Prevention of exuberant granulation tissue and neovascularization in the rat cornea by naltrexone. Journal   Archives of ophthalmology. Citation   Arch Ophthalmol. 126(4):501-6 Publication date   2008 Apr Authors   Zagon IS Klocek MS Griffith JW Sassani JW Komáromy AM McLaughlin PJ Investigators   James W. Griffith Patricia J. McLaughlin Joseph W. Sassani Ian S. Zagon Grants   United States NEI EY16666 United States NEI K12 EY015398 MeSH headings   Corneal Neovascularization Granulation Tissue Naltrexone Narcotic Antagonists MeSH qualifiers   prevention & control drug effects administration & dosage Abstract   OBJECTIVE: To determine whether topical application of naltrexone prevents exuberant granulation tissue formation with neovascularization in diabetic rat corneas. METHODS: Diabetes was induced with streptozotocin. A 5-mm corneal abrasion at 9 or 11 weeks was treated topically for 7 days (4 times daily) with naltrexone or a sterile vehicle. RESULTS: Within 2 to 5 days after reepithelialization, diabetic rats given the sterile vehicle had a 41% incidence of corneal lesions represented by exuberant granulation tissue with corneal neovascularization extending from the limbus. These lesions exhibited edema, cellular and vascular inflammation, and disruption of stromal lamella by fibrovascular tissue and calcium mineralization, but infection was not detected. No corneal lesions were recorded in the diabetic group treated with naltrexone or the control group given the sterile vehicle. Diabetic rats with corneal lesions given the sterile vehicle reepithelialized more slowly than diabetic rats given the sterile vehicle without such lesions, but no difference in blood glucose levels were noted. CONCLUSIONS: Using a minimally invasive model in diabetic rats, topical naltrexone normalizes corneal wound healing and prevents neovascularization. CLINICAL RELEVANCE: Direct application of naltrexone may serve as an important strategy for facilitating corneal healing and inhibiting corneal neovascularization.