Topical insulin for refractory persistent corneal epithelial defects

Purpose: To evaluate insulin eye drops for persistent epithelial defects (PEDs) that are refractory to usual treatment in clinical practice and to analyze how it may improve epithelization. Methods: A prospective non-randomized hospital-based study was performed. Patients with PEDs that were refractory to conventional treatment were treated with insulin eye drops four times a day. Patients' demographics, PED etiology, concomitant treatments, and comorbidities were reviewed. The rate of PED closure and epithelial healing time were considered the primary outcome measures. Results: 21 patients were treated with insulin drops (12 females and 9 males; mean age 72.2 years). Mean PED area before treatment was 17.6 +/- 16.5 mm(2)(median 13.2; range 3.9-70.6). PED comorbidities included seven eyes with infectious keratitis (33%), five eyes with calcium keratopathy (24%), ocular surgery on three eyes (14%), three eyes with lagophthalmos (14%), two eyes with bullous keratopathy (10%), and one patient with herpetic eye disease (5%). The eyes of 17 patients (81%) with refractory PEDs had reepithelized and four patients (19%) had still presented an epithelial defect by the end of the study follow-up period, although it had decreased in size. In patients where PED closure was achieved, mean time until reepithelization was 34.8 +/- 29.9 days (median 23; range 7-114). In the remaining patients, a mean area reduction of 91.5% was achieved for the PEDs. Conclusion: Topical insulin can promote and accelerate corneal reepithelization of refractory PEDs. It also offers many other advantages, including excellent tolerance, availability, and cost-effectiveness.