Transepithelial CXL appears to halt keratoconus progression, improve vision

This small study in the February issue of the Journal of Cataract & Refractive Surgery evaluated the efficacy of transepithelial collagen crosslinking (CXL) in patients with bilateral progressive keratoconus. The authors found that it is safe and well tolerated and appears to halt keratoconus progression.

They observed a statistically significant improvement in visual and topographic parameters and a stabilization of corneal keratometry in treated eyes. They conclude that transepithelial CXL's noninvasive nature makes it potentially useful in cases in which epithelial debridement is ideally avoided, such as in children, uncooperative patients and patients with thin corneas with thicknesses nearing 380 µm.

Transepithelial CXL involves the use of a specially formulated riboflavin solution, Ricrolin TE (Sooft Italia SpA). It includes two enhancers, trometamol and sodium ethylenediaminetetraacetic acid, that help riboflavin penetrate the corneal stroma through an intact epithelium.

The authors treated with transepithelial CXL the worse eye of 20 patients with previously documented progressive keratoconus. Fellow eyes remained untreated as controls.

Treated eyes experienced statistically significant improvements in uncorrected and corrected visual acuity and topography-derived keratometry, cone apex power and higher-order aberrations (P < 0.05). Untreated control eyes experienced a general trend toward worsening of these parameters.

Transient hyperemia and mild foreign-body sensation occurred in eight eyes (40 percent) after treatment but resolved after 24 hours. No complications were reported.

The authors say that transepithelial CXL is simple to perform and has some advantages. Because of the preservation of the epithelial layer, it does not require a sterile environment and can be performed in an office setting, especially given that UV emission reduces any bacterial load on the cornea. The technique does not require an operating microscope because epithelial debridement is not required. Additionally, patients avoid the postop pain and the temporary worsening of vision associated with classic CXL.

The authors conclude that if transepithelial CXL proves to be as efficacious as classic CXL, its noninvasive nature and simplicity would make it the procedure of choice for corneal collagen CXL.