Histatin-5 Improves In Vivo Corneal Wound Healing and Immunohistochemical Neovascular Markers After Acute Alkali Injury

Purpose: Histatin-5 (Hst5), an endogenous antimicrobial peptide, has recently been shown to promote corneal epithelial wound healing and reduce inflammation after injury. This study aimed to investigate whether topical Hst5 treatment can inhibit corneal neovascularization and promote tissue recovery in a murine model of alkali burn injury. Methods: Mice were randomly assigned to two groups: balanced salt solution (BSS) and Hst5-treated (5 mL of 20 µM stock) after alkali injury. Alkali burns were induced on the cornea of each mouse and topically treated three times a day for up to two weeks. Wound closure was analyzed through epithelial wound healing, corneal opacity, and neovascularization. Histologic analysis was also conducted. Results: Topical Hst5 treatment significantly accelerated corneal wound healing, reducing residual epithelial defect area by ∼60% at 18 hours and achieving complete closure by 24 hours, compared with BSS-treated controls. Corneal opacity scores were significantly lower in the Hst5 group from Day 7 with near-clear corneas by Day 14. Neovascularization scores were markedly reduced in Hst5-treated eyes at Day 14, and accompanied by decreased infiltration of CD45⁺ immune cells. Conclusions: Hst5 reduces alkali burn-induced corneal epithelial wound healing time, opacification and neovascularization in murine models. Future research is required before clinical implementation; however, the results suggest a potential therapeutic role for Hst5 for alleviating the adverse effects associated with acute corneal alkali injuries. Translational Relevance: Topical Histatin-5 promotes epithelial regeneration and suppresses inflammation-driven corneal neovascularization following alkali injury, suggesting Hst5 as a novel, biologically-derived treatment to accelerate corneal healing and prevent vision loss after chemical burns.