Hydrogel dressings on neurotrophic keratitis in an experimental animal model

Abstract

AIM: To investigate the therapeutic effects of hydrogel dressings on neurotrophic keratitis in rats. METHODS: Male Wistar rats, aged 42–56d, were randomly divided into control, experimental, and treatment groups, each consisting of five rats. The experimental and treatment groups underwent neurotrophic keratitis modeling in both eyes. After successful modeling, biomedical hydrogels formed with polyvinyl alcohol and polyvinyl pyrrolidone were used in treatment group for 7d. Ocular irritation response and keratitis index scores, Schirmer’s test, tear film break-up time (BUT), sodium fluorescein staining, and hematoxylin and eosin (HE) staining were used to evaluate the effectiveness of the treatment. RESULTS: The neurotrophic keratitis model was successfully established in rats with severe ophthalmic nerve injury, characterized by keratitis, ocular irritation, reduced tear secretion measured by decreased BUT and Schirmer test values, corneal epithelial loss, and disorganized collagen fibers in the stromal layer. Following treatment with hydrogel dressings, significant improvements were observed in keratitis scores and ocular irritation symptoms in model eyes. Although the recovery of tear secretion, as measured by the Schirmer’s test, did not show statistical differences, BUT was significantly prolonged. Fluorescein staining confirmed a reduction in the extent of corneal epithelial loss after treatment. HE staining revealed the restoration of the structural disorder in both the epithelial and stromal layers to a certain extent. CONCLUSION: Hydrogel dressing reduces ocular surface irritation, improves tear film stability, and promotes the repair and restoration of damaged epithelial cells by maintaining a moist and clean environment on the ocular surface in the rat model.