Toxic Effect of Mitomycin C in the Rabbit Ciliary Epithelium

Kim, Sahng Yeon; Park, Jung Je; Lee, Joo Hwa

Abstract

Mitomycin C(MMC) is one of the alkylating agents, which is commonly used adjunctively to inhibit the over-growth of the fibroblasts in high-risk filtering surgery. However, it increases the incidence of the complications including persistent postoperative hypotony. The hypotony may be caused by the toxic effect of MMC on the ciliary epithelium. The morphological changes of the ciliary epithelium were evaluated using transmission electron microscope four and twelve weeks after the application of balanced salt solution(BSS) and MMC on the exposed sclera against the ciliary body in the rabbit eyes. There was no specific change in the ciliary epithelium four and twelve weeks after the application of BSS. Four weeks after the application of 0.2mg/ml of MMC, the mitochondria in the nonpigmented epithelium of the applied region were swollen mildly. The mitochondria of both pigmented and nonpigmented epithelia were swollen moderately in the region applied with 0.5mg/ml of MMC. Twelve weeks after the application of either 0.2 or 0.5mg/ml of MMC, the mitochondria were swollen markedly, the nuclear membranes in the pigmented and nonpigmented epithelia were wrinkled, and the heterochromatins of the nuclei faded in both applied and contralateral ciliary epithelia. These findings indicate that mitomycin C causes degenerative changes in the ciliary epithelium decrease aqueous production.