Effect of mitomycin C in pterygium surgery on corneal endothelium

PURPOSE: To evaluate changes in endothelial cell count after pterygium surgery with 5-minute application of mitomycin C (MMC) 0.02%. METHODS: The study participants included 24 consecutive patients (17 men and 7 women) who underwent pterygium surgery with MMC at a major tertiary center between September and October 2005. The bare sclera technique was used in all cases. After excision of the head and neck of the pterygium, a surgical sponge soaked with MMC 0.02% was placed on the exposed sclera for 5 minutes, with the conjunctival layer draped over the sponge. Thereafter, the sclera was irrigated with balanced salt solution, and surgery was completed. Endothelial images were acquired at the center of the cornea with a specular microscope (average of 3 measurements) before surgery and at 1 week, 1 month, and 3 months after surgery. RESULTS: Mean preoperative endothelial cell count was 2254 ± 128 cells/mm. The percentage of postoperative cell loss was 21.25% ± 2.8% at 1 week, 24.26% ± 1.8% at 1 month, and 21.05% ± 3.2% at 3 months. The difference in cell count from the preoperative value was significant at all time points (P < 0.02). There were no adverse drug effects and no serious operative complications. CONCLUSIONS: A 5-minute application of MMC 0.02% to the bare sclera during pterygium surgery has an immediate and significant effect on endothelial cell density, which remains stable for up to 90 days. Furthermore, longer-term studies are needed of different concentrations and durations of the drug and of procedures wherein MMC is applied before excision of the pterygium head.