Filtering Operation with Adjunctive Mitomycin-C in Rabbit: Comparative Study by Subconjunctival Injection and Soaking of Mitomycin-C

ABSTRACT

We examined the differences of the glaucoma filtering blebs according to the application methods of mitomycin C (subconjunctival injection and soaking). We performed filtering surgery from the anterior chamber to the subconjunctival space with the silicone tube, in both eyes of 12 grey rabbits. In one eye, subconjunctival injection of the mitomycin-C 0.05ml after filtering surgery (concentration 0.004, 0.008, 0.012, 0.016%) was performed and on the other eye, Weck-Cel sponge soaked with the 0.04% mitomycin-C was applied for 3 minutes and the wound was washed with copious amount of balanced salt solution before the closure of wound. We examined the size, shape, vascular distribution of the filtering blebs and status of the anterior chamber after filtering surgery. We obtained the tissues of the filtering bleb at 7days, 14days and 21days after surgery and microscopic examinations were performed. In subconjunctival injection with the 0.004% of mitomycin-C, bleb size and its duration was small and short than those eyes with the soaking. In eyes with subconjunctival injection with the 0.008% of mitomycin-C, bleb size and its duration showed similiar blebs to soaking cases and anterior chamber was shallow in one eye. In case of 0.012% subconjunctival injection, bleb size and duration were greater than those with soaking and slightly shallow anterior chamber was shown in all cases. In cases of subconjunctival injection with 0.016% mitomycin-C, shallow anterior chamber and hypotony were common. In histological examination, there was similiar findings of fibroblast activity between 0.008% subconjunctival injection and 0.004% soaking cases. Therefore we conclude that the concentration of mitomycin-c in subconjunctival injection for glaucoma filtering surgery should not be higher than 0.008%.