September-October, 2022 Vol, 28 No. 5

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 51 Microbiological Profile When scrapings are taken under anesthesia, culture positivity rates are 34-88%. These rates decrease when the child has been started on empirical therapy or based on superficial scrapings obtained without anaesthesia.[11,16,17] A geographic variation has been reported in the microbiological spectrum, with the most common organisms in pediatric keratitis being bacteria in North Indian studies and fungus in South Indian studies; staphylococcus being the commonest of the bacteria and Fusarium, the most typical fungus. Staphylococcus epidermidis has been reported to be the commonest etiological agent in various studies abroad. There has been an association between Pseudomonas infection and contact lens wearers.[4-6,10,12-15,17] Viral keratitis in children leads to a higher rate of morbidity because of a higher rate of recurrence than adults. The late onset of appropriated therapy further complicates this due to late presentation and misdiagnosis.[18] Treatment The four commandments for treating a case of pediatric keratitis are: 1. Empirical/cocktail therapy should be avoided 2. The use of multiple topical agents to be avoided to increase compliance 3. Monotherapy is preferred in non-serious cases 4. Amblyopia management The initiation of antimicrobials before microbiological evaluation decreases the culture positivity rates, further delaying the diagnosis of the etiological agent and complicating the course of the disease. Monotherapy for a bacterial infection includes a fourth-generation fluoroquinolone. The antimicrobial sensitivity of these agents is shown to be 80-95% in studies, making them the firstline agent.[19] Studies show resolution in up to 75% of cases using an antimicrobial monotherapy alone.[20] On comparison with combination therapy with fortified antibiotics with fluoroquinolone monotherapy, the treatment outcome of the two groups showed no significant difference. The group with the combination therapy had a decreased frequency of drug instillation.[21] The preferred agent for monotherapy in fungal keratitis is 5% natamycin, which has a broad spectrum of action against yeasts and filamentous fungi. In very uncooperative children, where topical administration of antimicrobials is not feasible, repeated subconjunctival injection of antimicrobials under sedation has also been advocated.[1,22] In non-healing ulcers, surgical interventions may be necessary similar to that in adults, including cyanoacrylate glue with bandage contact lenses, tectonic grafts, etc. The need for surgical interventions is seen in less than 20% of cases of pediatric keratitis. Most of these are cases of protein energy malnutrition or bilateral keratitis. These are usually the patients associated with poor outcomes. Poor outcome is also seen in patients with fungal keratitis.[23-26] Rehabilitation The outcome of pediatric keratitis is denoted by the successful resolution of infection and the appropriate rehabilitative measures. These measures include measures to prevent amblyopia, including managing irregular astigmatism by contact lenses, lamellar keratoplasties, or penetrating keratoplasties for visual rehabilitation. Additional surgeries may also be needed to manage a complicated cataract or restore the globe’s anatomy. Visual rehabilitation by keratoplasties in children has its own set of challenges, including faster wound healing causing repeated loosening of sutures, increased propensity to develop inflammation, vascularisation, post PK glaucoma and graft rejection. Post-keratoplasty patching or other measures are needed to prevent amblyopia. Summary Late presentation, inadequate and unreliable history, and difficult evaluation make diagnosing a pediatric keratitis difficult. This makes examination under anaesthesia at the primary presentation a necessity, and the role of microbiological diagnosis in such cases is indispensable before initiating the antimicrobial therapy. The outcome of these cases depends on long-term skilled care with a multipronged approach addressing the active infection and inflammation, restoration of the anatomy of the ocular structures if disturbed, and successful visual rehabilitation of the patient to decrease the risk of permanent visual disability in the form of amblyopia. Conflict of Interest none Keywords Pediatric cornea, corneal diseases, keratitis in children Disclosure of Funding none Corneal Infections

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 52 Figure 1: Serial photographs of a six-year-old with corneal infiltrates, depicting the approach in such a case. (a) Detailed slit lamp evaluation based on age and cooperation. (b) Slit lamp photograph showing central corneal infiltrates with hypopyon (c) The OR setting showing examination under anaesthesia. (d) The microbiological kit with slides and culture media (e) shows the procedure of corneal scarping performed under anaesthesia (f) & (g) Shows Fusarium on KOH and cultures (Credits: SCEH Lab Services). Corneal Infections

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 53 Figure 2: Rehabilitation of a patient in a healed keratitis (a) Corneal scar post-healed viral keratitis (b) Clear graft post penetrating keratoplasty for visual rehabilitation. References 1. Ormerod L.D., Murphree A.L., Gomez D.S., Schanzlin D.J., Smith R.E. Microbial Keratitis in children. Ophthalmology. 1986; 93:449– 455. [PubMed] [Google Scholar] [Ref list] 2. Hsiao CH, Yeung L, Ma DH et al. (2007) Pediatric microbial keratitis in Taiwanese children: a review of hospital cases. Arch Ophthalmol 125:603–609. 3. Maurin J.F., Renard J.P., Ahmedou O. Corneal blindness in tropical areas. Med Trop (Mars) 1995; 55: 445–449. [PubMed] [Google Scholar] [Ref list] 4. Cruz O.A., Sabir S.M., Capo H., Alfonso E.C. Microbial keratitis in childhood. Ophthalmology. 1993; 100:192–196. [PubMed] [Google Scholar] 5. Song X, Xu L, Sun S, Zhao J, Xie L. Pediatric microbial keratitis: a tertiary hospital study. Eur J Ophthalmol 2011; PII: 5F077621-4EB2- 45C9-8D08-0EF9C819AEBB. doi: 10.5301/EJO.2011.8338. 6. Al-Otaibi AG. Non-viral microbial keratitis in children. Saudi J Ophthalmol. 2012 Apr;26(2):191-7. doi: 10.1016/j.sjopt.2011.10.002. Epub 2011 Oct 13. PMID: 23960991; PMCID: PMC3729792. 7. Whitcher J.P., Srinivasan M. Cornel ulceration in the developing world- a silent epidemic. Br J Ophthalmol. 1997;8:622–631. [PMC free article] [PubMed] [Google Scholar] 8. Srinivasan M., Gonzales C.A., George C. Epidemiology and etiological diagnosis of corneal ulceration in Madurai, South India. Br J Ophthalmol. 1997;81:965–971. [PMC free article] [PubMed] [Google Scholar] 9. Resnikoff S., Pascolini D., Elya Ale D. Global data on visual impairment in the year 2002. Bull World Health Organization. 2004;82:844– 855. [Google Scholar] 10. Soleimani, M., Tabatabaei, S.A., Mohammadi, S.S. et al. A ten-year report of microbial keratitis in pediatric population under five years in a tertiary eye center. J Ophthal Inflamm Infect 10, 35 (2020). https://doi.org/10.1186/s12348-020-00227-x. 11. Kaur, Manpreet; Titiyal, Jeewan S. Commentary: Pediatric infectious keratitis. Indian Journal of Ophthalmology: March 2020 - Volume 68 - Issue 3 - p 440-441 doi: 10.4103/ijo.IJO_47_20. 12. Clinch T.E., Plamon F.E., Robinson M.J., Cohen E.J., Barron B.A., Laibson P.R. Microbial keratitis in children. Am J Ophthalmol. 1994;117:65–71. [PubMed] [Google Scholar] 13. Kunimoto D.Y., Sharma S., Reddy MK; Mirobial keratitis in children. Ophthalmology. 1998;105:252–257. [PubMed] [Google Scholar] 14. Vajpayee R.B., Ray M., Panda A. Risk factors for pediatric presumed microbial keratitis: a case control study. Cornea. 1999;18:565–569. [PubMed] [Google Scholar] 15. Singh G., Palanisamy M., Madhavan B. Multivariate analysis of childhood microbial keratitis in South India. Ann Acad Med. 2006;35:186–189. [PubMed] [Google Scholar] 16. Young AL, Leung KS, Tsim N, Hui M, Jhanji V. Risk factors, microbiological profile, and treatment outcomes of pediatric microbial keratitis in a tertiary care hospital in Hong Kong Am J Ophthalmol. 2013;156:1040–4e2 Cited Here |PubMed 17. Chirinos-Saldaña P, Bautista de Lucio VM, Hernandez-Camarena JC, Navas A, Ramirez-Miranda A, Vizuet-Garcia L, et al Clinical and microbiological profile of infectious keratitis in children BMC Ophthalmol. 2013;13:54 Cited Here | PubMed. 18. Revere K, Davidson SL. Update on management of herpes keratitis in children. Curr Opin Ophthalmol. 2013 Jul;24(4):343-7. doi: 10.1097/ ICU.0b013e32836227d8. PMID: 23665524. 19. Rossetto JD, Cavuoto KM, Osigian CJ, Chang TC, Miller D, Capo H, et al Paediatric infectious keratitis: A case series of 107 children presenting to a tertiary referral centre Br J Ophthalmol. 2017;101:1488– 92 Cited Here |View Full Text | PubMed. 20. Jeng B.H., McLeod S.D. Microbial keratitis. Br J Ophthalmol. 2003;87:805–806. [PMC free article] [PubMed] [Google Scholar] 21. Shah V.M., Tandon R., Dip N.B., Satapathy G. Randomized clinical study for comparative evaluation of fourth-generation fluoroquinoCorneal Infections

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 54 lones with the combination of fortified antibiotics in the treatment of bacterial corneal ulcers. Cornea. 2010;29:751–757. [PubMed] [Google Scholar] [Ref list] 22. Parks D.J., Abrams D.A., Sarfarazi F.A. Comparison of topical ciprofloxacin to conventional antibiotic therapy in treatment of ulcerative keratitis. Am J Ophthalmol. 1993;115:471–477. [PubMed] [Google Scholar] 23. Jhanji V., Naithani P., Lamoureux E., Agrawal T. Immunization and nutritional profile of cases with atraumatic microbial keratitis in preschool age group. American J Ophthalmol. 2011;151:1035–1040. [PubMed] [Google Scholar] 24. O’ Brien T.P., Maguire M.G., Fink N.E. Efficacy of ofloxacin vs cefazolin and tobramycin in the therapy for bacterial keratitis. Report from the Bacterial Keratitis Study Research Group. Arch Ophthalmol. 1995;113:1257–1265. [PubMed] [Google Scholar] 25. Wong T.Y., Fong K.S., Tan D.T. Clinical and microbial spectrum of fungal keratitis in Singapore: a 5-year retrospective study. Int Ophthalmol. 1997;21:127–130. [PubMed] [Google Scholar] 26. Baum J., Barza M. Topical versus subconjctival treatment of corneal ulcers. Ophthalmology. 1983;90:162. [PubMed] [Google Scholar] Dr. Manisha Acharya, MS Head-Cornea Services, Medical Director-Eye Bank Dr Shroff’s Charity Eye Hospital, 5107, Kedarnath Road, Daryaganj, New Delhi. Corresponding Author: Corneal Infections

