Purpose: To examine the efficacy of trabeculectomy with mitomycin C 0.3 mg/ml using titrated exposure times.
Methods: A retrospective chart review of consecutive patients undergoing trabeculectomy in an academic referral glaucoma clinic was performed. All patients received trabeculectomies performed by one surgeon (M.B.S.). The study included 57 eyes of 57 patients using mitomycin C with exposure times titrated from one to five minutes based on risk factors for trabeculectomy failure. Surgical success was defined as a final intraocular pressure (IOP) of less than 21 mmHg with or without medications or a 25% reduction in IOP if preoperative IOP was 21 mmHg or less. Patients requiring repeat trabeculectomies were considered failures regardless of their final IOP. Patients receiving different mitomycin C exposure times were compared but statistical analysis was not used because these subgroups were not randomized.
Results: An overall surgical success rate of 84.2% was achieved at a mean follow-up of 11.9 months. The surgical success rate and percentage IOP reduction was similar between exposure time subgroups. Hypotonous maculopathy observed in three patients (5.3%). All cases of hypotonous maculopathy was occurred in the lower-risk patients receiving one to three minute exposure times to mitomycin C.
Conclusions: We believe mitomycin C should be used sparingly if at all in patients at lower risk for trabeculectomy failure. This concentration of mitomycin C with four to five minute exposure times appears to be efficacious for patients with multiple risk factors for trabeculectomy failure.