Corneal De-epithelization Associated With a Therapeutic Photokeratectomy in Patients With Evolutive Keratoconus

Overview

Keratoconus is a symmetrical, bilateral, non-inflammatory, idiopathic corneal pathology, characterized by a progressive corneal thinning. This disease leads to a bombing of the cornea, inducing a strong corneal astigmatism, responsible for a loss of visual acuity sometimes very important, non-correctable by lens of glasses. Collagen Cross-Linking (CXL) and simple corneal de-epithelization are two common surgical technics aiming to slow the progression of this pathology. They consist in rigidifying the corneal structure in order to stabilize its deformation progression. Even though these technics are commonly performed, none of these strategies has proven their efficiency. The effects of CXL can be due to the superficial scarring reaction as well as the effects of corneal remodeling induced by the de-epithelization phase during a CXL procedure, and not due to the covalent links between collagen and fibrils, formed by the biochemical reaction resulting from the UV-A exposition in the presence of Riboflavine De-epithelization may be an equally effective treatment, when compared to CXL, but without long term secondary effects. Its association with a therapeutic photokeratectomy (PKT, surgical technic used to regulate the corneal surface, and eliminate its opacities in order to recuperate the transparency of the cornea) will aim to improve the regularity of the anterior corneal surface, thus allowing a better epithelial attachment (adhesion) and may allow a stromal inflammatory reaction, favorable to the improvement of corneal biomechanics. PKT is a reliable technic; however it has not yet proven its efficiency in the treatment of keratoconus. The purpose of this study is to describe the effects of de-epithelization associated with a therapeutic photokeratectomy in patients with evolutive keratoconus, by showing the proportion of patients who lost the evolutivity of their keratoconus, after 6 months and 1 year, after an intervention of de-epithelization associated with therapeutic photokeratectomy.