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 55 Non-Commercial Drug Formulations for Corneal Infections Gajashree S, MS, Shweta Verma, MS, Ram Kishan Duvesh, MS, Harinder Singh Sethi, MD, DNB, FRCS, Anuj Mehta, MS Department of Ophthalmology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. The delivery of antimicrobials in the form of fortified, intravitreal, subconjunctival allows better minimal inhibitory concentration of medications at the site of infection. That is possible when concentration of drug used, and their formulation is known. Hence this article describes about drug concentration and methods of preparation of commonly used medication in ocular infection. Antibiotics Ceftazidime: It has a bactericidal and broad-spectrum activity. The bactericidal effect results from inhibiting mucopeptide synthesis in the bacterial cell wall. It is a semi-synthetic, thirdgeneration cephalosporin antibiotic, which is highly resistant to beta-lactamase and effective activity against gram-negative and some gram positive bacteria, particularly multi resistant strains of Pseudomonas Aeruginosa. Cefazolin: Cefazolin is a bactericidal broad-spectrum antibacterial agent. It belongs to first-generation cephalosporin and It acts by inhibiting the synthesis of the bacterial cell wall. Cefazolin is active against a wide range of bacteria, including the gram-positive cocci (except Enterococcus) and some gram-negative bacilli, such as E. coli, Proteus, and Klebsiella. However, there is a high prevalence of β-lactam resistance among gram- positive cocci. Vancomycin: Vancomycin is a semisynthetic member of beta-lactamase resistant penicillin’s, a tricyclic glycopeptide antibiotic. It act as bactericidal agent by inhibiting cell wall synthesis. It is effective against most Gram-positive bacteria including Streptococcus, Staphylococcus, and Bacillus species and not active against Gram-negative bacteria, fungi, or yeast. Tobramycin: Tobramycin is an aminoglycoside antibiotic which acts by inhibiting microbial protein synthesis. It has a broad spectrum of activity against Gram-negative bacteria, especially Pseudomonas aeruginosa. Tobramycin is physically incompatible with semisynthetic penicillin such as ampicillin. For this reason, the combination should never be mixed together in the same syringe or bottle for ophthalmic use. It is recommended that concomitant use is separated by 15 min. Gentamycin: Gentamicin is an aminoglycoside antibiotic which acts by inhibiting microbial protein synthesis. It is physically incompatible with semisynthetic Penicillin. Subconjunctival injection of gentamicin would be a poor choice due to its toxicity. It is effective against E. coli, Staphylococcus aureus, Enterobacter, Klebsiella, Serratia, Pseudomonas aeruginosa, and other gram negative bacteria resistant to less toxic antibiotics. Amikacin: Amikacin is an aminoglycoside antibiotic showing a broad-spectrum action and strong resistance against the enzymes inactivating the other aminoglycoside antibiotics. It is used in corneal ulceration caused by gram-negative bacteria which is resistant to gentamicin and tobramycin. Linezolid: It is active against most gram-positive bacteria such as streptococci, vancomycin- resistant enterococci, methicillinresistant staphylococcus aureus. Its acts by inhibiting the initiation of bacterial protein synthesis. Colistin: Colistin is a surface-active agent which penetrates into and disrupts the bacterial cell membrane. It interacts with the bacterial cytoplasmic membrane, changing its permeability, acting as bactericidal. It is indicated in multidrug resistant pseudomonas aeruginosa bacterial keratitis Imipenem-Cilastatin: Imipenem acts by inhibition of cell wall synthesis of various gram- positive, gram-negative bacteria and especially Enterococcus faecalis and Achromobacter xylosoxidans. Cilastatin blocks the activity of dihydropeptidase which prevents the breakdown of imipenem. Piperacillin/Tazobactam: Piperacillin/tazobactam is a betalactam/beta lactamase inhibitor with coverage against gramnegative organisms (including Pseudomonas aeruginosa), gram-positive organisms, and anaerobic bacterial organisms. Antifungals Amphotericin B: Amphotericin B injection is typically a complex of amphotericin B and deoxy-cholate with suitable buffers that form a colloidal dispersion when reconstituted. It binds to ergosterol in the fungal cell membrane, which leads to the formation of pores, ion leakage and ultimately fungal cell death. It is effective mainly against candida but has moderate activity against Aspergillus, Cryptococcus, Fusarium and Curvularia. Voriconazole: Voriconazole is a second-generation triazole antifungal agent and a synthetic derivative of Fluconazole with extended-spectrum antifungal activity. It presumably exerts its antifungal activity by inhibiting fungal cytochrome P450- dependent ergosterol synthesis resulting in a loss of ergosterol in the fungal cell wall. It is highly effective against Candida, Aspergillus, Fusarium, Paecilomyces, and Scedosporium species. Miconazole: Miconazole is a synthetic imidazole inhibits the synthesis of ergosterol, a major component of fungal cell membranes. It is effective against Paecilomyces, and Scedosporium species. Corneal Infections

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 56 Fluconazole: The mechanism of action is by blocking the synthesis of ergosterol, the primary sterol in the fungal cell membrane. It is effective against yeast, minimal activity against filamentous fungi. Natamycin: Natamycin inhibits the growth of fungi by specifically binding to ergosterol present in fungal cell membranes and alter its permeability. It is effective against fusarium, aspergillus and less effective against candida species. Antiprotozoals Chlorhexidine Digluconate: Chlorhexidine is a broad-spectrum biocide effective against Gram-positive bacteria, Gram-negative bacteria, acanthamoeba and fungi. Chlorhexidine inactivates microorganisms with a broader spectrum than other antimicrobials and has a quicker kill rate than other antimicrobials. The fungus uptakes chlorhexidine in a short amount of time1 and impairs the integrity of the cell wall and the plasma membrane entering the cytoplasm resulting in leakage of cell contents and cell death. It has both bacteriostatic and bactericidal, depending on its concentration. The mechanism of action for fungi is very similar to bacteria including bacterial spores and protozoa. Polyhexamethyl Biguanide: Polyhexamethylene biguanide (PHMB) is a synthetic compound with a broad-spectrum antimicrobial action and is considered as first line treatment of Acanthamoeba Keratitis. PHMB works by disrupting microbial cell membranes and metabolism, interfering with the function and destroying microbial cell. S. No Drug Name Mode of Administration Conc./Dosage Method of Preparation Shelf Life 1. Ceftazidime/ Cefazolin Fortified 5% (50 mg/ml) Add 10 ml of sterile solution to parenteral 500mg ceftazidime/ cefazolin powder 28 days Refrig. Intravitreal 2.25mg/0.1 ml Add 2 ml of sterile solution to 500 mg parenteral ceftazidime powder. Withdraw 0.1 ml drug solution and add 0.9 ml of sterile solution. 24 hrs. Intra Cameral 1mg/0.1ml Add 5 ml of sterile solution to 500 mg parenteral ceftazidime powder. Withdraw 0.1 ml and add 0.9 ml of sterile solution. 2. Vancomycin Fortified 50 mg/ml Add 10 ml of sterile solution to 500 mg of parenteral vancomycin 28 days Refrig. Intravitreal 1mg/0.1ml Add 10 ml of sterile solution to 500 mg of parenteral vancomycin. Withdraw 0.2 ml of drug solution and add 0.8ml of sterile solution. 24 hrs. Intra Cameral 1mg/0.1ml Same as above Subconjunctival 25mg/0.5ml Same as above 3. Tobramycin/ Gentamycin Fortified 14mg/ml Mix 2ml of tobramycin injectable solution (40mg/ml) to 5 ml of commercial solution of tobramycin ophthalmic solution (0.3%). 28 days Refrig. Intravitreal 1mg/0.1ml Add 10 ml of sterile solution to 500 mg of parenteral vancomycin Withdraw 0.2 ml of drug solution and add 0.8ml of sterile solution 24hrs Intra Stromal 0.06mg/0.02ml 0.02 ml of 0.3% commercially available solution Subconjunctival 20mg/0.5ml 0.5 ml of parenteral tobramycin solution 40 mg/ml Antibiotics Corneal Infections

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 57 S. No Drug Name Mode of Administration Conc./Dosage Method of Preparation Shelf Life 4. Amikacin Fortified 40mg/ml Parenteral formulation (80mg/2ml ampoules) can be used. 7 days Refrig. Intravitreal 0.125mg/0.1ml Add 0.9ml sterile solution to o.1ml parenteral amikacin (12.5mg/1ml) to make 12.5mg/ ml. Take 0.1 ml from prepared solution and add 0.9ml sterile solution to make 1.25mg/ml. 24 hrs. Subconjunctival 20-25mg/0.5ml 0.5 ml of Parenteral formulation (80mg/2ml ampoules) can be used. 5. Linezolid Fortified 2mg/ml 2mg/ml can be used directly from IV infusion 200mg/100ml. 34days 25*C Intravitreal 0.2 mg/0.1ml Inject 0.1 ml from parenteral solution 200mg/100ml. 24 hrs. 6. Colistin Fortified 1.9mg/ml 10ml of sterile solution added to parenteral colistimethate sodium powder (1million IU/75mg) to make 7.5mg/ml. withdraw 1ml solution mix with 3 ml of sterile solution wo make 0.19%. 1 day Refrig. Intravitreal 0.1mg/0.1ml Add 10 ml of sterile solution to parenteral colistimethate sodium powder (1million IU/75mg). 24hrs 7. Imipenem Cilastatin Fortified 10 mg/ml Add 10 ml of sterile solution to 500mg parenteral Cilastatin to make 50mg/ml. Withdraw 1ml and add 4ml of sterile solution to make 1%(10mg/ml). 2 days 2-8 *c Protect from light Intravitreal 0.05-0.1 mg/0.1 ml Add 100ml of sterile solution to parenteral imipenem 250mg powder Mix 0.2ml containing 0.5 mg with 0.3 ml sterile solution. 24 hrs. 8. Piperacillin/ Tazobactam Fortified 3.2mg/ml Add 20 ml of sterile solution to piperacillin- tazobactam 4.5 gm powder. Withdraw 4ml of this solution and add 10ml sterile solution. 14 days 4*C S. No Drug Name Mode of Administration Conc./Dosage Method of Preparation Shelf Life 1. Amphotericin Topical 0.15% Add 33ml of 5% dextrose to parenteral 50mg amphotericin powder. 7 days Refrig. Intra Cameral 5-10 mcg/0.1ml Add 10ml of Sterile solution to 50mg amphotericin colloidal vial. Withdraw 0.1 ml and add 9.9ml 24 hrs Antifungals Corneal Infections

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 58 S. No Drug Name Mode of Administration Conc./Dosage Method of Preparation Shelf Life 1. Chlorhexidine Digluconate Fortified 0.02% Add 5 mcl Chlorhexidine digluconate solution (20%) in 5ml of sterile solution using micropipette. 30 days 2-8*C 2. Polyhexamethyl Biguanide Fortified 0.02% Add 5mcl of PHMB solution (20%) to 5ml sterile solution using micropipette. 14 days Refrig. S. No Drug Name Mode of Administration Conc./Dosage Method of Preparation Shelf Life sterile solution. Withdraw 0.3 ml which contain 5mcg/0.1 ml. Intra Stromal 5 mcg/0.1ml Same as above Intravitreal Non-Liposomal 5 mcg/0.1ml Same as above Liposomal amphotericin B 10mcg/0.1ml Same as above 2. Voriconazole Topical 10mg/ml Add 20ml of sterile solution to 200mg voriconazole powder. 30 days Refrig. Intra Cameral 50mcg/0.1ml Add 19 ml of sterile solution 200 mg parenteral voriconazole powder Withdraw 1ml and mix with 9 ml sterile solution 0.05 ml solution contains 50mcg and add 0.05ml sterile solution to it. 24 hrs Intrastromal 50mcg/0.1ml Same as above Intravitreal 100 mcg/0.1ml Add 19 ml of sterile solution 200 mg parenteral voriconazole powder Withdraw 1ml and mix with 9 ml sterile solution 0.1 ml solution contains 100mcg. 3. Miconazole Subconjunctival 1.2-10mg/ml Subconjunctival injection of 1% commercially available miconazole solution. 24 hrs 4. Fluconazole Subconjunctival 2mg/ml Subconjunctival injection of commercially available fluconazole solution (0.2%). 24 hrs Intravitreal 25mcg/0.1ml Withdraw 1.25 ml of 0.2% commercially available fluconazole and mix with 8.75 ml sterile solution. 5. Natamycin (water soluble formNatasol) Intrastromal 10mcg/0.1ml Intrastromal (soluble form) natamycin prepared in ocular pharmacology, RP centre (patent pending and available on request of treating clinician). 24 hrs Antiprotozoals Corneal Infections

