Postoperative application of mitomycin for trabeculectomies.

BACKGROUND Persistent hypotony is a severe complication following trabeculectomy with intraoperative application of mitomycin. OBJECTIVE To reduce this rate of hypotony by using a lower concentration of mitomycin and applying the mitomycin only topically to the filtering bleb following surgery. METHODS Patients were enrolled on a consecutive basis and prospectively followed up. Standard trabeculectomies were performed and mitomycin applied postoperatively on the 3 days following surgery (group 1). For comparison, data from previous studies were used for control eyes with intraoperative mitomycin application (group 2) and no mitomycin application (group 3). Preoperative and postoperative data, complications, and the need for further surgical procedures were evaluated. RESULTS The study group (group 1) consisted of 22 cases. The mean follow-up was 13.4 and 13.5 months for groups 1 and 2, respectively. Average intraocular 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 number of medications 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 application (14/22). 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 evaluate the efficacy of this new technique of mitomycin application. From the results, 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.