Ahmed glaucoma valve in various etiologies of refractory glaucoma: Surgical outcomes and success factors

PURPOSE

To study the epidemiology and mid-term results of the Ahmed glaucoma valve (AGV) in various etiologies of refractory glaucoma in a Lebanese center, and to assess complications and factors that influence the surgical success rate.

METHODS

In this retrospective epidemiological study, we reviewed 108 eyes with refractory glaucoma that underwent an AGV implantation in a tertiary care center in Lebanon between January 2002 and August 2014. Findings including best-corrected visual acuity (BCVA), intra-ocular pressure (IOP), number of antiglaucoma medications, factors influencing the surgical outcome, success rate and complications were also reviewed.

RESULTS

The mean duration of follow-up was 29.85±21.45 months [range, 3-60 months]. As in other Arab countries and compared to the rest of the world, the rate of neovascular glaucoma (NVG) was particularly high, occurring in 63 eyes (58.3%), and represented the primary cause of refractory glaucoma. Mean IOP was significantly reduced to 17.97±7.35mmHg at the last follow-up visit (P<0.05). Similarly, a significant decrease was noted in the number of antiglaucoma medications (P<0.05). The surgical success rate, defined as a postoperative IOP<21, was significantly higher (62.0%), in older patients, those with baseline BCVA≤2 LogMAR and those with a history of hypertension (P<0.01). Hyphema was the most noted complication.

CONCLUSION

The AGV is a safe and effective procedure for lowering IOP in refractory glaucoma patients, with hyphema being the most frequent complication. Both the presence of hyperstension and initial BCVA≤2 LogMAR seem to increase the success rate of the procedure. NVG remains the most common etiology for implantation, probably due to uncontrolled diabetes in the Middle East and North Africa.