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 59 References 1. Extemporaneous Ophthalmic Preparations. S.L.: Springer. 2021. 2. Khanna V, Christy J, Jayarajan A, Chhabra K, Mishra K. A rare case of infectious crystalline keratopathy caused by Burkholderia cepacia. Indian Journal of Ophthalmology - Case Reports.2021;1(2):244. 3. Saluja G, Sharma N, Agarwal R, Sharma HP, Singhal D, Kumar Maharana P et al. Comparison of Safety and Efficacy of Intrastromal Injections of Voriconazole, Amphotericin B and Natamycin in Cases of Recalcitrant Fungal Keratitis: A Randomized Controlled Trial. Clinical Ophthalmology.2021;15:2437–2446. 4. Nixon H. Preparation of fortified antimicrobial eye drops. Kerala Journal of Ophthalmology.2018;30(2):152. 5. Samant P, Ramugade S. Successful use of intravitreal and systemic colistin in treating multidrug resistant Pseudomonas aeruginosa post-operative endophthalmitis. Indian Journal of Ophthalmology.2014;62(12):1167. Dr. Shweta Verma, MS Senior Resident, Department of Ophthalmology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India Corresponding Author: Corneal Infections

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 60 Calotropis Procera Latex Induced Keratopathy Aditi Ghosh Dastidar[1], MBBS, MS, FMRF, Deepika Khedia[2], MS, FMRF, Eesh Nigam[2], MS, FMRF, Monica Mukherjee[2], Optometrist 1. Cornea services, Synergy Eye Care, New Delhi, India. 2. Retina Services, Aditya Birla Sankara Nethralaya, Kolkata, India. Abstract: Accidental exposure to latex of Calotropis procera causes a spectrum of ocular toxicity and inflammation. Causative agents being the alkaloids present in the latex. We report a case of unilateral toxic keratitis in a female patient caused by accidental exposure to latex of Calotropis and its successful management. Introduction Calotropis procera is a xerophytic shrub of family Asclepiadaceae, with white to pink flowers.[1] In India, Calotropis flowers are used for worshipping Lord Shiva and in ayurvedic medications. Accidental exposure of eyes to latex splash while plucking the flower is common. Alkaloids present in latex cause ocular inflammation and toxicity. We report a case of successful management of Calotropis latex induced keratopathy. Case A 40 year old female, presented to our services with unilateral, painless, gradual diminution of vision associated with redness, watering and initial photophobia after accidental inoculation of latex of Calotropis in left eye by splash during plucking of Akanda flower , few hours back. There was no history of previous herpes infection, trauma, surgery, any ophthalmic disorder and no significant systemic disease. On examination, best corrected visual acuity (BCVA Snellen’s) was 6/60 in left eye and 6/6 in right eye. Slit lamp examination of left eye revealed conjunctival congestion, intact corneal epithelium, stromal oedema, Descemet membrane (DM) folds, mild anterior chamber reaction and clear lens (Figure 1A and 1B). Right eye was normal. Both eyes intraocular pressure was 12mm Hg. Both eye fundus examination was normal. Specular microscopy showed no countable cells in left eye due to corneal oedema and 2432 cells/mm2 in right eye (Figure 2 A and 2 B). Corneal pachymetry was raised 624 micron in left eye and 511 microns in right due to corneal edema. Diagnosis of left eye acute toxic keratitis due to latex was made. Thorough wash with Ringer’s lactate solution was given. Patient was started on topical steroid (Prednisolone acetate 1%) 6 times/day (weekly taper), antibiotic eye drop 6 times/day, carboxy-methylcellulose sodium (preservative free) 6times/ day, cycloplegic 2 times/day, sodium chloride (5%) eye drop 4 times/day and (6%) eye ointment once at night. After first week, symptoms improved and BCVA 6/24 was noted. At 4 weeks follow-up, BCVA was 6/6 in both eyes with resolution of keratopathy (Figure 2 A and 2 B). Left eye specular microscopy showed 2412 cells/mm2 cell density and morphology comparable to right eye(Figure 3 C and D) and pachymetry of 514 microns. Patient maintains her vision at 1 year follow up. Figure 1: Slit lamp photograph of Left eye on presentation, 1 day after accidental latex splash from Calotropis flower, Fig 1 A(diffuse view) and 2B (slit view) showing intact corneal epithelium, stromal edema (yellow arrow), Descemet membrane folds (red arrow). Inflammation and Cornea

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 61 Discussion Calotropis procera or Akanda flower (Figure-4) latex contains ‘Caustic Alkaloid’ agents namely Calotropin and Calotoxin, which cause ocular toxicity. Histamine and prostaglandin present in the sap causes iridocyclitis and secondary glaucoma, not seen in our case.[2,3,7,8] Anaesthetic property of latex is attributable to painless and delayed presentation of patient.[5] Corneal endothelium is main site of latex toxicity rather than epithelium, resulting in rapid stromal oedema with an intact epithelium as seen in our case.[3,6] Decrease in endothelial count and change in morphology has been documented, making specular microscopy a must.[3,9] In our case on resolution, endothelial cell count and morphology was comparable with unaffected eye. Cases are treated as acute chemical injury and toxic keratitis with copious irrigation, steroids, antibiotic, lubricants, hyper osmotic agents, cycloplegics and anti glaucoma medication.[4,6] Use of Calotropis flower for worship and indigenous medicine is common practice in India. Accidental exposure to eye and skin Figure 2: Slit lamp photograph of left eye,after 4 week of treatment and resolution of signs and symptoms, Fig 2A (diffuse view) and Fig 2B (slit view) depicts resolved latex keratopathy, with clear cornea, no corneal oedema and quiet anterior chamber. Figure 3A and B: Specular microscopy prior (3A) and post (3B) treatment in left eye respectively. can be prevented by using protective glasses, avoid direct contact and hand washing. This highlights need of public awareness for prevention of contact to latex, its side effects and need of urgent medical aid. Figure 4: Calotropis Procera (Akanda Flower) white to pink flowers. Inflammation and Cornea

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 62 References 1. Al Ghadeer H, Al Gethami A, Al Sulaiman H, et al. Corneal toxicity after self-application of Calotropis procera (Ushaar) Latex: Case report and analysis of the active components. Middle East Afr J ophthalmology 2019; 26: 40- 42. 2. Basak SK, Bhaumik A, Mohanta A, et al. Ocular toxicity by latex of Calotropis procera (Sodom apple). Indian J ophthalmol 2009; 57: 232- 234. 3. Waikar S, Srivastava VK. Calotropis induced ocular toxicity. Med J Armed Forces India 2015; 71: 92- 94. 4. Pandey N, Chandrakar AK, Garg ML, et al. Calotropis procera-induced keratitis. Indian J ophthalmol 2009; 57: 58-60. 5. Muthayya RE. Madar keratitis. Proc Indian Ophthalmic Soc 1949; 10: 44- 47. 6. Lakhtakia S, Dwivedi PC, Choudhary P, Chalisgaonkar C, Rahud J. Ocular toxicity of Calotropis - missing links. Indian J Ophthalmol. 2010;58:169. 7. Kumar V.L., Shivkar M.Y. Involvement of prostaglandins in inflammation induced by latex of Calotropis procera. Mediators Inflamm. 2004;13:151–155. 8. Shivkar M.Y., Kumar V.L. Histamine mediates the proinflammatory effect of Calotropis procera in rats. Mediators Inflamm. 2003;12:299– 302. 9. Al-Mezaine H.S., Al Rajhi A.A., Al-Assiri A., Wagoner M.D. Calotropis procera (ushaar) keratitis. Am J Ophthalmol. 2005;391(1):199– 202. Dr. Aditi Ghosh Dastidar, MBBS, MS, FMRF Cornea services, Synergy Eye Care, New Delhi, India. Corresponding Author: Inflammation and Cornea

