Abstract
Abstract: :
Purpose: To determine the effect of mitomycin C on the cornea following single intraoperatiave application. Methods: Sixty-three pigmented rabbits received mechanical debridement of the central 10 mm corneal epithelium. MMC1 corneas (n = 42) underwent 0.1 mg/ml mitomycin C solution soaking for 2 minutes. MMC2 corneas (n = 42) received 0.2 mg/ml mitomycin C solution soaking for 2 minutes. Control corneas (n = 42) underwent balanced salt solution soaking for 2 minutes. Difference in the central corneal thickness, corneal clariaty, epithelial defect size, among the three groups were examined on days 0, 1, 2, 3, 5, 7 and 14. Corneal endothelial cell density change was studied using trypan blue and alizarin red S staing while endothelial apoptosis was examined using annexin-V/Propidium iodide staining at the same time. Results: There was an increase in corneal thickness and a decrease in corneal clarity after single intraoperative mitomycin C application, which change was more significant in MMC2 than in MMC1 eyes. The endothelium was significantly swollen and became pleomorphic and polymegathic with a concomitant decrease in endothelial cell density in a dose dependent manner. The endothelial apoptosis was more significant in MMC2 than in MMC1 corneas. Conclusions: Single application of mitomycin C on the corneal surface caused a dose dependent apoptosis of the corneal endothelium. The recommended dose of 0.2 mg/ml MMC soaking for 2 minutes was too high for cornea from this rabbit model. Prophylactic use of mitomycin C for PRK in high myopia or cases with thin corneas should be cautious of potential endothelial damage.
Keywords: refractive surgery • refractive surgery: complications • cornea: endothelium