Results of Ahmed glaucoma valve implantation in primary congenital glaucoma

Letters to the Editor RESULTS OF AHMED GLAUCOMA VALVE IMPLANTATION IN PRIMARY CONGENITAL GLAUCOMA To the Editor: We read with interest the article by Razeghinejad and colleagues1 on the results of Ahmed glaucoma valve implantation in primary congenital glaucoma. The study provides valuable data regarding a rarely encountered but potentially blinding childhood disease, considering the homogeneous population and inclusion of only primary congenital glaucoma. The aim of the study and the methods used for patient recruitment and detailed examination are appropriate. However, several pertinent questions remain unanswered. Although visual outcome was not the primary aim of the study, loss of light perception was considered a major complication, which occurred in 1 eye. It is difficult to have confirmatory qualitative evaluation by subjective methods in younger patients, and we would like to know how light perception was assessed. Chen and colleauges2 reported promising results after Ahmed glaucoma valve implantation and quantitative improvement in Snellen visual acuity.2 Morad and colleagues3 reported effective intraocular pressure control but severe visual loss.3 Therefore reporting of quantitative visual acuity assessment is warranted for the limited number of patients capable of assessment. Success or failure of the treatment in glaucoma is considered over 5 years. Survivor function at the far right of a Kaplan-Meier survival curve must be interpreted

Journal of AAPOS

cautiously, because there are fewer patients remaining in the study group and the survival rates are not as accurate.4 In Razeghinejad and colleagues1 only 50% and 20% of patients are available for analysis at the third and fifth years of follow-up, respectively. Anupam Sahu, MS, DNB Dr. Deepshikha Agrawal, MS Dr. Shailen Patel, MBBS Dr. Sumeet Malhotra, MS, FNB Dr. Samrat Chatterjee, MS MGM Eye Institute, Raipur, Chhattisgarh, India

References 1. Razeghinejad MR, Kaffashan S, Nowroozzadeh MH. Results of Ahmed glaucoma valve implantation in primary congenital glaucoma. J AAPOS 2014;18:590-95. 2. Chen TC, Bhatia LS, Walton DS. Ahmed valve surgery for refractory pediatric glaucoma: a report of 52 eyes. J Pediatr Ophthalmol Strabismus 2005;42:274-83. 3. Morad Y, Donaldson CE, Kim YM, Abdolell M, Levin AV. The Ahmed drainage implant in the treatment of pediatric glaucoma. Am J Ophthalmol 2003;135:821-9. 4. Rich JT, Neely JG, Paniello RC, Voelker CC, Nussenbaum B, Wang EW. A practical guide to understanding Kaplan-Meier curves. Otolayngol Head Neck Surg 2010;143:331-6. http://dx.doi.org/10.1016/j.jaapos.2015.02.015 J AAPOS 2015;-:1-1. Copyright Ó 2015 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00

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