrane. The basal epi-
followed by ablation if required, 4 to 6 weeks later after relifting thelial cells of the separated epithelial disks showed minimal
the flap in the second stage. Improvement in both uncorrected trauma and edema. Specimens obtained using 15% and 20%
visual acuity and spectacle-corrected visual acuity, as well as alcohol concentrations showed formation of cytoplasmic frag-
a decrease in spherical equivalent, cylinder, and anisometro- ments of the basal epithelial cells, enlargement of the intercel-
pia, has been reported in various studies. All grafts were clear lular spaces, and extensive discontinuities in the basement
and no occurrence of wound dehiscence has been reported. membrane, which was excised at the level of the lamina Lu-
Intraoperative complications include hemorrhage, micro- cida. Mechanical separation did not affect the normal cell mor-
keratome failure, flap buttonhole, dislocation, and perforation. phology of the excised epithelial disks. Transmission electron
Postoperative complications include undercorrection, microscopy of the specimens proved the manual technique is
decentered ablation, and regression. Re-enhancements after less invasive to epithelial integrity than LASEK using either
LASIK following keratoplasty are possib le with acceptable alcohol concentration.
visual outcome.taract surgery.

NATIONAL OPHTHALMOLOGY Update-2003

Venue: Army Hospital (Research & Referral)

Keep December 6th & 7th, 2003 free for

National Ophthalmology Update-2003

Organised by:
Department of Ophthalmology
Army Hospital (Research & Referral), Delhi Cantt-110 010
Ph.: 25668181, 25668183, (M): 9810447698,
E-mail: [email protected]

November, 2003 234 DOS Times - Vol.9, No.5

DELHI OPHTHALMOLOGICAL SOCIETY Stamp Size
2 Colour
(LIFE MEMBERSHIP FORM)
Photograph

Name (In Block Letters) _________________________________________________________________________
S/D/W/o _____________________________________________________________ Date of Birth _____________
Qualifications _________________________________________________________ Registration No. __________
Sub Speciality (if any) ___________________________________________________________________________
ADDRESS

Clinic/Hospital/Practice ______________________________________________________________________
_______________________________________________________________ Phone _________________
Residence ________________________________________________________________________________
_______________________________________________________________ Phone _________________
Correspondence ___________________________________________________________________________
_______________________________________________________________ Phone _________________
Email ___________________________________________________________ Fax No. ________________
Proposed by
Dr. _______________________________ Member Ship No. ______________ Signature _________________
Seconded by
Dr. ________________________________ Membership No. ______________ Signature _________________

[Must submit a photocopy of the MBBS/MD/DO Certificate for our records.]

I agree to become a life member of the Delhi Ophthalmological Society and shall abide by the Rules and Regula-
tions of the Society.
(Please Note : Life membership fee Rs. 3100/- payable by DD for outstation members. Local Cheques acceptable,
payable to Delhi Ophthalmological Society)
Please find enclosed Rs.____________in words ______________________________________________________ by
Cheque/DD No.______________________ Dated____________ Drawn on_____________________________________

Three specimen signatures for I.D. Card. Signature of Applicant
with Date

FOR OFFICIAL USE ONLY

Dr._______________________________________________________________has been admitted as Life Member of
the Delhi Ophthalmological Society by the General Body in their meeting held on________________________________
His/her membership No. is _______________. Fee received by Cheque/DD No._______________ dated__________
drawn on __________________________________________________________________.

(Secretary DOS)

INSTRUCTIONS

1. The Society reserves all rights to accepts or reject the application.
2. No reasons shall be given for any application rejected by the Society.
3. No application for membership will be accepted unless it is complete in all respects and accompanied by a Demand Draft of Rs. 3100/- in

favour of “Delhi Ophthalmological Society” payable at New Delhi.
4. Every new member is entitled to received Society’s Bulletin (DOS Times) and Annual proceedings of the Society free.
5. Every new member will initially be admitted provisionally and shall be deemed to have become a full member only after formal ratification

by the General Body and issue of Ratification order by the Society. Only then he or she will be eligible to vote, or apply for any Fellowship
propose or contest for any election of the Society.
6. Application for the membership along with the Bank Draft for the membership fee should be addressed to Dr. Jeewan S. Titiyal, Secretary,
Delhi Ophthalmological Society, R.No. 476, 4th Floor, Dr. R.P. Centre for Ophthalmic Sciences, AIIMS, Ansari Nagar, New Delhi – 110029.
7. Licence Size Coloured Photograph is to be pasted on the form in the space provided and two Stamp/ Licences Size Coloured photographs
are required to be sent along with this form for issue of Laminated Photo Identity Card (to be issued only after the Membership ratification).

