Effects of External Irrigation on Mitomycin-C Concentration in Rabbit Aqueous and Vitreous Humor

PURPOSEThese experiments were performed to determine what effect external irrigation with balanced salt has on limiting penetration of mitomycin-C into the aqueous and vitreous. METHODSBilateral 5 min scleral applications of mitomycin-C (0.5 mg/ml) were performed in 21 rabbits using identical 6x4x1 mm cellulose sponges uniformly soaked with 0.2 ml of the mitomycin-C solution. Irrigation of one eye, randomly selected, was then carried out with 10 ml of balanced salt solution over 1 min. High performance liquid chromatography was used to analyse aqueous and vitreous samples obtained from separate animals at 5, 15, 30, and 60 min and at 2,4, and 6 h after sponge removal. RESULTSNonirrigated eyes demonstrated continual rise in aqueous mitomycin-C concentration over 1 h. Irrigated eyes demonstrated lower mitomycin-C concentrations at all times studied and a continual fall in aqueous concentration after 15 min. Vitreous mitomycin-C was detected in both groups only at 5 min. CONCLUSIONSIrrigation with balanced salt substantially reduces intraocular diffusion of mitomycin-C.