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 63 Perspective on Keratopigmentation: The Traditional and The Novel Uses Garvita Dabas, MBBS, MS, Kanika Bhardwaj, MBBS, DNB, Krishna Teja Boggarapu, MBBS, MS, Yuganki Kush, MBBS, MS, Isha Chaturvedi, MBBS, MS, Tulika Chauhan, MBBS, MS, FICO Centre For Sight Eye Institute. Introduction Keratopigmentation (KTP) commonly known as Corneal tattooing is a unique procedure that is used to enhance the appearance of a disfigured or scarred cornea to make it cosmetically acceptable. Keratopigmentation is a centuries old procedure and with constant modifications in techniques has stood the test of time. The implications are not esthetical but also psychological. History of KTP The recorded history of KTP dates back to ancient Greek times from 131-210 AD when Galen, a physician first corrected corneal opacity using reduced Copper Sulphate.[1] A similar technique is documented to have been performed in 450 AD where anterior corneal surface was cauterised and dye constituted from powdered nutgalls, ferric tannate or pulverized pomegranate bark mixed with a copper salt was directly applied to the cauterized surface.[2] In 1869, Louis Von Wecker coated the cornea with a thick layer of India Ink after anaesthesia with Cocaine. The corneal surface was the then punctured multiple times to deposit the pigment in the corneal tissue. This led to the advent of the puncture technique of KTP.[3] The idea of a fountain pen inspired Nieden in 1901 to design a tattooing needle.[4] In recent times, due to advances in ophthalmology the procedure of KTP has become a safe day-care procedure that is commonly performed for therapeutic and cosmetic reasons with high patient satisfaction. In this paper, we like to bring attention to the novel applications of Keratopigmentation around the world. Techniques of Keratopigmentation The pigment may be impregnated superficially (superficial manual and superficial automated KTP) or intrastromal (manual intralamellar KTP and FLAK). There are four main techniques performed commonly1. Manual intralamellar KTP (MIK) 2. Superficial manual KTP (SMK) 3. Superficial automated KTP (SAK) 4. Femtosecond laser assisted KTP (FAK) Apart from these, other techniques reported in literature include small-incision lenticule extraction based KTP, superficial corneal staining, intralamellar corneal staining, multiple noncontinuous trans-epithelial puncture technique, flap-based tattooing techniques and femtosecond assisted anterior lamellar corneal tattoo.[5] Various advantages and disadvantages are seen with the methods above. The manual impregnation of cornea with the pigment was one of the earliest methods, but in this method, the staining achieved by the pigment dye is non uniform thus deeming it as an unreliable technique. In the stromal puncture technique, the risk of corneal perforation in thin scarred areas of the cornea coexists with a lack of uniform dye distribution. Manual lamellar keratectomy or femtosecond laser assisted techniques offers the advantage of dye spreading homogenously and more satisfactory visual results. The process involves creation of a potential space in the stromal layer and depositing the pigment into this pocket. Figure-1 shows KTP technique using creation of intrastromal tunnel pocket. Femtosecond laser assisted procedure drastically improves the ease and speed of procedure. However, it is ineffective in cases of corneal scars[6] and is a tad bit expensive, not to mention the lack of common availability of femtosecond lasers. Figure 1: A) creation of intrastromal tunnel. B) Impregnation of the pocket with pigment. Picture Courtesy Dr. Tulika Chauhan & Dr. Roberto Pineda II (MEEI, University of Harvard) Commom Indications of KTP The common indications for performing corneal tattooing are cosmetic and therapeutic like • Cosmetic correction of corneal scars in patients who are intolerant to cosmetic contact lenses, • Adherent leucomas, • Total or partial iris defects, • Albinism, • Aniridia, • Iridodialysis • Iris atrophies after trauma or anterior segment surgery. Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 64 These indications are also associated with numerous visual disabilities in the patient such as monocular diplopia, severe glare, halos or photophobia.[7] They can also result from peripheral iridotomies, and congenital defects, such as albinism or essential iris atrophies. The management of symptoms in the above listed pathologies can be easily done with keratopigmentation.[8] While traditional indications have been known for ages, there are now many new areas where KTP has been gaining popularity specially the esthetic and cosmetic indications that have become popular in the recent times with increasing awareness of one’s external appearance and the desire to influence and be influenced through social media. The following text describes such new uses of KTP in and around the eyes. Novel Indications of KTP 1. URRETS-ZAVALIA SYNDROME: A study in 2012 studied the use of Keratopigmentation in post-traumatic eyes with a fixed dilated pupil. In this report, traumatic iridoplegia was complicated by presence of an anterior chamber phakic Intra-ocular Lens (ACIOL) causing iris atrophy, also known as Urrets-Zavalia syndrome, resulting in the patient complaining of incapacitating photophobia and glare. Femtosecond-assisted double-pigmented layer KTP technique was used to successfully treat these patients.[6] 2. COSMETIC CHANGE OF EYE COLOR: There is a large percentage of the population that wishes to either change or enhance their eye colour.[9] This replacement of genetically determined iris colour with a cosmetically variable color in keeping with the patient’s preferences can be done with various methods such as • Cosmetic keratopigmentation. • Cosmetic colored contact lenses. • Colored iris silicone diaphragm which is an intraocular diaphragm implanted in front of the iris to mask its color and give an impression of a different iris colour. • Laser iris depigmentation using a frequency-doubled 532- nm wavelength neodymium: yttrium–aluminium–garnet (Nd:YAG) laser with variable spot size Cosmetic contact lenses are a viable temporary measure to give better appearance (refer to Figure-2) but are prone to complications such as corneal infection, giant papillae on eye lid, abrasions, the induction of dry eye syndrome rendering the patient intolerant for prolonged or permanent use.[10] Figure 2: A) Right eye with leukocoria, B) Cosmetic contact lens masking leukocoria. Figure 3: Cosmetic iris implant diaphragm. A) appearance of hazel colored implant in eye. B) Removal of implant showing underlying pupillary abnormality. C) Explanted Cosmetic iris implant. Picture Courtesy Dr. Tulika Chauhan & Dr. Roberto Pineda II (MEEI, University of Harvard) Cosmetic iris implants such as intraocular diaphragm can also be implanted in front of the iris to mask its color and give an impression of a different iris colour, (Figure-3) but it is associated with complications like risks of intraocular infection and chronic iritis due to continuous rubbing of iris and release of pigments and inflammation.[11] Cosmetic iris implants are not yet FDA approved or CE-marked however they remain popular due to cosmetic demands worldwide.[12] Out of all the above options, KTP has proven to be a time tested and extensively studied procedure. The level of evidence available suggests that cosmetic keratopigmentation is the best evidencesupported surgical choice for patients seeking a permanent cosmetic eye color change.[12] Still, additional investigation is needed to optimize the outcomes, minimize postoperative complications and further develop this and other new surgical alternatives. It is hence a popular technique even for cosmetic change of the color of the seeing eyes for selective patients with minimal complications and high patient satisfaction. 3. COMBINED WITH PTERYGIUM/PSEUDOPTERYGIUM EXCISION: In a patient with pre-existing corneal opacity with pterygium/ pseudopterygium in an eye with no visual potential, cosmetic rehabilitation can be done with KTP. In a study conducted at R P Centre AIIMS, New Delhi, India in 2021, Corneal tattooing was augmented with modified head inversion pterygium surgery for cosmetic rehabilitation in five patients. This was especially applicable for eyes with limbal stem cell deficiency or large pterygia where conjunctival autograft was not advisable. At 6 months follow up no complications were reported and also the cosmetic rehabilitation was excellent in all patients.[13] 4. SQUINT SURGERY: Eyes which are PL negative often have dense corneal opacities, band shaped keratopathy and corneal scars. They consequently develop strabismus which worsens the cosmetic appearance of the eye. KTP has evolved over time and can be potentially used as an adjuvant to squint correction surgeries. A study by Balgos et al combined keratopigmentation (KTP) with strabismus surgery in 73 eyes and proved it to be an innovative option with good cosmetic outcomes and high patient satisfaction.[14] 5. PIGMENT USE IN EYE OTHER THAN THAT ON CORNEA: (Figure-4) Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 65 Figure 4: Cosmetic Permanent Tattoos. A) scleral tattooing, B) Permanent Eyeliner, C) Microblading of eyebrows. Picture courtesy: Wikipedia • SUB-CONJUNCTIVAL/EPISCLERAL PIGMENTATION:[15] Eyeball tattooing is also a new form of cosmetic body modification involving tattooing of the entire white sclera surrounding the cornea (Figure-4A). It is usually practiced by untrained tattoo professionals. Various complications like post procedure headaches, eye pain, photophobia and persistent foreign body sensation are frequently seen. Major complications include globe penetration along with the risk of endophthalmitis and orbital cellulitis. Ink related complications include hypersensitivity reaction, migration of the ink coating the lens, corneal endothelium, and trabecular meshwork. This may lead to the development of foreign body granulation reactions, uveitis, secondary glaucoma. • PERMANENT EYE LID TATTOOING (PERMANENT EYELINER):[16] Another beauty trend is to get permanent eyeliner inked on the lash line in order to give the appearance of larger eye apertures. Patients receive pigmentation on the skin along the lashes of upper eyelid (Figure-4B). These eyeliner tattoos are a recent addition to the advent of permanent makeup. Most common complication includes allergic granulomatous reaction which may require systemic steroid for treatment. • MICROBLADING:[17] It is a method of semipermanent eyebrow tattooing where pigment is deposited along hair follicles of the eyebrows giving them a fuller look (Figure-4C). This procedure is also done under the umbrella of permanent makeup and cosmetic tattooing by non-ophthalmic tattoo artists. Complications include redness, swelling, crusting, or pigment oozing. Reaction to the coloring pigment or contamination of the pigment is also possible. • UNDER EYE TATTOO TO CONCEAL UNDER EYE DARK CIRCLES:[18] Also known as cosmetic tattooing, permanent concealer, or micropigmentation, this unique procedure involves use of tiny needle that add a layer of pigment over the under-eye skin to camouflage hyperpigmentation or scarring. These tattoos change colour and even fade over time due to normal skin cell turnover and sun exposure. Other complications can include swelling, bruising or allergic reaction to pigment. Types of Pigments Used Presently, pigments offering assorted colors that have CE mark (Conformitѐ Europѐene) are available worldwide and due to their proven safety, have been approved for their use in KTP. Many surgeons also use FDA (Food and drug administration, USA) approved sterile dyes and inks used in skin tattooing. On January 4, 2022, under the REACH regulations (Registration, Evaluation, Authorization and Restriction of Chemicals), restrictions were introduced for tattoo inks and pigments.[19] However, these regulations did not apply on mixture used for tattooing purposes marketed exclusively as a medical device or an accessory to a medical device.[20] In a study published in India in 2021, intra-operatively selfprepared carbon soot from candle flame was used to impregnate the cornea with very satisfactory results.[21] Properties of an Ideal Pigment An ideal pigment should have certain properties as listed below: [2] 1. They should provide a good cosmetic result. 2. The colors should stay fixed in place 3. There should be minimal modification occurring in cornea. 4. There should be least dispersion of pigment particles 5. They should not incite an immunological reaction. 6. They should cause no toxicity 7. They should not fade with time. Commercially available tattoo pigments are listed below: S. No Pigment Name Company Name Country Name Medical Approval Colour 1. BioChromaEyes Laboratoires BIOTIC Phocea Spain European certification as a CE class IIb medical device, all common iris colours like brown, snow, honey, ebony, anthracite, chocolate, hazelnut, water green, lagoon, emerald, green, ocean, pistachio Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 66 S. No Pigment Name Company Name Country Name Medical Approval Colour 2. India ink powdered Mahatme laboratories India Black 3. Coloured Tattoo ink Intenze Products, Inc., Rochelle Park, NJ, USA FDA approved Available in all colours Complications While Keratopigmentation of cornea has been a tried and tested procedure in use from centuries ago, it is not immune to complications. The novel uses are specially practised by non-medical professionals in the name of tattoo artists and are largely unaware of the entailing complications which can be vision threatening. The complications associated with KTP can be broadly classified as those due to the technique, toxicity to the material of the pigment, and those due to functional complications. Figure 5: Fading of pigment seen three months after Keratopigmentation. Functional complications- Visual field limitation and light sensitivity are common functional complaints post KTP. In a comprehensive review of 234 eyes that had undergone KTP, only 12.82% of patients complained of any complication. The most common complaint was post procedure light sensitivity (49%) Technique related complications[22]- inadvertent puncture of the globe, conversion to keratoplasty is not so uncommon. Undesirable migration of the pigment can also occur. Pigment Related Complications- The dye pigments are insoluble in water; hence, their toxicity potential is low but not nil. Various published case reports document rare findings of iridocyclitis, non-healing corneal epithelial defects, corneal ulceration, and granulomatous keratitis up to 3 weeks after KTP.[23] Fading of pigment is marked with the superficial impregnation technique (refer to Figure-5). which resolved on its own in 81.81% patients within six months postoperatively.[20] There is also the concern regarding interference of pigments leading to MRI alterations. It has been suggested in many studies Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 67 Conclusion The advances in ophthalmology have resulted in drastic improvements in the pigment, the procedure, and the applications of corneal tattooing. KTP has stood the test of time and has proved its utility in various conditions. The available level of evidence suggests that cosmetic Keratopigmentation is the best evidence-supported surgical choice for those seeking a more permanent eye color change cosmetically.[12] However, one should be careful in selection of suitable candidates as well as be highly aware of the possible complications of the procedure in order to provide their patients with best possible care, an added confidence and complete satisfaction. No Financial Disclosure References 1. Holth: Revival of Galen’s corneal staining with... - Google Scholar [Internet]. [cited 2022 Dec 10];Available from: https://scholar. google.com/scholar_lookup?journal=Am+J+Ophthalmol&title=Revival+of+Galen%E2%80%99s+corneal+staining+with+coppersulfate+and+tannine+should+be+abandoned&author=S+Holth&volume=14&publication_year=1931&pages=378-9& 2. Ziegler SL. Multicolor Tattooing of the Cornea. Trans Am Ophthalmol Soc 1922;20:71–87. 3. Roy JN. TATTOOING OF THE CORNEA *. Can Med Assoc J 1938;39(5):436–8. 4. Alsmman Hassan AH, Abd Elhaliem Soliman NGE. Intrastromal Injection of China Painting Ink in Corneas of Male Rabbits: Clinical and Histological Study. J Ophthalmol 2016;2016:8145926. 5. Hasani H, Es’haghi A, Rafatnia S, Alilou S, Abolmaali M. Keratopigmentation: a comprehensive review. Eye (Lond) 2020;34(6):1039–46. 6. Alio JL, Rodriguez AE, Toffaha BT, El Aswad A. Femtosecond-assisted keratopigmentation double tunnel technique in the management of a case of Urrets-Zavalia syndrome. Cornea 2012;31(9):1071–4. 7. Ricardo JR da S, Medhi J, Pineda R. Femtosecond laser-assisted keratopigmentation for the management of visual disabilities due to peripheral iridectomies. J Glaucoma 2015;24(4):e22-24. 8. Alio JL, Rodriguez AE, Toffaha BT. Keratopigmentation (corneal tatthat heavy metals in pigments, such as iron led to changes in local magnetic field in MRI that distort the image of the globe. Some patients have also reported mild pain while undergoing MRI in less than 3 months after KTP.[7] However, another study upon 135 subjects who had undergone permanent cosmetics reported tingling and burning sensation in only 2 of the subjects and concluded that no serious soft tissue reactions or adverse events were recorded during MRI.[24] Surgical Technique Related Complication Pigment Related Complication Functional Complication Corneal perforation Toxicity of pigment Limitation of visual field Recurrent erosions Durability of pigment Sensitivity to light Pigment non-homogeneity Alteration in colour of pigment over a prolonged period of time MRI alterations Microbial infection Undesirable migration of pigment Corneal vascularisation and oedema Dye leakage into the conjunctival space or anterior chamber Fading of the pigment over time Light sensitivity tooing) for the management of visual disabilities of the eye related to iris defects. Br J Ophthalmol 2011;95(10):1397–401. 9. Al-Shymali O, Rodriguez AE, Amesty MA, Alio JL. Superficial Keratopigmentation: An Alternative Solution for Patients With Cosmetically or Functionally Impaired Eyes. Cornea 2019;38(1):54–61. 10. Chalmers R. Overview of factors that affect comfort with modern soft contact lenses. Cont Lens Anterior Eye 2014;37(2):65–76. 11. Garcia-Pous M, Udaondo P, Garcia-Delpech S, Salom D, Díaz-Llopis M. Acute endothelial failure after cosmetic iris implants (NewIris®). Clin Ophthalmol 2011;5:721–3. 12. D’Oria F, Abu-Mustafa SK, Alio JL. Cosmetic Change of the Apparent Color of the Eye: A Review on Surgical Alternatives, Outcomes and Complications. Ophthalmol Ther 2022;11(2):465–77. 13. Bafna RK, Kalra N, Sinha R. Modified head inversion technique for pterygium and pseudopterygium surgery combined with keratopigmentation. Eur J Ophthalmol 2021;31(3):1426–30. 14. Balgos JD, Amesty MA, Rodriguez AE, Al-Shymali O, Abumustafa S, Alio JL. Keratopigmentation combined with strabismus surgery to restore cosmesis in eyes with disabling corneal scarring and squint. Br J Ophthalmol 2020;104(6):785–9. 15. Eye Tattooing - EyeWiki [Internet]. [cited 2022 Dec 10];Available from: https://eyewiki.aao.org/Eye_Tattooing 16. Vagefi MR, Dragan L, Hughes SM, Klippenstein KA, Seiff SR, Woog JJ. Adverse reactions to permanent eyeliner tattoo. Ophthalmic Plast Reconstr Surg 2006;22(1):48–51. 17. Long Term Effects of Microblading Eyebrows to Consider Before You Commit | Allure [Internet]. [cited 2022 Dec 10];Available from: https://www.allure.com/story/microblading-long-term-effects 18. Yes, You Can Now Tattoo Away Dark Circles — But Should You? 9 FAQs [Internet]. [cited 2022 Dec 10];Available from: https://www. healthline.com/health/body-modification/under-eye-tattoo 19. Tattoo inks and permanent make-up - ECHA [Internet]. [cited 2022 Dec 10];Available from: https://echa.europa.eu/hot-topics/tattoo-inks 20. Tattoo inks and permanent make-up pigments: new restrictions - Obelis Group [Internet]. [cited 2022 Dec 10];Available from: https:// www.obelis.net/news/tattoo-inks-and-permanent-make-up-pigments-new-restrictions/ Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 68 21. Ravindra MS, Meda DR. A novel indigenous technique for corneal tattooing using self-prepared do-it-yourself carbon soot pigment. Indian Journal of Ophthalmology 2021;69(9):2516–20. 22. Segal L, Choremis J, Mabon M. Intrastromal corneal tattooing for symptomatic iridotomies. Br J Ophthalmol 2012;96(3):464–5. 23. Sharma A, Gupta P, Dogra MR, Hidayat AA, Gupta A. Granulomatous Keratitis following Corneal Tattooing. Indian Journal of Ophthalmology 2003;51(3):265. 24. Tope WD, Shellock FG. Magnetic resonance imaging and permanent cosmetics (tattoos): survey of complications and adverse events. J Magn Reson Imaging 2002;15(2):180–4. Dr. Tulika Chauhan, MBBS, MS, FICO Centre For Sight Eye Institute, New Delhi. Corresponding Author: Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 69 Refractive Options in High Myopia Mayur Jain, MS, Neha Kapur, DNB, MNAMS, FSCEH Cornea department, Dr Shroff’s Charity Eye Hospital. Abstract: High myopia is defined as myopia equal to or more than -5 dioptres (D) more of spherical correction. There is a growing trend among myopes towards opting for options other than wearing glasses, more so in high myopes for cosmetic issues as well as image clarity with high-power glasses. In this excerpt, we shall aim to discuss various refractive modalities in high myopes, highlighting the advantages and disadvantages of each. High myopia is defined as myopia equal to or more than -5 dioptres (D) of spherical correction.[1,2] The prevalence of myopia is increasing globally.[3] It has been predicted that, by the year 2050, high myopia will affect 9.8% of the global population.[4] Thus the need for refractive correction in high myopic eyes is also ever-growing. Various options for refractive error correction in high myopia include: In this excerpt, we shall be discussing each of these options in detail. Spectacles Spectacles are the first modality of refractive correction resorted to. The various disadvantages of glasses in high myopia are lesser accommodation and convergence, peripheral image duplication, and myopic rings. To address the concerns of increased edge thickness of high power spectacle lens, increase in the refractive index of the lens and reducing the optical aperture are modifications, hence making the spectacles more aesthetic. Contact Lens Contact lenses are a great visual rehabilitation option in patients with high refractive error. Particularly individuals unwilling to undergo any refractive surgery or unsuitable for the same can be greatly benefited from contact lenses. They can be prescribed as either daily disposable or planned replacement contact lenses, depending upon the patient’s preferences and maturity. Orthokeratology for reducing the progression of myopia is gaining acceptance in up to 16 years of age with spherical correction of up to -8D of sphere and -1.5D of cylindrical correction.[5] MiSight is a soft contact lens which also reduces myopia progression. It is an FDA-approved soft contact lens with a central zone with a distance correction and concentric peripheral zones alternating myopic defocus with distance correction.[6] LASIK LASIK is the most common refractive surgery worldwide.[7] Depending on the platform, current FDA approvals for LASIK allow treatment of myopia up to -14.00D, astigmatism up to 6.00D, and hyperopia up to 6.00 D.[8] Although very safe in mild to moderate myopia, LASIK has its own limitations in high myopia. Most surgeons are apprehensive of performing LASIK in more than -10D of myopia due to concerns of regression, insufficient tissue for primary ablation and retreatments, the deranged optical quality of vision and risk of post-LASIK ectasia.[9,10] Femtosecond LASIK has a definite advantage over microkeratome LASIK due to the creation of a thinner flap. Maintaining a safe residual stromal bed and considering the percentage of tissue ablated are important parameters in the planning of refractive correction. However, the risk of regression with both procedures cannot be overlooked. Feng Z. et al in their study concluded that Corneal Higher Order Aberrations (HOAs) including coma and spherical aberration increased significantly after Femtosecond LASIK surgery in high myopia. The greater the ablation depth, the larger the influence on spherical aberrations.[10] However, Wallerstein et al. concluded that very high myopia with refractive errors between -10 and -13D also fared very well in terms of visual outcomes and quality of vision with the newer generation lasers.[9] Topographic-guided ablation utilizing the topography-measured refraction for correction of myopia has FDA approval for usage up to -8D of myopia and -3D of astigmatism with better optical quality and reduction of night glare and haloes.[11] Surface Ablation Surface ablation techniques including PRK and Trans PRK may also be considered in high myopia. Gershoni et al concluded predictable and good visual outcomes in high myopia (spherical equivalent of -7.87+/- -1.46) with trans-PRK in 674 eyes. 8.16% Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 70 of cases had clinically apparent postoperative haze. Thus, most studies advocate good outcomes post PRK with up to -6D to -6.5D of spherical equivalent.[12] Small Incision Lenticule Extraction (SMILE) Small incision lenticule extraction (SMILE) is a femtosecond laser refractive procedure in which a corneal stromal lenticule is created and removed through a small incision to correct the refractive error.[13] It thus preserves corneal integrity better than LASIK eliminating the flap-related risks and complications of LASIK.[14,15] SMILE is, therefore, safer than LASIK as well as not associated with flap-related complications such as dry eye, among other advantages.[13,16] Another advantage is that it is an all-in-one femtosecond laser–assisted treatment for myopia that can be performed by just one femtosecond laser system instead of the two (femtosecond and excimer laser systems) in LASIK. It can be used to correct high myopia up to -10.00D.[17] According to various studies, SMILE results in less undercorrection, less regression, and a smaller increase in spherical aberrations when compared to Femtosecond LASIK, resulting in better visual outcomes in high myopia patients.[17,18] However, a systematic review and meta-analysis by Cao et. Al comparing ICL and SMILE in high myopia concluded that Compared to SMILE, ICL implantation showed a better efficacy index and better safety index. Although ICL implantation showed a higher risk of halos, but higher-order aberrations were lesser in ICL patients post-operatively. Overall, ICL implantation might be a better choice for high myopia correction in adults.[19] Hamed AM et al. conducted a study on 282 eyes to evaluate various intraoperative complications with the procedure. The intraoperative complications included lost vacuum (18 eyes, 6.38%), treatment decentration (6 eyes, 2.12%), wound bleeding (21 eyes, 7.45%), incomplete bubble separation (black islands) (3 eyes, 1.06%), the epithelial defects (15 eyes, 5.32%).[20] Implantable Collamer Lens (Figure-1) This procedure was first performed in 1993, and got US FDA approval in 2005.[21] ICL is a plate-haptic single-piece IOL which is composed of 0.14% collagen, hydroxyethyl methacrylate (hydrophilic acrylic copolymer) with an ultraviolet light– filtering chromophore. The lens is implanted in the posterior chamber, behind the iris and in front of the lens. It corrects myopia as well as astigmatism. One of the commonly used ICLs, The Visian ICL is FDA-approved for myopia between -3.00 to -20.00D. IPCL V2.0, another commonly used ICL by the Care group is available from 0 to -30.00D for myopia correction. ICL has a central hole utilising the centraFLOW technology, ensuring aqueous drainage and eliminating the need for a PI. This hole is 380 microns in size ensuring minimal light scattering and thus reducing visual disturbances. ICL has no minimum corneal thickness requirement, in contrast to LASIK and PRK. But it does have a minimum Anterior Chamber Depth (ACD) requirement, which is 2.88mm. (3mm in Visian ICL). The advantage of ICL over LASIK includes fewer induced higher-order aberrations and improved postoperative contrast sensitivity.[22] ICL implantation has shown a low and non-progressive endothelial cell loss over time (5.5% at 2 years).[23] Induced cataract has been reported between 1% and 7%, although some authors found lens opacities in 14.5%.[23] Pigmentary dispersion syndrome has been reported in 2.2% of eyes at 12 months after ICL implantation, although true pigmentary glaucoma is rare. Other complications include pupillary block and malignant glaucoma, and ICL decentration. Figure 1: ICL Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 71 Clear Lens Extraction Spectacles Clear lens extraction replaces the crystalline lens in the myopic eye with an IOL of a power that neutralises the myopic error of the eye. Monofocal intraocular lenses are the preferred lens used in this procedure, mandating the need for near-vision glasses postoperatively. Multifocal intraocular lenses are usually not a preferred option as these highly myopic eyes may be predisposed to retinal areas of weakness, which may require surgical procedures needing oil or gas which may worsen the quality of vision postoperatively. Monovision, in which one eye is made emmetropic while the other eye (non-dominant eye) is left slightly myopic to ensure a better range of vision, is another practical modality. Clear Lens Extraction is a more predictable and stable procedure with a larger range of refractive correction possible than with either LASIK or phakic IOL. Also, it is more cost-effective, as the higher cost of phakic IOLs and future cataract surgery is eliminated. Indications of CLE include - 1. High myopia patients are not amenable to conventional LASIK because of high refractive error or thin cornea. 2. High myopes are not amenable to phakic IOL because of low anterior chamber depth, poor endothelial counts, or early cataract changes 3. Presbyopic high myopic patients who want reasonable independence from glasses for both distance and near vision using Monovision or multifocal IOLs. 4. Myopes with early lens changes who desire refractive correction. Alsmann A. et al in their study comparing ICL with CLE concluded that there was no difference between the two procedures in the management of high myopia but recommended minimizing the use of the CLE with young patients to early avoid loss of the accommodation.[24] There is thus a plethora of options available to patients today for correction of high myopia. A case-to-case analysis based on the patient’s visual requirement, occupation, financial constraints and compliance with follow-up can help them achieve the maximum visual potential. References 1. The Eye Diseases Prevalence Research Group. The Prevalence of Refractive Errors Among Adults in the United States, Western Europe, and Australia. Archives of Ophthalmology. 2004;122:495–505. 2. Pan CW, Ramamurthy D, Saw SM. Worldwide prevalence and risk factors for myopia. Ophthalmic Physiology and Optics. 2012;32(1):3– 16. 3. Dolgin E. The myopia boom. Nature.2015;519(7543):276–8. 4. Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, et al. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036– 42. 5. Lee YC, Wang JH, Chiu CJ. Effect of orthokeratology on myopia progression: twelve-year results of a retrospective cohort study. BMC ophthalmology. 2017 Dec;17(1):1-8. 6. Chamberlain P, Peixoto-de-Matos SC, Logan NS, Ngo C et al. A 3-year Randomized Clinical Trial of MiSight Lenses for Myopia Control. Optometry and Vision Science. 2019; 96(8):556-7. 7. Kohnen T, Strenger A, Klaproth OK. Basic knowledge of refractive surgery: correction of refractive errors using modern surgical procedures. Dtsch Arztebl Int. 2008 Feb;105(9):163-70. 8. El Bahrawy, Mohamed & Alió, Jorge. (2015). Excimer laser 6 generation: state of the art and refractive surgical outcomes. Eye and Vision. 2. 10.1186/s40662-015-0015-5. 9. Wallerstein, A., Kam, J.W.K., Gauvin, M. et al. Refractive, visual, and subjective quality of vision outcomes for very high myopia LASIK from −10.00 to −13.50 diopters. BMC Ophthalmol 20, 234 (2020). 10. Feng Z, Wang Q, Du C, Yang F, Li X. High-order aberration changes after femtosecond LASIK surgery in patients with high myopia. Ann Palliat Med. 2021 Jul;10(7):7689-7696. 11. Motwani M. Treatment of high myopia/myopic astigmatism with a combination of WaveLight Contoura with LYRA protocol and wavefront-optimized treatment. Clin Ophthalmol. 2018 May 10;12:875- 883. 12. Gershoni A, Mimouni M, Livny E, Bahar I. Z-LASIK and Trans-PRK for correction of high-grade myopia: safety, efficacy, predictability and clinical outcomes. Int Ophthalmol. 2019 Apr;39(4):753-763. 13. Kobashi H, Kamiya K, Shimizu K. Dry Eye After Small Incision Lenticule Extraction and Femtosecond Laser–Assisted LASIK: Meta-Analysis. Cornea 2017;36:85-91. 14. Mrochen M, Donitzky C, Wullner C, Loffler J. Wavefront-optimized ablation profiles:theoretical background. J Cataract Refract Surg 2004; 30:775–785. 15. Xia LK, Ma J, Liu HN, Shi C, Huang Q. Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism. Int J Ophthalmol 2018;11:470-77. 16. Moshirfar M, Murri MS, Shah TJ, Linn SH, Ronquillo Y, Birdsong OC, et al. Initial Single-Site Surgical Experience with SMILE: A Comparison of Results to FDA SMILE, and the Earliest and Latest Generation of LASIK. Ophthalmol Ther 2018:347–60. 17. Qian Y, Chen X, Naidu RK, Zhou X. Comparison of efficacy and visual outcomes after SMILE and FS-LASIK for the correction of high myopia with the sum of myopia and astigmatism from -10.00 to -14.00 dioptres. Acta Ophthalmol. 2020 Mar;98(2):e161-e172. 18. Yin, Y., Lu, Y., Xiang, A. et al. Comparison of the optical quality after SMILE and FS-LASIK for high myopia by OQAS and iTrace analyzer: a one-year retrospective study. BMC Ophthalmol 21, 292 (2021). 19. Cao, K., Zhang, J., Wang, J. et al. Implantable collamer lens versus small incision lenticule extraction for high myopia correction: A systematic review and meta-analysis. BMC Ophthalmol 21, 450 (2021). 20. Hamed AM, Heikal MA, Soliman TT, Daifalla A, Said-Ahmed KE. SMILE intraoperative complications: incidence and management. Int J Ophthalmol. 2019 Feb 18;12(2):280-283. 21. Wang X, Zhou X. Update on Treating High Myopia With Implantable Collamer Lenses. Asia Pac J Ophthalmol (Phila). 2016 Nov/ Dec;5(6):445-449. Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 72 22. Montés-Micó R, Ruiz-Mesa R, Rodríguez-Prats JL, Tañá-Rivero P. Posterior-chamber phakic implantable collamer lenses with a central port: a review. Acta Ophthalmol. 2021 May;99(3):e288-e301. 23. Lackner B., Pieh S., Schimidinger G. Long-term results of implantation of phakic posterior chamber intraocular lenses. J Cataract Refract Surg. 2004;30:2269–2276. 24. Alsmman, Alahmady & Abdellah, Marwa & Abdelatif, I. & Ismail, A.. (2018). CLEAR LENS EXTRACTION VERSUS PHAKIC IOL IMPLANTATION: A PROSPECTIVE STUDY OF TWO PROCEDURES IN PATIENTS WITH HIGH MYOPIA. Egyptian Journal of Clinical Ophthalmology. 1. 25-35 Dr. Neha Kapur, DNB, MNAMS, FSCEH Consultant Cornea and Refractive Service, Dr Shroff’s Charity Eye Hospital. Corresponding Author: Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 73 SMILE (Small Incision Lenticule Extraction) Newer Developments Krishna Prasad Kudlu, MS, Aparna Nayak N Prasad, MS, DNB, FICO Prasad Netralaya Super Speciality Eye Hospital, Udupi, Karnataka. Introduction SMILE is a variant of refractive lenticule extraction technology and is becoming popular as a flapless and minimally invasive form of laser vision correction (LVC) for the treatment of myopia and myopic astigmatism. Background SMILE was reintroduced as an alternative to LASIK called Femto-second Lenticule Extraction (FLEx) intended for patients with high myopia. After improvements in scanning modes and energy parameters, improved visual recovery time was noted, with outcomes similar to LASIK. Following the implementation of FLEx which was a flap based procedure, SMILE was developed with a 2-3 mm incision, allowed extraction of the corneal lenticule without the need of flap. SMILE is said to have similar effects as LASIK with possible benefits such as quicker recovery of post-op dry eye, reinnervation of corneal nerves and said to be more biomechanically stable. The commencement of SMILE began in September 2011 and is established in various countries like Europe, China and India. FDA approval for SMILE for was obtained in 2016 for spherical correction in myopia and in 2018 for compound myopic astigmatic correction. SMILE is considered more cost effective to LASIK because it requires one laser platform as compared to two in LASIK. Machine and Laser Settings The VisuMax Femto-second Laser System (Carl Zeiss, Meditech AG) delivers focused patterns of femtosecond pulses with a wavelength of 1,043 nm with a frequency of 500 kHz to create a refractive intra-stromal lenticule at a pre-decided depth and position. This machine consists of a laser arm, computer unit, vacuum system, patient supporting system, microscope and a foot switch. Diffuse, slit, and infrared illumination are integrated in this machine. The patient interface is a single-use disposable concave contact lens with attached tubing that provides an interface between the cornea and the machine and is referred as treatment pack. It is available in small, medium, and large sizes (S, M, and L, respectively) based on the white-to-white diameter. Three treatment modes are available. • The standard mode: Preset default laser settings programmed by the manufacturers. • Fast mode: Altered only by the application specialists and are customized according to the region. • Expert mode: Modifiable laser settings, which may be optimized by the surgeon before each case as per the surgeon preference and patient response. The laser settings may be modified and changed to set the track distance, spot distance, pulse energy and energy offset. Spot spacing: The distance between two adjacent laser spots and ranges from 2.0-4.5 µm. Track spacing: The distance between two laser spots in adjacent tracks and ranges from 2.0-4.5 µm. Pulse energy: The size of the cavitation bubbles, which are produced during femto-second laser cuts. (Range 100–260 nJ) (Recommended 100-160 nJ). Energy offset: Equivalent to 5 nJ of pulse energy (range 20-52 nJ) (Recommended 20-32 nJ). Indications Workup is similar to flap based refractive procedures. • Myopia -0.5D to -10D • Astigmatism -0.50 to -5.00D Contraindications They are similar to other refractive procedures. Absolute Relative Pre existing corneal ectasia Age< 21 Unstable refractive error Mild/treated ocular/tear film abnormalities Exposure keratopathy Epithelial basement membrane dystrophies Ocular surface/tear film abnormalities: Allergy, severe dry eye, Blepharitis Systemic immunodeficiency Pregnancy/breast feeding Controlled diabetes Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 74 Advantages • Soft and safe suction • Cone is more physiological: curved applanating surface • No changing stations, saves time • Excellent optics of microscope/slit illumination • Less post operative complications, no flap related issues • Early Recovery • Noiseless, Odourless unlike excimer • Biomechanically stable • Less induction of spherical aberration • Better Ocular surface stability Surgical Technique In the Refractive OT, the following parameters are checked: cap thickness, cap diameter, cap sidecut angle, refractive error correction, lenticule diameter (optical zone), lenticule sidecut angle, and the minimum lenticule thickness (so that the lower plane can be easily differentiated from the upper plane). 1. Docking: The patient’s cornea is docked to the applanating contact lens of the femto-second laser. A tear film meniscus forms and the patient is asked to fix at a green blinking light. The centration of SMILE is patient controlled and is fixed on the visual axis. Infra-red light can be used to confirm patient centration. The suction is activated once it applanates 70-80%. Instruction is given to hold still, not to search for the fixating target when it disappears. During suction, the lower IOP is mainly attributed to the corneal suction and curved contact lens present in the VisuMax femto-second laser system. Figure 1: Visumax 500 platform. Figure 2: Lenticule cut. Figure 3: Side cut. 2. Femto-Second Laser Application: The laser first creates the lower lenticule cut in a spiral-in pattern, (Figure-2) followed by a 360° side cut (Figure-3), followed by creation of the upper cap cut in a spiral-out pattern (Figure-4) followed by a 1–4 mm incision cut (Figure-5) (usually superior) that connects the cap interface to the corneal surface. Suction time is approximately 25–35s (depending on the mode) and is independent of refractive error to be treated. Absolute Relative One eyed Past Ocular Herpes Uncontrolled glaucoma, Uveitis History Of Keloid Autoimmune disorders Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 75 Figure 5: Incision. Figure 7: Entry. Figure 8: Anterior plane dissection. Figure 6: Yellow arrow-Outer ring-cap cut White arrow-Inner ring-Lenticule cut Figure 4: Cap cut. 3. Lenticule Dissection: Following femtosecond laser application, a uniform bubble layer is observed in the corneal stroma. Two rings are visible corresponding to the diameter of cap and lenticule and these rings serve as landmark to identify lenticule edge and aid in further dissection (Figure-6). The incision is carefully opened (Figure-7) and the upper and lower planes of the lenticule are identified. The upper plane is first separated, the movement of the instrument should be in a windshield wiper like fashion with the fulcrum at the incision (Figure-8). The lower plane is then dissected in a similar fashion, equally on both the sides, if not the lenticule tends to fold over itself and extraction can become difficult. (Figure-9) Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 76 4. Lenticule Extraction: Once both planes are separated, the lenticule is mobile and is grasped with a pair of micro-forceps (Figure-10) and carefully extracted or can be directly removed from within the pocket using a dissector. One can perform a technique using the forceps similar to capsulorhexis to release any adhesion and to extract the lenticule in-toto. At the end of the procedure, the lenticule is examined for its integrity. (Figure-11) The stromal pocket is washed with saline and the cap is ironed with merocoele sponge to avoid any microdistortions due to interface mismatch. (Figure-12) Figure 10: Lenticule extraction. Figure 12: Ironing the cap. Figure 11: Lenticule integrity. Learning Curve SMILE has a relatively steep learning curve compared to LASIK. It may be more challenging in the initial learning phase. Common Complications • Suction Loss • Black spots • Opaque bubble layer • Cap/side cut tear • Lenticule tear • Retained lenticule • Epithelial defect Recent Advances The applications of SMILE are continuously evolving. The introduction of Visumax 800 in September 2021 has taken SMILE to the next level. It has one of the most striking advancements that is faster performance, reduced surgical time. It also allows for quick cyclotorsion alignment though digital rotation, useful for astigmatism correction. Another valuable addition is computerized centration more useful in hyperopic corrections. Figure 9: Posterior plane dissection. Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 77 It’s not FDA Approved and research is ongoing to evaluate the outcomes in this new platform. Collagen cross-linking has been combined with SMILE (SMILE Xtra) to prevent ectasia in highrisk cases with thin corneas and a higher refractive error. The refractive lenticule obtained from SMILE is undergoing research and is being evaluated in various tissue additive procedures for stromal expansion. Conclusion SMILE is increasingly being preferred over conventional laser procedures for the treatment of myopia and myopic astigmatism and now even hyperopia owing to its precision, better biomechanical stability and healthy ocular surface. Selection of right patient for SMILE is very crucial to achieve optimal visual outcomes and patient satisfaction. References 1. Reinstein, D.Z., Archer, T.J. & Gobbe, M. Small incision lenticule extraction (SMILE) history, fundamentals of a new refractive surgery technique and clinical outcomes. Eye and Vis 1, 3 (2014). https://doi. org/10.1186/s40662-014-0003-1. 2. Titiyal JS, Kaur M, Shaikh F, Gagrani M, Brar AS, Rathi A. Small incision lenticule extraction (SMILE) techniques: patient selection and perspectives. Clin Ophthalmol. 2018 Sep 5;12:1685-1699. doi: 10.2147/OPTH.S157172. PMID: 30233132; PMCID: PMC6134409. Dr. Krishna Prasad Kudlu, MS Medical Director, Prasad Netralaya Super Specialty Eye Hospital, Udupi/Mangalore/Sullia/Thirthalli. Corresponding Author: 3. Ganesh, Sri; Brar, Sheetal; Arra, Raghavender Reddy. Refractive lenticule extraction small incision lenticule extraction: A new refractive surgery paradigm. Indian Journal of Ophthalmology 66(1):p 10-19, January 2018. Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 78 Liquid Cornea: Fact or Fiction? Abha Gour, DOMS, Anil Tiwari, PHD, Virender S. Sangwan, MS Department of Cornea, Anterior Segment and Uveitis, Dr. Shroff’s Charity Eye Hospital, New Delhi, India. The fields of tissue engineering and regenerative medicine has evolved manifold over the last two decades, with significant progress in designing of biomaterials and bioprinting technology which can regenerate the cornea. Many of these have been successfully tried in animal models and are now in various stages of their clinical trials. Anatomically, the cornea is a relatively simple tissue comprising of an upper superficial layer of epithelial cells a middle stromal layer comprising over 90% of the stromal volume and an innermost layer of endothelial cells which help in maintaining the corneal clarity. The stromal layer is comprised of multilayered collagen with an interspersed extracellular matrix. In India, corneal blindness is the second most important cause of blindness in patients over 50 years of age[1], most conditions being treatable with a corneal transplant which could be full thickness or partial based on the pathology. With the availability constraints of corneal tissue and its chances of allograft rejection, these bioengineered derivatives hold a very promising future. Corneal Regeneration: Where Are We? Corneal epithelial regeneration using stem cells has now been widely used with very successful outcomes of simple limbal epithelial transplant[2] for in vitro epithelial cell recovery. Similarly, endothelial regeneration[3] based on donor cell suspension has shown promising results in the animal trial and the human trial for corneal decompensation is now underway. Stromal addition for keratoconus[4] has been widely studied in human trials in the last decade with multiple modalities like stromal volume replacement in the form of stromal and bowmans membrane keratoplasty and stromal regeneration in the form of a) decellularized donor corneal stromal laminas b) Autologous adipose-derived adult stem cells (ADASCs) and c) recombinant crosslinked collagen. With the requirement of very high-quality donor cornea for patients of keratoconus, and the chances of rejection and failure in the long run these regeneration modalities are a very exciting option. Collagen For Stromal Regeneration Collagen is present in various forms in the animal kingdom as seen in (figure-1) out of these the porcine collagen is very similar in composition and biochemical properties to the human collagen. This needs to be decellularized to prevent chances of xenogenic rejection and prion related infectivity in the recipient. With the advent of human recombinant collagen other sources of collagen have very limited utility in sealing of small perforations, or management of anterior stromal scars. Figure 1: Different sources of collagen. Monthly Meeting

