Transepithelial corneal collagen crosslinking: Bilateral study

PURPOSE: To evaluate the efficacy of transepithelial collagen crosslinking (CXL) in patients with bilateral progressive keratoconus. SETTING: Outpatient ophthalmic clinic. DESIGN: Cohort study. METHODS: Patients with a history of bilateral progressive keratoconus were recruited. The worst eye was treated with transepithelial CXL, while the fellow eye was left untreated as a control. Transepithelial CXL was performed by applying an enhanced riboflavin solution (riboflavin 0.1%, dextrane T500 with trometamol [Tris-hydroxymethyl aminomethane] and EDTA [ethylenediaminetetraacetic] sodium salt) on the intact corneal epithelium for 30 minutes before irradiation with ultraviolet A (370 nm at 3 mW/cm(2)) for 30 minutes. Follow-up was 18 months in all eyes. RESULTS: The study enrolled 20 patients. Transient hyperemia and mild foreign-body sensation occurred in 8 eyes (40%) after treatment; both resolved after 24 hours. In treated eyes, there were statistically significant improvements in uncorrected and corrected visual acuity and topography-derived keratometry, cone apex power, and higher-order aberrations (P<.05). In untreated control eyes, there was a general trend toward worsening of these parameters. No complications were reported. CONCLUSIONS: Transepithelial CXL treatment appeared to halt keratoconus progression, with a statistically significant improvement in visual and topographic parameters. The treatment was safe and well tolerated. Its noninvasive nature makes it potentially useful in cases in which epithelial debridement is ideally avoided, such as pediatric cases, uncooperative patients, and thin corneas with thicknesses nearing 380 mu m.