Preoperative corneal metrics offer insight into post-CXL vision gain
Preoperative objective markers—corneal optical density (COD), thinnest corneal thickness (TCT), and anterior (ARC) and posterior (PRC) surface radii—can significantly predict the corrected distance visual acuity (CDVA) 1 year after corneal cross-linking (CXL) in keratoconus patients, according to a study. Including preoperative CDVA in these predictions further enhances their accuracy.
The study monitored CDVA, COD, TCT, ARC, and PRC in 3 groups: keratoconus patients treated with routine CXL (Group 1; n = 77), relatively stable untreated keratoconus patients (Group 2; n = 23), and age/gender-matched controls (Group 3; n = 24). The assessments were carried out over a one-year period.
In Group 1, the median logMAR CDVA showed significant improvement from 0.26 to 0.07 (P < 0.01). Significant changes were observed in COD, TCT, ARC, and PRC in this group, while these parameters remained stable in Groups 2 and 3.
The changes in Group 1 were as follows:
- COD: increased from 21.2 to 31.5 grey scale units
- TCT: reduced from 454 µm to 423 µm
- ARC: increased from 6.49 mm to 6.78 mm
- PRC: slightly reduced from 4.81 mm to 4.74 mm
Significant relationships were identified between postoperative CDVA and preoperative values of COD, TCT, ARC, and PRC. A multilinear regression analysis revealed significant correlations between CDVA at one year and preoperative markers, with an r2 value of 0.533, which increased to 0.637 when including preoperative CDVA.
Reference
Gilevska F, Biscevic A, Bohac M, et al. Could Automated Objective Measurements Acquired at the Preoperative Stage Estimate the Corrected Distance Visual Acuity after Corneal Cross-Linking in Keratoconus? Ophthalmol Ther. 2024;doi: 10.1007/s40123-024-00993-0. Epub ahead of print. PMID: 39110318.
