Outcomes of Ahmed glaucoma valve surgery performed by glaucoma fellows - A large retrospective study from Eastern India

Purpose: Teaching and training of glaucoma fellows on the technique of Ahmed glaucoma valve (AGV) implantation surgery is very important. The purpose of this study was to describe the clinical outcomes and complications of AGV surgery performed by glaucoma fellows of a tertiary eye center from eastern India. Methods: This was a retrospective study based on electronic medical records. Thirty-five eyes operated with AGV by five glaucoma fellows from January 2016 to November 2020 were included. Best-corrected visual acuity, intraocular pressure (IOP), and number of antiglaucoma medications (AGMs) were the study outcome measures. Results: The mean (+/- standard deviation) age of the patients was 40.5 (+/- 19.7) years. The follow-up period was 24.37 (+/- 13.01) months. Both complete success (IOP <21 mmHg without additional AGM) and qualified success (IOP <21 mmHg with an additional AGM) were achieved in eight eyes each (22.8%). Failure of the surgery was noted in 19 eyes (54.3%) as there was a need for repeat surgery for IOP control in 12 eyes and a persistent IOP spike (IOP >21 mmHg with AGM beyond 3 months) in seven eyes. Despite a high rate of failure of the primary surgery, with the consultants' intervention, there was statistically significant improvement in vision and IOP in all patients (P < 0.01) at the last follow-up. Conclusion: AGV implantation is a challenging surgical skill to be acquired by the glaucoma fellows.