Use of topical insulin to normalize corneal epithelial healing in diabetes mellitus. Journal   Archives of ophthalmology. Citation   Arch Ophthalmol. 125(8):1082-8 Publication date   2007 Aug Authors   Zagon IS Klocek MS Sassani JW McLaughlin PJ Investigators   Patricia J. McLaughlin Joseph W. Sassani Ian S. Zagon Grants   United States NEI EY16666 MeSH headings   Diabetes Mellitus, Experimental Epithelium, Corneal Hypoglycemic Agents Insulin Wound Healing Wounds, Nonpenetrating MeSH qualifiers   complications drug effects administration & dosage drug therapy Abstract   OBJECTIVE: To determine whether topical application of insulin normalizes delayed corneal wound healing in rats with diabetes mellitus (DB). METHODS: Diabetes mellitus was induced with streptozocin. A 5-mm corneal abrasion at 9 or 11 weeks was treated topically for 7 days (4 times daily) with 1, 2, or 5 U of insulin or with sterile vehicle (SV). RESULTS: Residual corneal epithelial defects of rats with DB receiving SV (hereafter called DB SV rats or animals) were approximately 35% larger than in healthy animals receiving SV (hereafter called healthy SV rats or animals). Rats with DB receiving topical insulin had wounds ranging from 19% to 60% smaller than DB SV rats, corresponding to wound sizes in healthy SV rats. Topical insulin had no effect on reepithelialization of corneal wounds in healthy SV rats. Insulin did not affect corneal thickness, ocular pressure, or serum glucose level. The corneal sensitivity of DB SV rats was markedly reduced from healthy SV rats, but rats with DB given insulin had corneal sensitivity values comparable to the healthy SV group. DNA synthesis was decreased in DB SV corneal epithelium but was comparable to that in healthy SV rats after they received insulin; apoptosis and necrosis levels were similar in all groups. CONCLUSION: Topical insulin normalizes corneal reepithelialization in diabetic rats. CLINICAL RELEVANCE: Direct application of insulin may serve as an important strategy for treating diabetic keratopathy.