Efficacy and safety of mitomycin-C in primary trabeculectomy: five-year follow-up

PURPOSE: To examine the 5-year complications and results of primary trabeculectomy with mitomycin-C (MMC). DESIGN: Retrospective, noncomparative interventional case series. PARTICIPANTS: One hundred twenty-three eyes that underwent primary trabeculectomy with MMC between December 1991 and March 1995. METHODS: All patients received standard trabeculectomy performed by one of two surgeons, using a Weck cell-soaked pledget of MMC, 0.25, 0.33, or 0.5 mg/ml, for 0.5 to 5 minutes. Laser suture lysis was performed postoperatively for intraocular pressure control. MAIN OUTCOME MEASURES: The incidence of complications, including hypotony with or without maculopathy, bleb leak or blebitis, pressure control, and medication reduction at yearly intervals. RESULTS: Mean preoperative and year 5 postoperative intraocular pressures (IOP) were 25.79 and 9.91 mmHg (P \textless 0.05, paired t test). Hypotony (IOP \textless 6) occurred in 42.2% of eyes after a mean follow-up of 26.1 months. Hypotony maculopathy occurred in 8.9% of eyes at mean follow-up of 33.7 months. Bleb leak occurred in 14.6% of eyes at a mean follow-up of 27.9 months. Blebitis occurred in 5.7% of eyes at a mean follow-up of 35.4 months, and endophthalmitis occurred in 0.8% of eyes at 15 months; 14.9% of eyes lost 4 lines of visual acuity. The single predictor for the development of late-term hypotony was IOP 1 month after operation (P \textless 0.05). CONCLUSIONS: Primary mitomycin trabeculectomy significantly lowers IOP at 5 years but is associated with a high incidence of delayed hypotony.