Topical Insulin-Utility and Results in Refractory Neurotrophic Keratopathy in Stages 2 and 3

Purpose: The purpose of this study was to evaluate the clinical outcome of patients with refractory neurotrophic keratopathy (NK) in stages 2 and 3 treated with topical insulin. Methods: Retrospective analysis of eyes with NK in stages 2 and 3 refractory to standard medical and/or surgical treatment which were treated with topical insulin (1 unit per mL). This treatment was applied 4 times per day and was continued until the persistent epithelial defect (PED) or ulcer resolved. The primary outcome of the study was the complete reepithelialization of the PED or persistent ulcer. "Best-corrected visual acuity" pretreatment and posttreatment, "days until complete reepithelialization" data, and anterior segment photographs were obtained. Outcome measures were compared before and after treatment in both groups using paired and independent samples t tests. Results: Twenty-one eyes were included in this study, and 90% achieved complete reepithelialization of the PED and/or persistent ulcer within 7 to 45 days of follow-up. The mean number of days until complete reepithelialization was significantly lower in NK stage 2 (18 +/- 9 days) when compared with NK stage 3 (29 +/- 11 days) (P = 0.025). The best-corrected visual acuity improved significantly in both NK stage 2 (P < 0.001) and NK stage 3 (P = 0.004). No side effects were reported during the follow-up. Conclusions: Our results suggest that topical insulin drops may be an effective therapeutic in refractory NK. This therapy may prove extremely useful because of its low cost and high accessibility.