A Prospective Randomized Trial of Ahmed Glaucoma Drainage Device Implantation with or without Ologen Collagen Matrix

Abstract

The purpose of this study is to evaluate the effectiveness of Ologen collagen matrix (OCM; Aeon Astron Corporation) in the prevention of the postoperative hypertensive phase and on long-term intraocular pressure (IOP) control after Ahmed glaucoma valve (AGV; New World Medical) implantation. This is a prospective, randomized, controlled study of 26 patients treated at a tertiary care center, with 13 eyes assigned to each treatment arm. Consecutive patients with refractory glaucoma requiring AGV implantation were enrolled. Refractory glaucoma was defined as IOP >21 mmHg on maximum tolerated glaucoma medications or progressive visual field and optic nerve head changes despite maximal tolerated medical therapy. In Ologen eyes, a round 12 × 1-mm OCM segment was placed flush over the AGV-FP7 plate immediately before conjunctival closure. Control eyes received conventional AGV surgery without OCM implantation. The primary outcomes were postoperative IOP and requirement of pressure-lowering medications. On the basis of these measures, the rates of complete and qualified success over the course of follow-up were calculated. Complete success was defined as IOP ≤21 mmHg without antihypertensive medications. Qualified success was defined as IOP ≤21 mmHg with or without medications. Frequency of hypertensive phase was also determined. Patients receiving Ologen-augmented AGV surgery exhibited significantly lower IOPs compared with control subjects at the 1-, 2-, and 3-month time points (P < 0.04). Maximum mean IOP postoperatively was 25.2 ± 7.4 for control eyes and 16.8 ± 8.9 for Ologen eyes, peaking at month 2 for both groups and stabilizing by month 6. No differences in average number of pressure-lowering medications were detected between groups. There were no statistically significant differences in complete or qualified success rates at 6 and 12 months. The frequency of hypertensive phase was 61.5% in control eyes and 38.5% in OCM-implanted eyes. Ologen collagen matrix-augmented AGV surgery may provide better IOP control in the intermediate postoperative period and blunt the hypertensive phase compared with AGV implantation alone.