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 79 Human Recombinant Collagen Lenticule is a triple helical collagen which contains the same amino acid sequences and a similar extent of proline hydroxylation as the naturally occurring human collagens. This is produced in yeast by recombination of the basic cell derivatives and then crosslinked to make it a robust scaffold to withstand the intraocular pressure and shaped into a lenticule which can be then sutured to the host cornea. This provides an excellent alternative for stromal regeneration with the advantage of minimal risk of infections and chances of rejection. This bioengineered scaffold has been successfully used in patients of advanced keratoconus by Fagerholm et al[5], with minimal complications. Though, the recombinant technology is presently patented by a select few and is expensive it has very promising prospects. Specialized Cell Populated Collagen Lenticule Conditions where in the lenticule is unable to perform the required function, specialized extracellular matrix derived cells may be added to provide the necessary outcome. As in case of anterior stromal scars post injury or infections, where in an anterior stromal keratoplasty may be needed, Basu et al[6] have demonstrated good outcomes in an animal model with lenticules mixed with human corneal stromal stem cells taken from the donor cornea. This provides for the regeneration of the damaged cells and the replacement of the scar tissue with optically clear lenticule. Though this has very encouraging outcomes, the dependency on the donor corneal tissue remains a major deterrent. Tissue Adhesive Gel For smaller perforations needing a cyanoacrylate glue application or a corneal patch graft, a similar adhesive biomaterial Figure 2: Schematic diagram showing the application of the liquid cornea. GelCORE[7] (gel for corneal regeneration) has been used. This is a gel biopolymer which after being placed can be photopolymerized to make it firm enough to provide strength and have a gap filling property. Histological studies in the animal model have demonstrated that this acellular porcine derived collagen shows inflammatory cell infiltration and gradually is replaced by host collagen. 3D Bioprinting This technology offers the advantage of spatially designing a desired lenticule with customized components and of a preconceived shape and size. The components could vary from the keratocytes derived from the donor tissue, human adipose tissue derived stem cells (ADASCs), human plasma and thrombin.[8] These lenticules are still in the early phases of research and the human clinical trials are awaited.Liquid Cornea A combination of the human recombinant collagen and the mesenchymal stem cells is also being evaluated in animal models in its hydrogel form. This helps to replace stromal tissue post scarring due to injury and infections. The advantages of the gel form being a) it fills in the stromal defect and any irregularities in host stromal bed b) also adapts to and maintains the contour of the cornea c) it allows for other additives like stem cells and cross linkers to be added in the composition for the desired effect and d) also integrates with the host by allowing epithelization over its surface. This works by promoting tissue regeneration and hence restoring healthy tissue. This can be applied to the surface of the stroma after surgically dissecting out the diseased tissue (figure-2). Animal studies in mini pigs have shown very encouraging outcomes.[9] Monthly Meeting

