Comparative Evaluation Of Corneal Haze And Refractive Outcomes After Corneal Cross-Linking Versus Combined Cross-Linking And Selective Wavefront-Guided Transepithelial Photorefractive Keratectomy Without Mitomycin-C

To compare haze development and refractive outcomes in patients who underwent corneal cross-linking (CXL) alone or combined with selective wavefront-guided transepithelial photorefractive keratectomy (WG transPRK) without mitomycin-C (MMC).

Department of Ophthalmology at the American University of Beirut Medical Center between October 2018 to October 2022.

This was a prospective analysis of 90 eyes with progressive keratoconus. The first group of patients (n=43) underwent CXL only, while the second group underwent CXL combined with ocular or corneal WG transPRK (CXL+PRK) (n=47) on the Schwind Amaris. In both groups, the accelerated CXL protocol was followed and MMC was not used. A proprietary patented machine-learning-based algorithm was used for the objective detection and quantification of stromal haze by evaluating OCT scans of the cornea. Additionally, visual, refractive, tomographic, and aberrometry results for the two groups were measured routinely at baseline and then at 1, 3, 6, and 12 months postoperatively.

Anterior corneal reflectivity 1 month postoperatively was 6.12±1.97 for the CXL group and 5.55±2.15 for the CXL+PRK group (P=0.07). At last follow-up, these values decreased to 4.81±2.01 and 5.37±2.22, respectively (P=0.91). The difference in anterior haze reflectivity at 1 month postoperatively and at last follow-up was not significant between the two groups, P=0.88, and P=0.96, respectively. Corrected distance visual acuity improved 0.5 lines for the CXL group (P=0.1) and 2.6 lines for the CXL+PRK group (P<0.001). Maximum keratometry (Kmax) decreased from 51.2±5.12 to 50.1±4.50 for the CXL group (P=0.004) and from 51.9±5.20 to 48.1±8.07 for the CXL+PRK group (P<0.001). Decrease in higher-order aberrations was greater in the CXL+PRK group.

Combining CXL with WG transPRK without MMC application for the management of progressive keratoconus does not result in increased haze development when compared to CXL alone. This combined approach achieves greater improvements in visual, topographic, and aberrometric parameters.