Long-term Effects of Mitomycin on Filtering Blebs

Abstract

The use of antimetabolites, such as fluorouracil and mitomycin, enhances the success rate of filtering surgery, especially in eyes at high risk for failure, and increases the likelihood of a thin, avascular filtering bleb. In addition, mitomycin may cause long-term inhibition of the fibroblast's ability to proliferate in the conjunctiva and Tenon's capsule. Preoperative and postoperative inflammation frequently contributes to scarring of filtering blebs. The purpose of this study is to evaluate the effect of intraoperative mitomycin use on the survival of filtering blebs after severe inflammation. We retrospectively studied three eyes that had undergone trabeculectomy with intraoperative mitomycin. Two eyes had concomitant intraocular lens implantation. All three eyes had blebs that functioned well postoperatively. These eyes sustained episodes of intense inflammation in the form of herpes zoster ophthalmicus, endophthalmitis, or purulent infection of the bleb postoperatively. Following treatment of the inflammation, no change in the appearance or function of the bleb could be detected. Either the indirect effect of mitomycin in producing a thin, avascular bleb or a long-term effect of mitomycin on the ability of conjunctival and Tenon's capsule fibroblasts to proliferate may have contributed to bleb survival.