Trabeculectomy with Multiple Applications of Mitomycin-C in Monkeys with Experimental Glaucoma

Abstract

To inhibit the wound healing process and to achieve a better intraocular pressure lowering effect, we applied mitomycin-C (MMC) topically in trabeculectomy at different time sequences. In this experiment, a model of glaucoma trabeculectomy combined with light microscopic autoradiography study was used to evaluate the clinical and histological effects and the time course of cellular incorporation of tritiated thymidine. This study utilized twelve eyes (divided into three groups) of six monkeys with experimental glaucoma. Group I received 0.08 ml subconjunctival injection of 0.02 mg/ml MMC 24 to 36 hours prior to trabeculectomy. Group II received intraoperative topical application of 0.27 mg/ml MMC for 4 minutes. Group III received the same treatment as group II, along with pre-operative and repeated post-operative conjunctival applications of 0.4 mg/ml MMC for 10 minutes. Surgical success, IOP < 21 mmHg, lasted for a median of 8 days in group I, 56 days in group II and 75 days in group III. Compared with group I, cellular proliferation was significantly inhibited in group II and mostly inhibited in group III. No significant ocular toxicity or profound hypotony was observed. Histological examination of group III on the 90th day after operation showed patent scleral tunnel and hypocellular loose connective tissue in the conjunctival bleb. These results demonstrated that a series of pre-, intra- and repeated postoperative topical applications of mitomycin-C had a prolonged effect in inhibiting wound healing after trabeculectomy in monkeys.