DOS Credit Rating System Report Card

DCRS July 2003 – Army Hospital (R&R)

Total No. of Delegates ....................................................................................................................................................................... 121
Delegates from Out side (N) ............................................................................................................................................................. 114
Delegates from Army Hospital (n) ........................................................................................................................................................7
Overall assessment by outside delegates (M) ............................................................................................................................ 888.5
Assessment of case presentation-I (Dr. Lt. Col.A. Banarji) by outside delegates .................................................................... 803.5
Assessment of case presentation-II (Dr. Lt. Col. (Mrs.) Madhu Bhaduria) by outside delegates ............................................ 814.5
Assessment of clinical talk (Dr. D.P. Vats) by outside delegates ................................................................................................ 862.5

DCRS 30th August, 2003 – Sir Ganga Ram Hospital

Total No. of Delegates ................................................................................................................................................................. 82
Delegates from Out side (N) ....................................................................................................................................................... 66
Delegates from Sir Ganga Ram Hospital (n) ............................................................................................................................... 16
Overall assessment by outside delegates (M) ...................................................................................................................... 468.5
Assessment of case presentation-I (Dr. Jasmita Popli) by outside delegates ..................................................................... 440.5
Assessment of case presentation-II (Dr. Anita Sethi) by outside delegates ........................................................................ 476.5
Assessment of Clinical Talk (Dr. S.N. Jha) by outside delegates .................................................................................... …..450.0

DCRS 27th September, 2003 – Hindu Rao Hospital

Total No. of Delegates ................................................................................................................................................................. 70
Delegates from Out side (N) ....................................................................................................................................................... 59
Delegates from Hindu Rao Hospital (n) ...................................................................................................................................... 11
Overall assessment by outside delegates (M) ......................................................................................................................... 432
Assessment of Case Presentation-I (Dr. Ruchi Goel) by outside delegates ............................................................................ 414
Assessment of Case Presentation-II (Dr. A.K. Nagpaul) by outside delegates ................................................................... 401.5
Assessment of Clinical Talk (Dr. Ruchi Goel) by outside delegates .................................................................................... ..433.5

DCRS 1st November, 2003 – Dr. R.P. Centre for Ophthalmic Sciences

Total No. of Delegates ................................................................................................................................................................. 86
Delegates from Out side (N) ....................................................................................................................................................... 62
Delegates from Dr. R.P. Centre for Ophthalmic Sciences (n) ..................................................................................................... 24
Overall assessment by outside delegates (M) ......................................................................................................................... 473
Assessment of Case Presentation-I (Dr. Sachin Kedar) by outside delegates ....................................................................... 447
Assessment of Case Presentation-II (Dr. Murlidhar R.) by outside delegates ..................................................................... 455.5
Assessment of Clinical Talk (Prof. S. Ghose) by outside delegates .................................................................................... ..460.5

November, 2003 236 DOS Times - Vol.9, No.5

DCRS

DOS Credit Rating System (DCRS)

The rate of technological and academic obsolescence stitution was the cultivation and promotion of the Sci-
in Ophthalmology has reached astronomical levels in ence of Ophthalmology in Delhi.
recent times. What was advanced yesterday may already
be obsolete today. The rapid strides in skills and knowl- In a bid to strengthen our efforts in this direction and
edge have created a need for an extremely intensive fulfil the vision of our society’s founders, DOS announces
Continuing Medical Education programme. the DOS Credit Rating System (DCRS), the details of
which are given below. Our Primary objective is to pro-
DOS has always been in the forefront of efforts to mote value-based knowledge and skills in Ophthalmol-
ensure that its members remain abreast with the latest ogy for our members and give recognition and credit
developments in Ophthalmology. Among the impor- for efforts made by individual members to achieve stand-
tant objectives formulated by the founders of our con- ards of academic excellence in Ophthalmic Practice.

