The Effects of Mitomycin C on Tear Function After Photorefractive Keratectomy: A Contralateral Comparative Study

PURPOSE: To assess the effects of adjuvant mitomycin C (MMC) on tear function tests after photorefractive keratectomy (PRK) for myopia. METHODS: In this prospective, randomized, double-blind study, one eye of myopic patients undergoing PRK was randomly chosen for PRK and the other eye was treated with PRK plus the application of 0.02% MMC for 20 seconds onto the ablated stroma. All patients had corneal esthesiometry, fluorescein break-up time testing, fluorescein and Rose Bengal staining, and Schirmer testing with anesthesia, and they also completed a questionnaire preoperatively and at 1.5, 3, 6, and 12 months after surgery. RESULTS: Twenty-seven patients with a mean age of 25 +/- 3.27 years were enrolled. There were no statistically significant differences between the PRK and PRK+MMC groups regarding the symptoms and tear function tests preoperatively or at any postoperative follow-up visit. Preoperative and postoperative results in the total sample were also compared; statistically significantly different results were observed in fluorescein break-up time and dry eye symptoms at 1.5 months, which showed improvement thereafter. Corneal sensation was significantly lower at all postoperative follow-up visits compared with preoperative results. CONCLUSIONS: The intraoperative use of MMC during PRK did not induce tear deficiency, and it seems that MMC can be used safely when necessary.