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 80 Future Perspectives These different forms of bioengineered human collagen lenticules offer the advantage of being used in combination with each other and with some customization as per the indication of the disease. Multiple groups worldwide are presently working with animal models to find a best suited option for the human trials, the goal being a bioengineered cornea which could be used for indications needing a full thickness keratoplasty. References 1. Malhotra S, Prasad M, Vashist P, Kalaivani M, Gupta SK. Prevalence of blindness in India: A systematic review and meta-analysis. Natl Med J India. 2019 Nov-Dec;32(6):325-333. doi: 10.4103/0970- 258X.303612. PMID: 33380624. 2. Singh A, Sangwan VS. Mini-Review: Regenerating the Corneal Epithelium with Simple Limbal Epithelial Transplantation. Front Med (Lausanne). 2021 May 28;8:673330. doi: 10.3389/fmed.2021.673330. PMID: 34124103; PMCID: PMC8195332. 3. Kinoshita S, Koizumi N, Ueno M, Okumura N, Imai K, Tanaka H, Yamamoto Y, Nakamura T, Inatomi T, Bush J, et al. Injection of cultured cells with a ROCK inhibitor for bullous keratopathy. N Engl J Med. 2018 Mar 15;378(11):995–1003. 4. Lagalli N. Corneal Stromal Regeneration: Current Status and Future Therapeutic Potential. Curr Eye Res. 2020 Mar;45(3):278-290. doi: 10.1080/02713683.2019.1663874. Epub 2019 Sep 20. PMID: 31537127. 5. Fagerholm P, Lagali NS, Ong JA, Merrett K, Jackson WB, Polarek JW, Suuronen EJ, Liu Y, Brunette I, Griffith M. Stable corneal regeneration four years after implantation of a cell-free recombinant human collagen scaffold. Biomaterials. 2014;35 (8):2420–27. 6. Basu S, Hertsenberg AJ, Funderburgh ML, Burrow MK, Mann MM, Du Y, Du Y, Lathrop KL, Syed-Picard FN, Adams SM, et al. Human limbal biopsy-derived stromal stem cells prevent corneal scarring. Sci Transl Med. 2014;6 (266):266ra172. doi:10.1126/scitranslmed.3009644. 7. Sani ES, Kheirkhah A, Rana D, Sun Z, Foulsham W, Sheikhi A, Khademhosseini A, Dana R, Annabi N. Sutureless repair of corneal injuries using naturally derived bioadhesive hydrogels. Sci Adv. 2019;5(3):eaav1281. doi:10.1126/sciadv.aav1281. 8. Sorkio A, Koch L, Koivusalo L, Deiwick A, Miettinen S, Chichkov B, Skottman H. Human stem cell based corneal tissue mimicking structures using laser-assisted 3D bioprinting and functional bioinks. Biomaterials. 2018;171:57–71. doi:10.1016/j. biomaterials.2018.04.034. 9. McTiernan CD, Simpson FC, Haagdorens M, Samarawickrama C, Hunter D, Buznyk O, Fagerholm P, Ljunggren MK, Lewis P, Pintelon I, Olsen D, Edin E, Groleau M, Allan BD, Griffith M. LiQD Cornea: Pro-regeneration collagen mimetics as patches and alternatives to corneal transplantation. Sci Adv. 2020 Jun 17;6(25):eaba2187. Dr. Virender S. Sangwan, MS Department of Cornea, Anterior Segment and Uveitis, Dr. Shroff’s Charity Eye Hospital, New Delhi, India. Corresponding Author: Monthly Meeting

