Evaluation of Posterior Corneal Surface in Keratoconus Patients after Corneal Cross-Linking by Pentacam

Abstract

eratoconus is a progressive non-inflammatory, degenerative disease that affects the integrity of the collagen matrix within the corneal stroma. Its hallmark is the formation of a localized cone-shaped ectasia, it is accompanied by thinning of the stroma in the area of the cone. This might cause irregular astigmatism and a steeper corneal curvature . An imbalance between degradative enzymes such as; lysosomal enzymes, cathepsins and matrix metalloproteinase-2 (MMP-2) and their inhibitors; Alpha-1 proteinase inhibitor, alpha-2 macroglobulin and tissue inhibitor of metalloproteinase-1 and 3 is now understood to be the reason behind the development of Keratoconus . Due to the great variability among patients with keratoconus, it is vital to grade this disease in order to provide some general guidance for the clinician regarding the level of progression and the treatment options that can be offered. There are various classifications depending on which principal factors are considered. Traditionally, the most widely used classification is the Amsler-Krumeich (1946) scale. This scale is based primarily on keratometric criteria but also includes other factors, such as refraction and pachymetry . Pentacam is a multipurpose, fast and non-co