Purpose. To analyze the modifications of the corneal layers after transepithelial (TE) corneal cross-linking (CXL).
Methods. Twenty eyes of 20 patients with progressive keratoconus were treated with TE-CXL (without epithelium debridement), and their corneas analyzed at different times, up to 18 months, by confocal microscopy using a Nidek Confoscan 4.
Results. The epithelial layer, after an initial disorganization due to the TE technique, returned to a normal state after 2 weeks. Keratocytes and nerve fibers in the stroma decreased in number (approximately 25%), to return to a normal density at about 6 months after the procedure. A demarcation dense line indicative of effective cross-linking could be observed after 6 months at a depth of around 60 μm below the Bowman membrane. The endothelium remained unaffected at all examination times.
Conclusions. The TE-CXL procedure appears to be safe and effective at least up to 18 months. The absence of epithelium debridement (necessary in the classical technique) makes the procedure more comfortable for the patient, and allows the treatment of thinner corneas (between 360 and 400 μm) and problematic patients.