Three-years outcomes of simultaneous photorefractive surgery and customized corneal cross-linking for keratoconus

Purpose: To report the efficacy of customized cross-linking (CXL) in halting progression of keratoconus when combined with photorefractive procedures.

Methods: Seven eyes from 7 patients with documented progressive keratoconus were treated with customized CXL (customized ultraviolet-A irradiance pattern centered on the maximum posterior elevation with total energy levels ranging from 5.4 up to 10 J/cm² , and an energy fluence of 9 mW/cm²) combined with photorefractive procedures. Four patients underwent simultaneous transepithelial photorefractive keratectomy (T-PRK) plus customized CXL, and three patients underwent simultaneous transepithelial phototherapeutic keratectomy (T-PTK) plus customized CXL. Tomographic parameters (K_max, pachymetry of the thinnest point and maximal elevation of posterior float and regularization index) and best spectacle-corrected visual acuity (BSCVA) were compared preoperatively and 3 years postoperatively.

Results: All eyes showed a decrease in the maximal curvature K_max, and none of eyes showed progression. Six eyes showed a flattening of 3 or more diopters (D). On average, K_max decreased by - 4.8 ± 2.5 D, and the BSCVA improved by 0.04 ± 0.07 logarithm of the minimal angle of resolution. The mean value of regularization index was 8.7 ± 3.8 D. Mild corneal haze occurred in two eyes, and superficial apical scar occurred in one eye. None of the eyes had a vision-threatening complication.

Conclusion: Customized CXL combined with photorefractive procedure (T-PRK/T-PTK) resulted in long lasting flattening effect and strong regularization of keratoconic corneas along with improvement of BSCVA over a 3-year follow-up.