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

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.