Topical insulin treatment efficacy in rat corneal epithelial defect healing model and comparison of efficacy with topical hyaluronate treatment

ABSTRACT Topical Insulin Treatment Efficacy in Rat Corneal Epithelial Defect Healing Model and Comparison of Efficacy with Topical Hyaluronate Treatment Corneal epithelial defects are a commonly encountered issue in ophthalmology practice. Our study aims to examine the effects of topical insulin on the healing of corneal epithelial defects on experimental corneal epithelial defect model in rats and comparing them with artificial tears and control groups. In the study, 28 adult male Sprague Dawley rats were randomly divided into 4 groups. The control group consisted of rats with no epithelial defect. Group A comprised rats with untreated epithelial defects. Group B included rats with epithelial defects treated with topical 0.15% sodium hyaluronate. Group C consisted of rats with epithelial defects treated with topical insulin. After providing topical anesthesia to the rats in the epithelial defect groups under sedation, a 2 mm diameter epithelial defect was created at the central cornea. Biomicroscopic examinations were performed on all mice at the 4th hour, 12th hour, 1st day, 2nd day, and 3rd day. The size of the epithelial defect was photographed at each examination after fluorescein staining, and the percentage of defect closure was calculated. On the 10th day, after excising the corneal tissues under anesthesia, rats were sacrificed by cervical dislocation, and histopathological examination was conducted. When comparing the rates of corneal epithelial defect closure biomicroscopically, the topical insulin and sodium hyaluronate treatment groups showed faster closure compared to the untreated healing group. However, there was no statistically significant difference in the rate of epithelial defect closure between the topical insulin and sodium hyaluronate groups. Histopathologically, when the healing effects of the tested groups were compared, it was observed that at the fine structural level, the topical insulin group had a faster surface epithelial remodeling process. The second group following this renewal process was the topical sodium hyaluronate group. The slowest renewal in surface epithelium was observed in the untreated epithelial defect group. In conclusion, although no biomicroscopic difference was observed in corneal epithelial healing with topical insulin treatment compared to sodium hyaluronate, it has been demonstrated to be more effective histopathologically. Keywords: Corneal Epitelial Healing, Insulin, Sodium Hyaluronate