Excimer Laser-Assisted Corneal Epithelial Pattern Ablation f
A Study was conducted to determine corneal cross-linking (CXL) efficacy and chromophore penetration after excimer laser-assisted patterned de-epithelialization.

220 porcine eyes were de-epithelialized ex vivo, either fully or patterned. Consecutively, corneas were impregnated with hypo- or hyperosmolar riboflavin or water-soluble taurine, or kept unimpregnated. 60 corneas were subsequently irradiated, inducing CXL, with paired contralateral eyes serving as controls. Outcome measurements included strip extensiometry to assess CXL efficacy, and spectrophotometry and fluorescence microscopy to determine stromal chromophore penetration.

--All tested chromophores induced significant CXL, ranging from 7.6% to 14.6%, with similar stiffening for all formulations and both de-epithelialization method.

--Light transmittance was significantly lower after full compared with patterned de-epithelialization.

--Stromal chromophore penetration was comparable between fully and patterned de-epithelialized samples and penetration depths.

Conclusively, CXL can be achieved using Excimer laser-assisted patterned de-epithelialization. However, the concentration of stromal chromophore is reduced, which could have safety consequences given the need for adequate UVA attenuation in RF/UVA CXL. WST11/NIR CXL may be safe even with low stromal chromophore concentrations due to the distinct safety profile of near-infrared (NIR).

Source: https://onlinelibrary.wiley.com/doi/10.1111/aos.15021?af=R