Decrease of capsular opacification with adjunctive mitomycin C in combined glaucoma and cataract surgery

Abstract

Objective The authors investigated the incidence of capsular opacification requiring YAG capsulotomy after primary trabeculectomy combined with phacoemulsification and implantation of all polymethylmethacrylate intraocular lenses. Design A prospective randomized study. Participants One hundred seventy-four eyes of 174 nonselected patients with primary open-angle glaucoma (POAG) were randomized to either no adjunctive mitomycin C (MMC) (control group of 93 eyes of 93 patients) or adjunctive subconjunctival MMC (MMC group of 81 eyes of 81 patients) during the primary glaucoma triple procedure (PGTP). Intervention Primary glaucoma triple procedure with and without MMC and YAG laser capsulotomy for posterior capsular opacification (PCO) was performed. Main outcome measures The incidences of YAG capsulotomy for PCO were compared between the control and MMC groups and also between the control group and the MMC subgroups (1 minute, 3 minutes, and 5 minutes of MMC application) using Kaplan-Meier analysis with Mantel-Cox log-rank test. Cox proportional hazard regression analysis also was performed to identify significant factors affecting capsular opacification. Results The control and MMC groups were similar in preoperative characteristics. However, the probability of PCO requiring YAG capsulotomy was significantly lower in the MMC group than in the control group ( P = 0.004). Among the MMC subgroups, MMC application for 3 minutes was most effective and significant when compared with that of the control group ( P = 0.002). Although not as significant as the intraoperative use of MMC ( P = 0.002), old age ( P = 0.026) and presence of diabetes mellitus ( P = 0.035) were also identified as significant beneficial factors for decreasing the incidence of YAG capsulotomy for PCO in Cox proportional hazard regression analysis. Conclusion Intraoperative subconjunctival MMC application during combined glaucoma and cataract surgery has a beneficial effect of inhibiting PCO after combined surgery in patients with POAG. Thus, after intraoperative subconjunctival application of MMC at the concentration of 0.5 mg/ml for 3 minutes, the aqueous MMC level must have been great enough to inhibit the lens epithelial cell proliferation to result in a long-term decrease in PCO.