Efficacy of mitomycin C irrigation after removal of an occluded nasolacrimal stent

PURPOSE: Mitomycin C (MMC) acts as a potent fibroblastic inhibitor, and topical application of MMC is effective in preventing scar formation. The purpose of this study was to evaluate the safety and efficacy of MMC irrigation after removal of an occluded nasolacrimal stent from the lacrimal system. MATERIALS AND METHODS: A total of 57 lacrimal systems after removal of an occluded stent were assigned to one of two groups: 23 lacrimal systems were irrigated with MMC after stent removal (MMC group), and 34 lacrimal systems were not irrigated with MMC after stent removal (non-MMC group). In the MMC group, the lacrimal systems were irrigated with 0.2 mg/mL MMC through the inferior lacrimal punctum for 3 minutes in three different sessions: immediately, 1 week, and 1 month after stent removal. The mean and cumulative patency rates after stent removal were calculated using the Kaplan-Meier method and were compared between the two groups using the log-rank test. RESULTS: Stent removal and MMC irrigation were technically successful in all lacrimal systems. There were no side effects or complications associated with MMC use. The mean patency rate after stent removal was higher in the MMC group than that of the non-MMC group: 10.5 months (95% CI: 7.04, 13.91) versus 4.5 months (95% CI: 2.40, 6.63), respectively. There was a statistically significant difference in the cumulative patency rates after stent removal between the two groups (P = .005, log-rank test). CONCLUSIONS: Mitomycin C irrigation is safe and effective in increasing patency rate of lacrimal systems after removal of an occluded nasolacrimal stent.