Effects of Topical Insulin on Corneal Epithelium Healing After Corneal Crosslinking in Patients With Keratoconus

The cornea plays a fundamental role in vision, being a complex tissue essential for ocular health. In ophthalmological practice, there are situations such as corneal crosslinking, where damage to the corneal epithelium occurs. Crosslinking is a surgical procedure aimed at strengthening collagen bonds in the corneal stroma to prevent the progression of keratoconus, through the application of topical riboflavin followed by ultraviolet (UV-A) radiation. To enhance the effectiveness of riboflavin and UV-A radiation, the corneal epithelium needs to be removed, which can cause postoperative pain and discomfort, as well as increase the risk of complications such as infections, scarring, corneal opacities, perforations, and recurrent epithelial erosions. Several growth factors play a role in epithelial healing, and the discovery of insulin in the tear film and the presence of insulin and Insulin-Like Growth Factor (IGF-1) receptors in the cornea has raised the hypothesis that insulin may modulate the cornea's wound healing response. Since then, topical insulin has been used for various ocular pathologies, including dry eye disease, persistent epithelial defects, and neurotrophic ulcers. Based on this knowledge, studies have been developed, and promising results regarding the use of insulin in corneal healing have been reported, providing a scientific foundation for the realization of this project. The objective of this study is to evaluate the effect of insulin eye drops at a concentration of 50 IU/ml on epithelial healing in non-diabetic patients undergoing epithelial debridement for corneal crosslinking. To this end, a randomized, double-masked clinical trial will be conducted with two groups, one being the control group, in which researchers will compare the epithelial healing rate in mm²/h between the insulin group and the placebo group, as the primary outcome. Patients diagnosed with keratoconus and with an indication for the crosslinking procedure, will be invited to participate. As a result of the study, it is expected to assess and quantify the impact of topical insulin on epithelial defect closure in patients undergoing crosslinking, compared to placebo. Topical insulin may contribute to early epithelial defect closure, control of inflammation, and prevention of complications that could significantly impact visual quality.