Outcomes of Small Size Ahmed Glaucoma Valve Implantation in Asian Chronic Angle-Closure Glaucoma

For chronic angle-closure glaucoma (ACG), Ahmed glaucoma valve (AGV) is a useful drainage device for intraocular pressure (IOP) control but there are few reports discussing the outcomes of small size AGV in adult patients. This retrospective study involved 43 Asian adult patients (43 eyes) with chronic ACG. All patients had undergone small size AGV insertion and were divided into anterior chamber (AC) group and posterior chamber (PC) group. In the AC group, tube was inserted through sclerectomy gap into the anterior chamber. In the PC group, tube was inserted into posterior chamber through a needling tract. Outcome measures were intraocular pressure (IOP), visual acuity, number of antiglaucoma medications, survival curve and incidence of complications. In total, 43 eyes of 43 patients, 24 in the AC group and 19 in the PC group, were reviewed. The mean follow-up period was 28.5 months (95% confidence interval: 25.5-31.4). Mean IOP had significantly decreased following AGV insertion. The Kaplan-Meier survival analysis demonstrated a probability of success at 24 months of 67.4% for qualified success and 39.5% for complete success. There were no significant differences between the AC and PC groups in terms of the mean IOP, cumulative probability of success, visual acuity change or antiglaucoma medication change, except IOP at 1-day and 1-month mean IOP. The most common complications noted was hyphema in the PC group. For adult chronic ACG patients, small size AGV insertion could be effective at lowering IOP. Besides, tube insertion into AC with sclerectomy may prevent the hypertensive phase in the early postoperative period.