Effects of mitomycin-C on tear film function following photorefractive keratectomy for mild-to-moderate myopia

Background: Mitomycin C (MMC) is used to prevent corneal opacity after photorefractive keratectomy (PRK). This study sought to determine the effect of MMC on tear film function after PRK in eyes with mild-to-moderate myopia.Methods: This prospective, contralateral eye comparison was conducted on 30 eyes of 15 patients with low-to-moderate myopia referred to Alzahra Eye Hospital, Zahedan, Iran. The eyes of the control group underwent PRK with a balanced salt solution, while the fellow eyes in the intervention group underwent PRK with 0.02% MMC for 25 s. The tear breakup time test (TBUT) and basic Schirmer test results of eyes in the control and intervention groups were compared at baseline and 1, 3, and 6 months postoperatively. Tear osmolarity was recorded and compared at baseline and 3 months postoperatively. Results: The mean ± standard deviation (SD) age of participants was 27.53 ± 7.04 years. No statistically significant differences were observed in the means ± SDs for tear osmolarity, TBUT, and basic Schirmer test values (all P > 0.05) between MMC-treated eyes and untreated fellow eyes at baseline and during postoperative follow-up. The means ± SDs for tear osmolarity, TBUT, and basic Schirmer test results were comparable in both groups between the baseline and postoperative follow-ups (all P > 0.05). Conclusions: Single application of a standard dose of MMC (0.02%) for 25 s in PRK did not change tear stability, tear production, or variation in tear dynamics up to 6 months postoperatively in eyes with low-to-moderate myopia. Future longitudinal studies with a longer follow-up and a larger sample size are warranted to confirm our findings.