Outcomes of Trabeculectomy With Transconjunctival Application Versus Subconjunctival Application of Mitomycin C.

Purpose: To compare outcomes and complication rates of trabeculectomy with either transconjunctival mitomycin C (MMC) or subconjunctival MMC application.

Methods: Retrospective cohort study-35 eyes in subconjunctival group and 29 eyes in transconjunctival group. All surgeries were performed by 1 surgeon (E.A.) at 1 center with an average follow-up duration of 40 to 51 months.

Results: The mean percentage intraocular pressure reduction at final follow-up was with 44.4±25.3% reduction in the subconjunctival group compared with 48.0±24.6% reduction in the transconjunctival group, with no statistical significant difference between the 2 groups (P=0.57). Both groups also showed a >40% reduction in intraocular pressure in approximately 67% of eyes. There were no cases of endophthalmitis. There was 1 reported case of choroidal hemorrhage following subconjunctival application of MMC. There were similar low rates of postoperative bleb leakage and requirement for postoperative application of 5-fluorouracil. There was a greater incidence of hyphema in the subconjunctival group (5 vs. 1) as well as choroidal effusions (8 vs. 4). One patient underwent revision of trabeculectomy and this was in the subconjunctival group.

Conclusion: Transconjunctival application of MMC offers a safe and effective method of performing trabeculectomy with adjunctive MMC with lower rates of complication than subconjunctival application.