Trabeculectomy With Mitomycin C for Open-Angle Glaucoma in Phakic Eyes vs. Pseudophakic Eyes After Phacoemulsification

Abstract

Purpose: : There have been early studies on the surgical outcomes of trabeculectomy in aphakic or pseudophakic eyes. However, whether recent pseudophakic eyes, that is eyes that have undergone phacoemulsification, are more resistant to trabeculectomy with mitomycin C (MMC) than phakic eyes has not been evaluated yet using direct comparative data between phakic eyes and pseudophakic eyes. The aim of this study is to determine whether previous phacoemulsification adversely affects surgical prognosis of trabeculectomy with MMC for open-angle glaucoma (OAG).

Methods: : This is a retrospective, consecutive, comparative cohort study. At two Japanese hospitals, we reviewed 226 charts of OAG eyes with initial trabeculectomy; 175 phakic eyes (Phakic Group) and 51 pseudophakic eyes that had previously undergone phacoemulsification with superior conjunctival incision (Pseudophakic Group). Primary outcome was the probability of success after trabeculectomy. Surgical failure was defined by an additional glaucoma surgery or three criteria: Criterion A, intraocular pressure (IOP) greater than or equal to 21 mm Hg; Criterion B, IOP greater than or equal to 18 mm Hg; and Criterion C, IOP greater than or equal to 15 mm Hg. Multivariate analysis was performed using the Cox proportional hazards model.

Results: : The mean follow-up period was 37.5 ± 31.6 months. The probability of success for Criteria A, B and C at 1 year (3 years) in the Phakic Group vs the Pseudophakic Group was 97.8% (92.6%) vs 78.6% (65.1%) for Criterion A (P < 0.0001), 92.9% (81.3%) vs 72.8% (63.7%) for Criterion B (P = 0.004), and 73.1% (54.2%) vs 53.1% (38.4%) for Criterion C (P = 0.009). The multivariate model confirmed that pseudophakia independently contributes to surgical failure (Criterion A, relative risk [RR] = 4.59, P = 0.0006; Criterion B, RR = 2.88, P = 0.004; and Criterion C, RR = 2.02, P = 0.009). The Pseudophakic Group required more postoperative laser suturelysis (P = 0.01).

Conclusions: : Previous phacoemulsification is a prognostic factor for surgical failure of trabeculectomy with MMC for OAG.

Keywords: clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: outcomes/complications • wound healing