Postoperative application of mitomycin for trabeculectomies

Background: Persistent hypotony is a severe complication following trabecul ectomy with intraoperative application of mitomycin. Objective: To reduce this rate of hypotony by using a lower concentration o f mitomycin and applying the mitomycin only topically to the filtering bleb following surgery. Methods: Patients were enrolled on a consecutive basis and prospectively fo llowed up. Standard trabeculectomies were performed and mitomycin applied p ostoperatively on the 3 days following surgery (group 1). For comparison, d ata from previous studies were used for control, eyes with intraoperative m itomycin application (group 2) and no mitomycin application (group 3). Preo perative and postoperative data, complications, and the need for further su rgical procedures were evaluated. Results: The study group (group 1) consisted of 22 cases. The mean follow-u p was 13.4 and 13.5 months for groups 1 and 2, respectively. Average intrao cular pressure values decreased from 33.6 and 31.0 mm Hg (P = .32; t test) to 16.0 and 12.5 mm Hg in the 2 groups (P = .03; t test). The average numbe r of meditations decreased from 2.5 and 2.5 to 0.6 and 0.4 (P = .35; t test ) in groups 1 and 2, respectively, at the last visit. Hypotony lasting for more than 3 months occurred only in eyes with intraoperative mitomycin appl ication (14/22)1 Choroidal detachment (3/22) and hypotony maculopathy (2/22 ) also were only noted in eyes from group 2. In group 3, success rates were much lower. Conclusions: This is the first clinical study, to our knowledge, to evaluat e the efficacy of this new technique of mitomycin application. From the res ults, it appears that the postoperative application of mitomycin following trabeculectomy is associated with a lower risk of severe and long-standing hypotony. This technique may be promising in eyes at low risk for failure.