Impact of Mitomycin-C application time on the scleral Mitomycin-C concentration

The aim of this study was to determine the effect of varying the applicatio n time of Mitomycin-C (MMC) on the scleral concentration of MMC. The sclera e of 14 human donor eyes were used for this study. The episcleral sides of the 4 scleral quadrants of each donor eye were exposed for 0.5, 1, 3 and 5 min to round, 8 mm-diameter sponges soaked with 50 mul of 0.3 mg/ml MMC. Af ter 40-ml irrigation with saline, a central 8-mm diameter scleral disk was punched out, homogenized and analyzed with high performance liquid chromato graphy (HPLC). The scleral MMC concentrations (mug/g) after 0.5, 1, 3 and 5 min application times were 6.40 (+/-3.38), 9.02 (+/-2.40), 12.31 (+/-3.37) , and 13.97 (+/-3.83). The differences of scleral MMC concentration in pair ed t-tests were statistically significant comparing 0.5 with I and 1 with 5 min application. However the effect was relatively small within the range of usual application times (1 to 5 min), and 64% of the MMC was delivered t o the sclera within the first min.