Tensioactive-mediated Transepithelial Corneal Cross-linking – First Laboratory Report

Abstract

Purpose: The aim of this study was to investigate the possibility of delivering riboflavin into the corneal stroma for cross-linking with the aid of a tensioactive substance (benzalkonium chloride), without removing the epithelium, in order to make corneal cross-linking (CXL) a less invasive technique. Methods: Rabbit corneas were cross-linked in vivo without removal of the epithelium, using riboflavin solution 0.1% to which benzalkonium chloride solution was added. The corneas were then examined by light and electron microscopy for evidence of collagen cross-linking. Control non-treated eyes were compared with treated ones. Results: The treated corneas were stiff and yellow in colour, and on light microscope examination they showed straight compact collagen fibres in comparison with control corneas in approximately 50% of the corneal thickness. Electron microscopy revealed regular arrangement of fibres in the outer 200μm with reduced inter-fibre distances in the treated corneas, but with no noticeable differences between control and treated corneas in the inner 100μm. Conclusion: The addition of benzalkonium chloride to the riboflavin solution facilitated its entry to the corneal stroma through the epithelium, and CXL occurred without epithelium removal.