Changes of Higher-Order Aberrations After Different Types of LASIK in Myopia

This prospective comparative interventional study will enroll patients with low and moderate myopia who seek laser vision correction at Sohag Center for LASIK and Corneal Surgeries, Sohag, Egypt. Eyes included will be divided into 3 groups according to the type of refractive surgery used (conventional LASIK, Femto-LASIK and PRK) and each group will be subdivided into 2 groups according to the degree of myopia (low and moderate). All patients will be subjected to routine comprehensive preoperative examinations including manifest uncorrected distant visual acuity (UCDVA), best corrected distant visual acuity (BCDVA), slit-lamp examination, intraocular pressure, and fundus examination. Corneal topography and corneal aberrometry will be performed on all patients using Sirius's Scheimpflug-Placido topography (CSO, Florence, Italy). The CSO topography system analyzes a total of 6144 corneal points of a corneal area within a circular annulus outlined by an inner radius of 0.33 mm and an outer