Efficacy of Topical Insuline in Corneal Epithelial Healing Post PRK

A prospective randomized double-blind controlled trial will be conducted. The informed consent of each patient will be obtained prior to the procedure. All patients will undergo a classic PRK procedure Patients will be instructed to use eye drops blindly in both eyes at a frequency of six times daily: * In one eye: Insulin drops formulated by combining regular human insulin with artificial tears containing polyethylene glycol (PEG 400) 0,25% at a concentration of 1 unit per milliliter. * In the other eye: Placebo drops containing only artificial tears. For the double-blind trial, two identical vials will be provided to each patient: one labeled R (for the right eye) and one labeled L (for the left eye). Using the bloc randomization method, the pharmacy will be the only entity aware of the composition of each vial, ensuring that 50% of patients use insulin drops in the right eye and 50% in the left eye. Every week the drops will be prepared one day prior to the PRK procedure and will be stored in a refrigerator, to be used within one week of their preparation date. Patients will be examined by two ophthalmology residents on days 2 and 4 post-operatively. The size of the epithelial defect in both eyes will be measured using the ImageJ software. Thus, the primary outcome of the study is the ulceration closure rate: the smaller the defect, the faster the epithelial healing is. Additionally, a comparison of subjective symptoms reported by the patient in each eye will be recorded.