INDIVIDUALIZED TOPOGRAPHY-GUIDED CROSSLINKING FOR KERATOCONUS – COMPARISON OF EPI-ON IN HIGH OXYGEN TO EPI-OFF IN ROOM AIR PROTOCOLS.

To compare the efficacy, safety and healing phase of two different Customized Remodeled Vision (CuRV) crosslinking protocols for keratoconus.

Department of Clinical Sciences/Ophthalmology, Umeå University, Umeå, Sweden.

This ongoing study so far includes 27 patients at 12 month follow up with bilateral progressive keratoconus treated with bilateral CuRV; one eye with a high-oxygen epi-on protocol, the other eye with an epi-off protocol in room air, which was randomized and masked to the participant. Uncorrected (UDVA) and corrected visual acuities (CDVA), low-contrast visual acuities (LCVA) at 10% and 2.5%, refractive spherical equivalents (SE), keratometry readings (Kmax), endothelial cell count (ECC) and adverse events were analyzed pre- and post-treatment. The discomfort symptoms during the healing phase for each eye was registered during the first week post treatment.

UDVA improved at 12 months (-0.25 ±0.29 logMAR for epi-on; -0.18 ± 0.17 logMAR for epi-off, (p<0.01), as did the CDVA (-0.11 ± 0.13, -0.11 ± 0.12, respectively, p <0.01), the Kmax (-1.71 ± 2.16, - 1.30 ± 2.15 D, respectively, p <0.01) and 10% LCVA (-0.24 ± 0.36 and -0.15 ± 0.14, respectively, p<0.01). LCVA 2.5 % improved more in epi-on (-0.43 ± 0.93, -0.26 ± 0.66, respectively, p <0.05).The epi-on eyes had less discomfort during the first week post-treatment. A slight reduction in ECC was noted in epi-off (-175 ± 212 cells/mm2, p < 0.01). [AF1] No adverse events occurred.

So far, our results indicate that the novel high-oxygen epi-on treatment protocol may be a promising alternative to epi-off CuRV. Our upcoming 24-months results will show if this impression can be confirmed.