Enhanced Trans-Epithelial Accelerated Crosslinking Protocols: The Way Out of Future CXL

Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions: theoretical basis

“…These procedures are based on the use of ocular penetration enhancers: substances that increase the trans-corneal passage of riboflavin, such as ethyl alcohol [34] , mixtures of benzalkonium chloride [35][36] , trometamol, EDTA [28,32] and local anesthetics [35] ; the role of these substances was to cause partial or complete disruption of the epithelial barrier by damaging the desmosomal junctions, to allow riboflavin to spread into the corneal stroma [37] . We went from a mechanical EPI-OFF to a chemical one, with two immediate consequences: less effective removal with lower performance than the standard treatment and an increase in unwanted effects [17,34,38] . For these reasons, the EPI-ON treatments did not initially meet the hoped-for success, except for iontophoresis, in which electrodes are applied near the eyeball and a weak current is applied to the surface of the cornea which facilitates, during the phase of imbibition, the passage of a solution of positively charged riboflavin through the epithelium [39][40] .…”