The Future of Corneal Cross-linking

Abstract

As corneal cross-linking (CXL) gains momentum worldwide, new advances and uses of CXL continue to emerge. In general, many of these developments are directed toward making the procedure more efficient, safe, and comfortable for the patient. A number of groups are evaluating the safety and efficacy of accelerated CXL treatments, which are accomplished by higher UV fluences or the use of deuterated water, for instance. A variety of transepithelial delivery systems, which enable the diffusion of riboflavin past an intact epithelium, have been described that could potentially avoid the morbidities associated with epithelial debridement. These systems include the use of penetration enhancers, microneedles, intrastromal channels, ultrasound, iontophoresis, and vacuum. Contact lens-assisted CXL has been developed to aid in the safe treatment of thinner corneas. At the same time, some groups have sought to demonstrate how disease states other than keratoconus (KC) and corneal ectasia may benefit from the technology. These diseases include the treatment of infectious keratitis (Photo-activated Chromophore for Keratitis – Corneal Cross-linking (PACK-CXL)) and corneal edema. Finally, significant investment has been made toward the correction of refractive error using CXL, as either an adjunct to laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) (e.g., LASIK extra or LASIK-CXL), or as a means to directly alter the curvature of the cornea (Photorefractive Intrastromal Cross-linking (PiXL)) without the need for incisions or laser-based ablation of the stroma.