Topical insulin for healing of diabetic epithelial defects?: A retrospective review of corneal debridement during vitreoretinal surgery in Malaysian patients

PURPOSE: To investigate whether topical insulin improves healing rate of corneal epithelial erosions induced during vitreoretinal surgery in diabetics.
METHODS: We retrospectively reviewed case notes and serial post-operative photographs of 15 eyes of 14 patients who had corneal epithelial debridement performed during various vitreoretinal surgeries to improve one surgeon's view over a 10 month period in 2010.
RESULTS: Three groups were identified: DTI, comprising diabetics who received topical insulin 1 unit qds postoperatively (n=5); DCT comprising diabetics treated with conventional post-operative medications only (n=5) and NDCT comprising non diabetic patients on conventional post operative therapy (n=5). Only eyes in which the corneal epithelial defect had been serially photographed at time, t= 0, 12, 24, 36, 48, 60, 72 and 120 hours following commencement of topical medications were included. The size of the defect was calculated using local software. DTI eyes had a significantly smaller defect size at t= 24 (p=0.009), 36 (p=0.009), 48 (p=0.015) and 60 hours (p=0.005) compared to DCT eyes and had no statistical difference from NDCT eyes at all times in the Mann Whitney U analysis (p>0.05). In the diabetic operated bilaterally, the insulin treated eye re-epithelialised by 48 hours whereas fellow eye treated conventionally re-epithelialised in 72 hours.
CONCLUSIONS: Topical insulin or insulin eye drops 1 unit qds may be applied to the corneal surface to normalize the rate of healing of epithelial defects in diabetic patients undergoing epithelial debridement to improve the surgeon's view.