Objective: To investigate the effects of mitomycin C on haze after photorefractive keratectomy.
Methods: Forty-five rabbits underwent bilateral 193 nm excimer laser photorefractive keratectomy to correct 8 diopters of myopia. All eyes were allocated randomly to be treated with 0.008% mitomycin C during operation, or 0.1% dexamethasone after operation, or no medical treatment as control. Clinical and histopathologic examinations were made with slit-lamp microscope, specular microscope, light microscope and transmission electron microscope.
Results: At 4, 8 weeks after operation, the corneal haze was significantly less in mitomycin C group than that in the control group or in dexamethasone group, and the corneal haze was significantly less in dexamethasone group than that in the control group. At 1, 4, 8 weeks, the number of keratocyte in the anterior stroma of ablation area was significantly less in mitomycin C group than in the control group or in dexamethasone group. The difference between dexamethasone group and the control group was insignificant. The changes in time of reepithelialization, thickness of epithelium and keratocyte number of anterior stroma in ablation area were statistically insignificant among all groups.
Conclusion: Mitomycin C can reduce corneal haze by inhibiting the proliferation of keratocyte and has no toxicity on cornea. Mitomycin C is more effective than dexamethasone on haze.