Baerveldt glaucoma implant versus ahmed glaucoma implant in a one-year follow up, comparative study

Abstract

Aim: To compare clinical outcomes between Ahmed glaucoma implant (AGV-S2 and FP7 models) and Baerveldt–350 glaucoma implant (BGI). Design: Prospective randomized study. Methods and subjects: Eighty-one participants with glaucoma after ocular surgery or secondary glaucoma with persistent and uncontrolled IOP > 21 mmHg were randomized for placement of BGI or AGV models using a standardized surgical technique. The primary outcome was failure, which was defined as IOP >16 mmHg with glaucoma medication, on 2 consecutive study visits. Secondary outcomes were IOP, medication use, visual acuity, complications, and interventions. Results: At one-year follow up, the mean IOP was 14.76±2.5 mmHg in BGI group and 16.57±3.35 mmHg in AGV group (P=0.015). The mean number of glaucoma medications in use was 1.6±0.81 in the BGI group and 3.91±0. 0.28 in the AGV group (P <0.001). There was 1.81 mmHg difference in the mean IOP between participants in both groups with 0.85 SD difference. At 12 months, the failure rate was 11/56 (19.67%) in AGV group and 3/25 (12%) in BGI group (P=0.352). The VA was stable in 77% in the BGI group (P=0.93) versus 80% of patients in AGV group (P=0.88). No significant change was observed in logMAR Snellen VA between both groups (P=0.254). None of the patients lost light perception. Conclusion: Both the Ahmed valve implant and the Baerveldt implant are effective in reducing preoperative IOP and glaucoma medications in patients with refractory glaucoma. This trial cannot give clear clinical proof for valve superiority over the other. The Baerveldt-350 implant can be a good choice for refractory glaucoma cases. Capsular scarring around the plate is considered as the main factor for surgical failure and resistant IOP. Trial registration: The trial was registered with the Research Ethical Committee, Ain Shams University, FWA 000017585 FMASU 21/2017, and registered at Clinical Trial. gov: NCT04215575.