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 81 Intrastromal Copper Wire Ipsita Barman, MBBS, Sohini Mandal, MD, FAICO Cornea, Cataract and Refractive services, Dept. of Ophthalmology, Dr.R P Centre for Ophthalmic Sciences, AIIMS, New Delhi. A male in his 30s presented with history of trauma to the right eye with a broken metallic wire at his workplace two days back. On presentation, visual acuity was 20/80 and 20/20 in right and left eye respectively with normal intraocular pressure. Slit lamp examination revealed a deep stromal metallic wire piece in the visual axis measuring 3mm in length with a selfsealing corneal flap in the right eye. There was no evidence of metallic deposits in the surrounding cornea. (Figure 1A and 1B) The Descemet’s membrane endothelium complex was intact. No other abnormality was detected. A diagnosis of intrastromal metallic foreign body was made. Anterior segment optical coherence tomography (Visante AS-OCT; Carl Zeiss Meditec Inc, Dublin, CA, USA) was performed which delineated the intrastromal location of the foreign body at a depth of 492µm. (Figure-1D) Surgical removal of the foreign body was performed with 26G needle under local anesthesia after lifting the corneal flap using Sinskey hook. The stromal bed was irrigated with saline to dislodge any residual metallic debris. The metallic wire was golden brown in colour and was sent for chemical analysis. After surgery, topical prednisolone acetate 1% four times a day, antibiotics and lubricants were initiated for 2 weeks. On postoperative day 1 the patient had gained vision of 20/40 in right eye. Slit lamp examination revealed mild stromal edema and scar at the site of foreign body. (Figure-1C) Chemical analysis was done by dissolving the metallic foreign body in concentrated nitric acid and analysed using mass spectrometry. The major constituent detected was copper with traces of minor elements. Figure 1: A & B: Slit lamp examination revealed a deep stromal metallic wire piece in the visual axis measuring 3mm in length with a self-sealing corneal flap in the right eye. C: Postoperative day 1 slit lamp examination revealed mild stromal edema with scarring at the site of foreign body. D: Anterior segment optical coherence tomography revealed the intrastromal location of the foreign body at a depth of 492µm. Dr. Sohini Mandal, MD, FAICO Senior Resident in Cornea, Cataract and Refractive Services, Dr Rajendra Prasad Centre for Ophthalmic Science, AIIMS New Delhi. Corresponding Author: Photoessay

