Long-term effects on corneal keratocytes of mitomycin C during photorefractive keratectomy: a randomized contralateral eye confocal microscopy study.

PURPOSE To evaluate the long-term side effects of mitomycin C (MMC) assisted photorefractive keratectomy (PRK) on corneal keratocytes of highly myopic eyes. METHODS Twenty-eight patients with bilateral myopia from -7.00 to -14.25 diopters (D) underwent PRK on both eyes, one eye of each patient received topical application of 0.02% MMC for 2 minutes immediately after the PRK procedure. Corneal keratocyte density was quantified by corneal confocal microscopy at baseline and 5 years postoperatively. RESULTS Photorefractive keratectomy reduced keratocyte density in the most anterior stromal layer, without a statistically significant difference between MMC and standard treated eyes. Posterior stromal layers showed no signs of keratocyte loss with either techniques. CONCLUSIONS Phototherapeutic keratectomy with 0.02% topical MMC has no significant side effects on corneal keratocytes compared to standard PRK, as documented by in vivo corneal confocal microscopy.