Transconjunctival penetration of mitomycin C

AIMS: The study was performed to estimate transconjunctival penetration of mitomycin C (MMC) to Tenon′s tissue following application over the intact conjunctiva before routine trabeculectomy. SETTINGS AND DESIGN: Institution-based case series. MATERIALS AND METHODS: In 41 eyes of 41 patients, MMC (0.4 mg/ml for 3 min) was applied over the intact conjunctiva before beginning trabeculectomy. Tenon′s capsule directly beneath the site of application was excised during trabeculectomy and was homogenized, centrifuged and MMC concentrations were analyzed using high-performance liquid chromatography (HPLC). STATISTICAL ANALYSIS USED: Statistical analysis was performed using stata0 8.0 version software (STATA Corporation, Houston, TX, USA). In this study, P -values less than 0.05 were considered as statistically significant. RESULTS: The average weight of the sample of Tenon′s tissue excised was 5.51 ± 4.42 mg (range: 0.9-17.1) and the average estimated MMC concentration found to be present in Tenon′s tissue using HPLC was 18.67 ± 32.36 × 10(−6) moles/kg of the tissue (range: 0.38-197.05 x 10(−6) ). In 36 of the 41 patients (87.80%), the MMC concentration reached above 2 x 10(−6) moles/kg of the tissue concentration required to inhibit human conjunctival fibroblasts. CONCLUSIONS: Mitomycin C does permeate into the subconjunctival tissue after supraconjunctival application for 3 min. Application of MMC over the conjunctiva may be a useful alternative to subconjunctival or subscleral application during routine trabeculectomy and as an adjunct for failing blebs.