Trabeculectomy with Mitomycin-C: Outcomes and Risk Factors for Failure in Primary Angle-closure Glaucoma

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) ≤18 mm Hg and IOP reduction of 20%; (B) IOP≤15 mm 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.