MITOMYCIN-C CONCENTRATION IN HUMAN OCULAR AQUEOUS-HUMOR AFTER TOPICALADMINISTRATION DURING TRABECULECTOMY

The concentration of the antitumor antibiotic mitomycin (CAS 50-07-7, mitomycin C, MMC), used in opthalmic surgery for its antiproliferative effects, was measured in the aqueous humor of 7 glaucoma patients und ergoing trabeculectomy. Sponges soaked with MMC-solution (100 mul of M MC-solution 0.2 mg/ml: 20 mug) were applied intraoperatively on the sc leral flap for 5 min. 100 to 200 mul og aqueous humor were drawn with a needle 10 min. following the end of topical MMC-treatment. Samples w ere assayed for MMC using a reverse-phase HPLC-system with ultraviolet detection (C-18-column, elution: phosphate buffer (0.01 mol/l, pH 6.5 ): methanol, v:v = 70:30, 365 nm). Swabs were extracted in phosphate-b uffer (0.1 mol/l, pH: 7.0) before HPLC-analysis. External calibration was used for MMC quantitation. Quantitation limit was 10 ng/ml. In all aqueous humor samples MMC-concentration was below 10 ng/ml. MMC in th e swabs amounted to 37% of the MMC amount applied. Conclusion: after i ntra-operative topical application, the MMC concentration in the aqueo us humor of patients is very low. The substantial loss of MMC from the swabs used for the topical MMC-treatment suggests 1. rapid systemic a bsorption of MMC and/or 2. a loss through irrigation of the operative field following topical MMC-application.