DOS announces a new era in Continuing Medical Education

DOS CREDIT RATING SYSTEM (DCRS)

(A new chapter in CME)

Credits

1) Attending Monthly Clinical Meeting* † (For full attendence) 10

2) Making Case Presentation at Monthly Meeting** 15

3) Delivering a Clinical Talk at Monthly Meeting** 15

4) Free Paper Presentation at Annual Conference (To Presenter)** 15

5) Speaker/Instructor** in : Monthly Symposium 15

: Mid Term Symposium 15

: Annual Conference 15

6) Registered Delegate at Mid Term DOS Conference 20

7) Registered Delegate at Annual DOS Conference 30

8) Full Article publication in Delhi Journal of Ophthalmology/DOS Times 15

9) Letter to Editor/Correspondence in DOS Times 10

——————————————————————————————————————————————

If any of the presentations is given an Award – be based on the total score of members who attend

Additional 20 bonus Credits. divided by number of members who attended. In-

Member who have earned 100 Credits, are enti- stitutional assessment regarding decision to retain
tled to: the institute for the next year will be based on total
score by all delegates who attend the meeting di-
a) Certificate of Academic Excellence in Ophthal- vided by average attendence of all 8 meetings.
mic Practice.
Please note that the Institutions’ grading in-
b) 50% exemption of Registration fee at next An- creases if the attendance at its meeting is higher (i.e.
nual DOS Conference. more than the average attendence of the eight
monthly meetings).
c) DOS Travel fellowship for attending confer- ——————————————————————
ence. A member to be eligible for the fellowship * Based on Signature in DCAC
needs to score 100 DCRS points. ** Subject to Submission of Full Text to Secretary, DOS
† Credits will be reduced in case attendence is only for
If any member earns 200 Credits, he/she shall, in part of the meeting.
addition to above, be awarded Certificate of Distin-
guished Resource-Teacher of the Society.

Institutional assessment for best performance will

November, 2003 237 DOS Times - Vol.9, No.5

EVENTS

Forthcoming Events – NATIONAL

———————————————————————————————————————————————————

Event Conference Date Venue Contact Person and Address

———————————————————————————————————————————————————

National Ophthalmology 6th-7th Ayurvigyan Auditorium Contact Person: Lt. Col. A Banarji
Update Dec. 2003 Army Hospital Army Hospital (Research & Referral)
Delhi Cantt, Near Dhuala Kuan, Delhi - 110010
Phone: 25668185/8184/8187/8183

7th Annual Conference of 13th-14th Akal Eye Hospital & Contact Person: Dr. Balbir Singh Bhaura (M.S.)
Punjab Opthalmological Society Dec. 2003 Laser Centre Akal Eye Hospital & Lasik Laser Centre,
Model Town, Jalandhar - 144 003
Telefax: 0181-2273606, 2271606, 2461606, 5073604
E-mail: [email protected]
Conference E-mail: [email protected]

62nd All India 8-11 Banaras Hindu Conference Secretariat: Prof. V. Thakur
Ophthalmological Conference Jan. 2004 University, Varanasi Nataraj Eye & Laser Centre, 156B, Ravindrapuri,
Varanasi - 221 005, India
XI International Congress of 23-27th L.V. Prasad Eye Phone: 0542-2276505, 09415201167
Ocular Oncology Jan. 2004 Institute, Hyderabad Fax: 0542-2276707
Email: [email protected]
Contact Person: Dr. Santosh G. Honavar,
ICOO Secretariat, LV Prasad Eye Institute,
LV Prasad Marg, Banjara Hills, Hyderabad
Tel.:+91-40-23548267, e-mail: [email protected]

Annual DOS 3rd-4th India Habitate Centre Contact Person: Dr. Jeewan S. Titiyal,
Conference Secretart (DOS) R.No. 476, 4th Floor,
April 2004 Lodhi Road, New Delhi Dr. R.P. Centre for Opthalmic Sciences,
New Delhi - 110 029 Ph.: 26589549,
Fax : 26588919, E-mail: [email protected]
Website: http://www.dosonline.org

