Effect of Mitomycin C with Different Application Methods on Rabbit Cornea after Excimer Laser Surgery

ABSTRACT

PURPOSE: We evaluated the effect of Mitomycin C (MMC) applied by different methods, on corneal healing after excimer laser phototherapeutic keratectomy (PTK) in rabbits. METHODS: PTK was performed on 34 eyes of 17 New Zealand white rabbits. The control group underwent PTK alone, while the experimental groups underwent PTK with intraoperative application of either annular or discoid filter paper soaked with 0.02% MMC for 2 minutes. At postoperative 4, 12, and 24 weeks, the degree of corneal haziness was determined using a slit lamp biomicroscope, and the proliferation of keratocytes was observed histologically. RESULTS: At 4 weeks, the degree of corneal haziness was significantly lower in both MMC-treated groups than in the PTK-alone group (P<0.001). The two MMC-treated groups also showed decreased corneal haziness at 12 and 24 weeks, although the change was not statistically significant. In addition, the MMC-treated groups showed less proliferation of keratocytes at 4 and 12 weeks. At 24 weeks, the group that received annular application of MMC showed a significant decrease of keratocytes compared with the control group(p=0.026), while the group with discoid application showed no significant difference. CONCLUSIONS: In this study, we found that the annular application of MMC after PTK not only shows similar effect on wound healing but also reduces the side effects of MMC by minimizing the application surface.