Comparison of Visual and Corneal Parameters Before and After Corneal Cross-Linking Therapy in Patients with Keratoconus

Abstract

Background: Keratoconus is a progressive ectatic corneal disorder leading to irregular astigmatism and reduced visual acuity, and corneal collagen cross-linking (CXL) is used to improve biomechanical stability and delay progression. Objective: To compare visual acuity and corneal parameters before and six months after epithelium-on accelerated CXL in patients with keratoconus. Methods: A quasi-experimental before–after study was conducted on 30 keratoconic eyes from patients aged 10–30 years attending Mayo Hospital, Lahore. Uncorrected and corrected distance visual acuity (logMAR), keratometry (K1, K2, mean K), and pachymetry (central and thinnest) were recorded preoperatively and at six months postoperatively using Galilei G4. Normality was assessed using Shapiro–Wilk test, and comparisons were performed using paired-sample t-test or Wilcoxon signed-rank test as appropriate (p≤0.05). Results: Mean age was 21.19±6.31 years. UDVA improved from 1.00±0.76 to 0.64±0.30 logMAR (mean improvement 0.36; p=0.005) and CDVA improved from 0.51±0.48 to 0.28±0.26 logMAR (mean improvement 0.23; p=0.001). K1, K2, and mean K increased significantly (p=0.001 for all). Central and mean pachymetry remained stable (p>0.05), with a borderline non-significant reduction in thinnest pachymetry (p=0.056). Conclusion: Epithelium-on accelerated CXL resulted in significant visual improvement with pachymetric stability at six months, while keratometric indices increased, warranting structured tomographic monitoring over longer follow-up.