Evaluation of the effect of corneal collagen cross-linking for keratoconus on the ocular higher-order aberrations

Ahmed Abdel-Karim El-Massry, Amgad Mostafa Dowidar, Tamer Hamdy Massoud, Baher Guirguis Daoud Tadros Department of Ophthalmology, Faculty of Medicine, Alexandria University, Alexandria Governorate, Egypt Background: Corneal collagen cross-linking (CXL) is the only treatment currently available to arrest the progression of keratoconus. The procedure consists of photopolymerization of stromal collagen fibers induced by combined action of a photosensitizing substance (riboflavin or vitamin B2) and ultraviolet-A light.Purpose: To determine changes in the ocular higher-order aberrations (HOAs) after CXL and its correlation with changes in visual acuity.Design: Prospective interventional study.Subjects and methods: This study was conducted on 30 eyes of 16 patients with progressive keratoconus documented between 2012 and 2014. Patients were treated with epithelium-off CXL and followed for a minimum of 6 months. The following ocular HOAs were measured and analyzed using I-Tracey Aberrometer: coma, trefoil, spherical aberration, astigmatism, and total HOAs.Results: There was statistically significant improvement in uncorrected visual acuity and best-corrected visual acuity between the preoperative and 6-month evaluations (P