Customized Topography-Guided Crosslinking In Keratoconus - Comparison Of Epi-On High/Oxygen To Epi-Off/Room Air Protocols

To compare the efficacy, safety and healing of two icustomized crosslinking (CXL) protocols for keratoconus.

University hospital eye clinic

This single-masked, intra-individually comparing study includes 30 patients with bilateral progressive keratoconus treated with bilateral CXL and followed through 24 months. One eye was treated with acustomized highoxygen epi-on protocol, the other eye with a customized epi-off protocol in room air, which was randomized. Uncorrected (UDVA) and corrected visual acuities (CDVA), low- contrast visual acuities, refractive spherical equivalents (SE), endothelial cell count (ECC) and adverse events were analyzed before treatment and through 24-month follow-up. The discomfort symptoms during the first week post-treatment was registered for each eye using a visual analogue scale.

These are the final results of our study, showing that outcomes such as UDVA, CDVA, Kmax and LCVA 10% improved at 24 months for both protocols. LCVA 2.5% improved for the epi-on protocol only. The LCVA improvement was generally faster with epi-on, and the epi-on eyes also had significantly less discomfort during the first week post-treatment. ECC was unchanged and no adverse events occurred with either protocol.

Our final 24-months results show that the customized high-oxygen epi-on treatment protocol is a viable alternative to an epi-off protocol, with similar final outcomes but a more rapid and pronounced low contrast visual improvement and significantly less early pain and discomfort.