Comparison of the Outcome of Repeat Trabeculectomy with Adjunctive Mitomycin C and Initial Trabeculectomy

PURPOSE: To compare the efficacy and safety of repeat and initial trabeculectomy with mitomycine C (MMC). METHODS: Eighty seven patients, who had underwent repeat (repeat group) or initial (initial group) trabeculectomy with MMC, were enrolled in this prospective trial. Postoperative outcome measures included the amount of decrease in intraocular pressure (IOP), the number of anti-glaucoma medications, and the complications. The success of trabeculectomy was defined on the basis of three definitions which were: IOP ≤18 mmHg (definition 1), IOP ≤21 mmHg (definition 2), and the amount of decrease in IOP from baseline ≥30% (definition 3). Success was further defined as "complete" when these criteria were obtained without any anti-glaucoma medications and "qualified" with or without medical therapy and no further surgical procedures. RESULTS: Fifty nine eyes underwent initial and 28 eyes underwent repeat trabeculectomy. The mean follow-up period was 19.1 ± 5.9 months. Complete success rates were significantly greater in the initial trabeculectomy group (p = 0.02 for definition 1, p = 0.038 for definition 2, p = 0.003 for definition 3). A higher proportion of eyes in the initial group achieved qualified success relative to the group A eyes, but the differences were not statistically significant (p = 0.33 for definition 1, p = 0.99 for definition 2, p = 0.24 for definition 3). The mean number of antiglaucomatous medications at the last examination was 1.2 ± 1.2 in repeat group and 0.7 ± 1.1 in initial group (p = 0.01). The number of complications during the follow up period did not differ significantly between the two groups (p = 0.65). CONCLUSIONS: Repeat trabeculectomy with MMC has high success and low complication rates in patients with previously failed trabeculectomy in spite of the need of higher number of anti-glaucoma medications.