Trabeculectomy with mitomycin-C: outcomes and risk factors for failure in primary angle closure glaucoma

Abstract

Purpose: There are no reported large series of trabeculectomy with mitomycin-C (MMC) in Western patients with primary angle-closure glaucoma (PACG). Our study evaluates long-term tonometric outcomes of trabeculectomy in PACG. Materials and Methods: This is a retrospective cohort study. The primary outcomes were the Kaplan-Meier success rates on survival analyses using 3 criteria, with or without adjunctive medication: (A) intraocular pressure (IOP) <= 18mm Hg and IOP reduction of 20%; (B) IOP <= 15mm Hg and IOP reduction 25%; and (C) IOP <= 12 mm Hg and IOP reduction 30%. In total, 136 eyes (102 patients) with PACG who underwent trabeculectomy MMC were included. The Cox proportional hazard regression analysis was used to identify risk factors for failure with multivariate analysis (P < 0.05). Results: The qualified success rates (+/- SD) after 1, 3, and 5 years of follow-up for criterion A were 92% (+/- 2.2%), 78% (+/- 3.8%), and 72% (+/- 4.3%); for criterion B, 86% (+/- 3.0%), 65% (+/- 4.4%), and 59% (+/- 4.7%); and for criterion C, 62% (+/- 4.2%), 40% (+/- 4.5%), and 32% (+/- 4.4%). Baseline factors associated with failure were: family history, absence of laser peripheral iridotomy, higher IOP, and presence of a crystalline lens. Conclusions: Trabeculectomy with MMC effectively reduces IOP in PACG. Long-term IOP reduction is achieved for target IOP levels in the mid-teens. Presence of a crystalline lens, lack of iridotomy and higher preoperative IOP were associated with higher risks of failure.