Mitomycin C may improve the lowering of IOP one year after trabeculectomy in eyes with high risk for fibrosis and in eyes without previous surgery.
Literature through Macrh 2005 was undertaken in the Cochrane systematic review. Randomised trials of intraoperative MMC were compared to placebo in trabeculectomy surgery. 11 trials, involving a total of 698 participants, were included. Mitomycin C appeared to reduce the relative risk of failure of trabeculectomy both in eyes at high risk of failure (relative risk 0.32, 95% confidence interval 0.20 to 0.53) and those undergoing surgery for the first time (relative risk 0.29, 95% confidence interval 0.16 to 0.53). No significant effect on failure was noted in the group undergoing trabeculectomy combined with cataract extraction. Mean IOP was significantly reduced at 12 months in all three participant groups receiving MMC compared to placebo. No significant increase in permanent sight-threatening complications was detected. However, none of the trials were large enough or of sufficient duration to address the long-term risk of bleb infection and endophthalmitis which has been reported in observational studies. Some evidence exists that MMC increases the risk of cataract.