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 82 Graft Insertion Devices in DMEK Akshaya Balaji, MD, Sarath S, MD, Prafulla K Maharana, MD Cornea, Cataract and Refractive Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi. Abstract: Descemet membrane endothelial keratoplasty is currently the most advanced and selective technique of endothelial replacement as it involves transplantation of only endothelium and Descemet membrane without involving stroma unlike in Descemet stripping endothelial keratoplasty giving better visual outcomes and faster recovery with lesser rejection rates. Technical challenges associated with this procedure along with specific criteria for donor tissue makes it less popular than Descemet stripping endothelial keratoplasty among the corneal transplant surgeons.[1] The donor graft insertion is an important step as it can lead to endothelial damage due to manipulation and a wide range of devices have been designed to minimise this endothelial cell loss.[1-4] In this article, we discuss about the various DMEK graft insertion devices that are available and used by surgeons worldwide. Introduction In the last 15 years, introduction of endothelial keratoplasty has revolutionized the field of corneal transplantation.[7] Descemet membrane endothelial keratoplasty introduced in 2006 by Melles is a procedure of transplanting Descemet membrane and endothelium with superior visual outcomes and lower graft rejection rates when compared to Descemet stripping endothelial keratoplasty. It is the only endothelial keratoplasty that enables exact anatomic replacement of the diseased Descemet membrane and endothelium complex.[6] Lack of suitable donor corneas and technical challenges have been significant impediments to this procedure. DMEK Graft DMEK graft is 15 µm thin[4] which makes it fragile and prone to damage during preparation and insertion into the host. One of the key steps in DMEK surgery is a controlled delivery of the prepared fragile DMEK scroll into the anterior chamber which will minimize the endothelial cell loss during manipulation. There are two passages in inserting graft-during aspiration into the cartridge and insertion into the anterior chamber during which there can occur contact friction.[4] DMEK Graft Insertion Devices There are various methods of graft insertion such as bimanual technique, contact lens assisted technique and endo-illuminator assisted insertion techniques. Various DMEK injectors are available commercially. An ideal injector is supposed to have the following features: A closed system that is capable of preventing backflow thereby maintaining the anterior chamber. Material that doesn’t damage the endothelium No requirement for viscoelastic Easy loading requiring minimal handling Tapered tip to seal the incision The major difference between the injectors rest in their materialglass or plastic and diameter of their openings. Glass is less toxic to the endothelium as compared to plastic which might adhere to the endothelium.[5] Diameter of these injectors are important because during aspiration of graft into the cartridge larger opening is required to make it atraumatic and smaller opening during insertion into the anterior chamber so that smaller incisions will be required. A) Glass injectors: Pasteur pipette, Geuder glass cannula, DMEK Jones tube, Straiko modified Jones tube and DORC injector (Netherland) B) Plastic injectors: Viscoject IOL injector, STAAR microinjector, Alcon B cartridge, AMO emerald one series injector S.No Name of the Injector Material Used Special Features 1. Pasteur pipette Glass One of the earliest injectors introduced. 2. DMEK Jones tube Glass Glass injector connected to a 3ml syringe for controlled injection and central dilation to control fluidics 3. Straiko modified Jones tube Glass 15mm glass tube modified by widening the mid portion of the tube to allow a fluid reservoir where the aspirated donor tissue can slow down and be captured reducing the risk of aspiration into the attached syringe. The tip has also been modified with tapering and bevelling. The coupling tubing attaches the proximal end of the glass tube to a standard 3-mL syringe filled with BSS.[6] It can be injected through a 2.4mm incision. Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 83 S.No Name of the Injector Material Used Special Features 4. Geuder glass cannula Glass Double port injector with wide entry for aspiration and small port for injection into anterior chamber. Estimated to cause less endothelial cell loss compared to DORC or jones tube.[4] 5. DORC injector Glass Double port injector with wide entry for aspiration and small port for injection into anterior chamber. Requires 1.4mm incision opening.[5] 6. Alcon B cartridge Plastic Simple and inexpensive injector which can be used in 2.8mm incision but drawback is that it cannot create a water-tight closed system.[5] 7. Modified AMO Emerald one series injector Plastic Cartridge attached to a 1ml Luer lock syringe and 14F gauge nasogastric tubing- requires 3.75mm incision 8. Viscoject Injector Plastic Graft is loaded like an IOL and injected through a 2.4mm incision. Easy to use and inexpensive.[4] 9. STAAR Microinjector Plastic Graft is loaded like an IOL and injected through 3mm incision. Requires use of viscoelastic Figure 1: Pasteur pipette Figure 3: Alcon B IOL cartridge Figure 2: DORC DMEK injector Figure 4: Jones tube Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 84 Figure 7: STAAR Microinjector Figure 9: Viscoinjector Figure 5: Gueder glass cannula Figure 6: Straiko modified Jones tube Figure 8: Modified AMO Emerald IOL injector Conclusion With advent of newer technologies and advancement in the field of keratoplasty, there is a paradigm shift from full thickness to endothelial keratoplasty over the few years. Refinement in various steps and wide range of devices designed for DMEK have definitely improved the outcomes both anatomically and functionally. More innovative designs of these devices are essential to overcome the limiting factors and improve the outcome of this procedure. References 1. Droutsas K, Lazaridis A, Kymionis GD, Chatzistefanou K, Moschos MM, Koutsandrea C, Sekundo W. Comparison of endothelial cell loss and complications following DMEK with the use of three different graft injectors. Eye (Lond). 2018 Jan;32(1):19-25. doi: 10.1038/ eye.2017.237. Epub 2017 Nov 17. PMID: 29148524; PMCID: PMC5770720. 2. Price FW Jr, Price MO. Evolution of endothelial keratoplasty. Cornea. Corneal Surgeries

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 85 2013 Nov;32 Suppl 1:S28-32. doi: 10.1097/ICO.0b013e3182a0a307. PMID: 24104929. 3. Shah, Kevin J., Michael D. Straiko and Mark A. Greiner. “Endothelial Keratoplasty Chapter 131 Surgical Technique for DMEK.” (2016). 4. Shen E, Fox A, Johnson B, Farid M. Comparing the effect of three Descemet membrane endothelial keratoplasty injectors on endothelial damage of grafts. Indian J Ophthalmol. 2020 Jun;68(6):1040- 1043. doi: 10.4103/ijo.IJO_1280_19. PMID: 32461426; PMCID: PMC7508103. 5. Shen E, Fox A, Johnson B, Farid M. Comparing the effect of three Descemet membrane endothelial keratoplasty injectors on endothelial damage of grafts. Indian J Ophthalmol. 2020 Jun;68(6):1040- 1043. doi: 10.4103/ijo.IJO_1280_19. PMID: 32461426; PMCID: PMC7508103. 6. Terry MA, Straiko MD, Veldman PB, Talajic JC, VanZyl C, Sales CS, Mayko ZM. Standardized DMEK Technique: Reducing Complications Using Prestripped Tissue, Novel Glass Injector, and Sulfur Hexafluoride (SF6) Gas. Cornea. 2015 Aug;34(8):845-52. doi: 10.1097/ ICO.0000000000000479. PMID: 26075461. 7. Tran KD, Dye PK, Odell K, Galloway J, Stoeger CG, Straiko MD, Terry MA. Evaluation and Quality Assessment of Prestripped, Preloaded Descemet Membrane Endothelial Keratoplasty Grafts. Cornea. 2017 Apr;36(4):484-490. doi: 10.1097/ICO.0000000000001150. PMID: 28129302. 8. Ong HS, Ang M, Mehta J. Evolution of therapies for the corneal endothelium: past, present and future approaches. Br J Ophthalmol. 2021 Apr;105(4):454-467. doi: 10.1136/bjophthalmol-2020-316149. Epub 2020 Jul 24. PMID: 32709756; PMCID: PMC8005807. Dr. Akshaya Balaji, MD Senior Resident in Cornea, Cataract and Refractive services, Dr Rajendra Prasad Centre for Ophthalmic Science, AIIMS New Delhi. Corresponding Author: Corneal Surgeries

DOS Times - Volume 28, Number 5, September-October 2022 www.dosonline.org/dos-times 86 Unilateral Pathological Keratinization: A Skinful Eye Rajwinder[1], MBBS, MD, Akriti Sehgal[2], MBBS 1. Professor, Adesh Institute of Medical Sciences and Research, Bathinda, Punjab. 2. Resident Ophthalmology, Adesh Institute of Medical Sciences and Research, Bathinda, Punjab. Introduction In the human eye when there is pathological transition of a normal nonkeratinized, stratified epithelium into a non-secretory, keratinized epithelium is termed as squamous metaplasia. It is accompanied by the loss of goblet cells, an increase in cellular stratification, enlargement of superficial cells, and keratinization. Severe cases of ocular surface disease are often characterized by diseased conjunctival epithelium covering the cornea and conjunctiva that resembles the keratinized epidermis of skin.[1-2] Case A 44 years old male presented with decreased vision in the left eye with total keratinization of ocular surface, severe dryness that resembles the keratinized epidermis of skin. (Figure-1) Cornea was totally epithelized with no light perception. Right eye was normal. Past history was insignificant. Patient had cataract in the right eye, he underwent phacoemulsification with intraocular implantation. The damage to limbal stem cells and their niche microenvironment leads to limbal stem cell deficiency (LSCD). LSCD is characterized by a loss or deficiency of stem cells which are vital for repopulation of corneal epithelium.[3] Limbus plays an important role in preventing vascularization of cornea, thus with loss of integrity, conjunctival cells migrate to the cornea resulting in conjunctivalization. During the chronic cicatricial phase, most patient progressed through theses stages which includes symblepharon, dry eyes, persistent epithelial defects, conjunctivalization and pathological keratinization.[1] Eventually due to complete ocular surface keratinization in an eye devoid of aqueous tears leads to blindness.[4] Clinical Importance: Early recognition is the key to prevent permanent blindness. Such limbal cell deficiencies are one of the Figure 1: Complete keratinization of the ocular surface that resembles the keratinized epidermis of skin. Abstract: Purpose: The normal ocular surface is a result of corneal, limbal, and conjunctival epithelial cells, which maintain its integrity. Limbal epithelial cells may be damaged by chemical bums, Stevens Johnson syndrome and ocular cicatricial pemphigoid leading to irreversible blindness. Case: A young male presented with unilateral complete keratinisation of ocular surface which resembles skin in the palpebral area. Importance: However, the severe pathological keratinization of nonkeratinized corneal and conjunctival epithelium is a serious and potentially blinding problem that is difficult to manage. Early identification may result in better outcome. Key words: Limbal stem cell deficiency, keratinization, ocular surface greatest challenges to the cornea specialist. Early limbal stem cell transplantation is indicated in such cases. References 1. Kinoshita, S., Nakamura, T., Nishida, K. (2002). Pathological Keratinization of Ocular Surface Epithelium. In: Sullivan, D.A., Stern, M.E., Tsubota, K., Dartt, D.A., Sullivan, R.M., Bromberg, B.B. (eds) Lacrimal Gland, Tear Film, and Dry Eye Syndromes 3. Advances in Experimental Medicine and Biology, vol 506. Springer, Boston, MA. 2. S.C.G. Tseng. Staging of conjunctival squamous metaplasia by impression cytology. Ophthalmology. 92: 728 (1985) 3. Ahmad S, Osei-Bempong C, Dana R, Jurkunas U. The culture and transplantation of human limbal stem cells. Journal of cellular physiology 2010;225(1):15-9 . Inflammation and Cornea

www.dosonline.org/dos-times DOS Times - Volume 28, Number 5, September-October 2022 87 4. Dua HS, Azuara-Blanco A. Limbal stem cells of the corneal epithelium. Survey of ophthalmology 2000;44(5):415-25. Dr. Rajwinder, MBBS, MD Professor, Adesh Institute of Medical Sciences and Research, Bathinda, Punjab. Corresponding Author: Inflammation and Cornea

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