INTERNATIONAL

Event Conference Date Venue Contact Person and Address

———————————————————————————————————————————————————

Euro Asian Opthalmology Congress 11-15 Shanghai, China Contact: Euro Asian Congress Secretariat
Dec. 2003 Tel.: 86-2163-031-757, Fax: 86-2163-029-643
E-mail: [email protected]

8th ESCRS Winter Refractive 23-25 Barcelona Contact: ESCRS Temple House, Temple Road,
Surgery Meeting Jan. 2004 Blackrock, Co Dublin, Ireland.
Tel.: 3531-209-1100 Fax: 3531-209-1112
E-mail: [email protected]

International Symposium on 11-14 MONTE CARLO Contact: Iliana Eliar, Assistant Project Manager,
Ocular Pharmacology and Mar. 2004 Kenes International Global Congress Organizers
& Association Management Services
E-mail: <[email protected]>

ASCRS Annual Symposium 1-5 SAN DIEGO, CA USA Contact: ASCRS Tel.: 1703-591-2220
May 2004 Fax: 1703 591 0614, Web: www.ascrs.org

XXII Congress of the ESCRS 18-22 PARIS, FRANCE Temple House, Temple Road, Blackrock,
Co Dublin, Ireland
Sept. 2004 Tel.: 3531-209-1100 Fax: 3531-209-1112
E-mail: [email protected]

November, 2003 238 DOS Times - Vol.9, No.5

TEAR SHEET NO. 5

Surgical Management of Refractive Errors

I. LOW TO MODERATE MYOPIA iii. Phakic lens (Artisan) : + 4 to + 10 D,

i. RK (Radial Keratotomy) : [-1 to -3 D] iv. ICL: +3 to +6 D
Abandoned v. Laser thermokeratoplasty : + 1 to +2 D,

*Mini RK – incisions 4/ 6/ 8, length 2 or 3 mm vi. ICSR : +1 to + 2 D
vii. Lensectomy + IOL ± piggy bag IOL: > 10 D
ii. PRK (Photorefractive Keratectomy) : [ -1 to -5
D] IV. ASTIGMATISM
other indications are after RK, LASIK button
hole, incomplete LASIK flap,unable to user (i) Astigmatic Keratotomy:
microkeratome due to high brow, tight lids, nar- a. Arcuate and Transverse incisions
row palpebral aperture. b. 5- 8 mm optic zone diameter
Disadv: Delayed visual recovery, corneal haze

iii. LASIK (Laser Assisted in Situ Keratomileusi): c. 2/3 effect with 1st incision,
[Upto-10D] most commonly used technique. d. Less effect in young patients,
e. Effect: Arcuate > Transverse > Radial
iv. ICSR (INTRA CORNEAL STROMAL RINGS): f. Coupling effect ( Absent with Excimer)
[-1 to -3 D] PMMA rings in mid peripheral
stroma Safe, low cost, rapid visual recovery, re- (ii) Excimer (PRK & LASIK) : up to 6D
versible a. Myopia- Elliptical/cylindrical ablation for
myopic astigmatism,
v. GIAK (Gel injectable adjustable keratoplasty): Ablation by flying spot laser
[-1 to -4D] Inject semi solid gel in Para central b. Hyperopia- Ablation by scanning spot laser
stroma, Adv. Adjustable
V. PRESBYOPIA
vi. LASEK (Laser Assisted Sub Epithelial Keratom-
ileusis) : new evolving safer procedure

II. HIGH MYOPIA- [> -10 D] i. Monovision
i. Anterior chamber Phakic lens : Artisan lens a) Myopic: LASIK, LASEK
(Verisyse), Nu-Vita lens (PMMA angle fixated b) Hyperopic: LASIK, LASEK
lens)
Adv – Reversible, Disadv- Safety & perfect IOL ii. Myopic & Hyperopic: Phakic IOL, Clear lens
formula not known, more surgical skill extraction with IOL

ii. Precrystalline phakic IOL : Barraquers PMMA, iii. Experimental procedures:
Implantable foldable contact lens (ICL) a) Laser Thermoscleroplasty
b) INTACS
III. HYPEROPIA c) Scleral expansion with scleral implant over
cilliary body
i. LASIK: +1 to + 5 D,

ii. PRK: +1 to +4 D

November, 2003 Harish Pathak, Vijay B Wagh, Harminder K Rai
Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS

239 DOS Times - Vol.9, No.5