Effect of mitomycin-C on corneal endothelial cell parameters after refractive surface ablation procedures

Abstract Background: The effect of mitomycin-C (MMC) on the reduction of endothelial cell count in the cornea remains controversial. We aimed to evaluate the effect of MMC on corneal endothelial cell parameters after refractive surface ablation procedures, including photorefractive keratectomy (PRK) and laser epithelial keratomileusis (LASEK). Methods: In this interventional, comparative, follow-up study, ۳۴۲ eyes of ۱۷۱ patients were followed up for ۶ months. Patients undergoing PRK or LASEK were included and were divided into two groups: group one (۱۸۸ eyes of ۹۴ patients) with an ablation depth of ? ۶۵ µm and who received intraoperative ۰.۰۲% MMC for ۳۰ s, and group two (۱۵۴ eyes of ۷۷ patients) with an ablation depth of < ۶۵ µm and who received balanced salt solution for ۳۰ s. Changes in endothelial cell density (ECD), central corneal thickness (CCT), coefficient of variation (CV), and hexagonality values were compared between the groups at ۳ and ۶ months after surgery. Results: The mean ± standard deviaiton (SD) age of the patients was ۲۸.۱۱ ± ۶.۵۶ years. The mean ± SD ECD did not change significantly in either group between the baseline and at ۳ and ۶ months postoperatively. The baseline mean ECD was significantly higher in group one than that in group two (P < ۰.۰۰۱) and remained so at ۳ (P = ۰.۰۰۲) and ۶ months (P = ۰.۰۲۲) postoperatively. The baseline hexagonality value was lower in group one (P = ۰.۱۷۳), with a gradual decrease during the postoperative follow-up as compared with that in group two (P = ۰.۰۱۶ and ۰.۰۰۱ at ۳ and ۶ months postoperatively, respectively). Group one had a significantly lower CCT at ۳ and ۶ months postoperatively (both P < ۰.۰۰۱) and a higher mean CV (۳ months: P = ۰.۰۲۸; ۶ months: P = ۰.۳۲۸). Conclusions: A single intraoperative application of MMC for ۳۰ s as prophylaxis for corneal haze development during refractive surface ablation procedures had no significant effect on ECD up to ۶ months postoperatively. Future studies with a contralateral-eye design (to neutralize factors specific to the individual patient), a larger sample size, and longer follow-up are necessary to confirm or disprove our observations.