Corneal cross-linking ready for modified, scientifically based approaches

The concept of corneal collagen cross-linking (CXL), relies on the potential to induce morphological changes on the fibrils of the anterior stroma by a photochemical process. The interaction between UVA photons and the riboflavin molecules leads to the release of hyperactive free radicals, with the immediate effect of forming fiber-fiber and fiber-matrix bondings, David Touboul, MD, said in the Commentary column of the April 2014 issue of Ocular Surgery News Europe Edition.

The sustained effect is a substantial cellular remodeling due to the cytotoxicity of these radicals, the intensity of which decreases with depth and time. The effect must be mandatorily confined within the anterior stroma to avoid endothelial damage. A minimum of 400 μm of corneal thickness at the thinnest point is required for safety. This estimations does not consider epithelial hyperplasia, which can be detected only by high-resolution optical coherence tomography.

Experimental evidence has shown the effects of CXL in the corneal stroma. Collagen fibrils appear better organized (entropy gain), more wavy and thicker, Keratocyte density increases after cicaatrization between 6 months and 12 months, indicating a certain degree of cell renewal. Finally, the stiffness of the anterior stroma is increased, as well as its resistances to hydration and enzymatic digestion. Get the whole story