Alterations in endothelial cell density after photorefractive keratectomy with adjuvant mitomycin.

PURPOSE: To elucidate the distinct role of the intraoperative use of mitomycin C (MMC) on endothelial cell density after photorefractive keratectomy (PRK) in human eyes.

DESIGN: Prospective, double-masked, randomized clinical trial.

METHODS: One eye of 15 patients was treated with PRK with intraoperative use of topical 0.02% MMC (15 seconds), whereas the fellow eye was treated with Epipolis laser in situ keratomileusis (Epi-LASIK) in random order. Corneal confocal microscopy was performed in all eyes preoperatively and at one, three, six, and 12 months after the surgery. Moreover, three endothelial images were acquired in each of 15 preoperative-normal eyes to evaluate the repeatability of measuring endothelial cell density. Repeated measures analysis of variance was used to compare the temporal variations of endothelial cell density between the two techniques and the changes of endothelial cell density over time.

RESULTS: The coefficient of repeatability of endothelial cell count was 148 cells/mm(2). Preoperative endothelial cell density was not significantly different between the two groups (P = .82). Moreover, the effect of the treatment on the temporal variation of endothelial cell density was insignificant (P = .83), whereas the differences between the preoperative and the postoperative endothelial cell densities reached statistical significance (P <or= .05). Nonetheless, inclusion of the repeatability of the instrument on the analysis diminished these significant differences (P > .05).

CONCLUSIONS: The prophylactic intraoperative application of MMC (up to 15 seconds) after PRK does not seem to affect the endothelial cell density.