Factors affecting visual acuity after accelerated crosslinking in patients with progressive keratoconus

The present study aimed to report the outcomes of patients with progressive keratoconus who were treated via accelerated crosslinking (CXL) 6 months earlier and to determine the factors that promoted improved visual acuity after treatment.

This retrospective study included 35 eyes of 34 patients with progressive keratoconus who underwent CXL. Topographical measurements were obtained preoperatively and in the first, third, and sixth months postoperatively using a rotating Scheimpflug camera. The uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), flat keratometry (K) value (K1), steep K value (K2), average K value (avgK), topographic cylindrical value (Cyl), apical keratoscopy front (AKf), apical keratoscopy back (AKb), symmetry index front (SIf), symmetry index back (SIb), and thinnest point of the cornea (ThkMin) were recorded.

At the 6-month follow-up, the mean UCVA and BCVA values were improved, and the K values remained stable. Statistically significant decreases in AKf (p=0.04) and the thinnest point of the cornea (p=0.001) and a statistically significant increase in AKb (p=0.01) were observed. A correlation analysis revealed that the preoperative BCVA, UCVA, K1, K2, avgK, AKf, and AKb values significantly affected visual acuity at the 6-month follow-up.

Accelerated CXL is an effective treatment for the prevention or even reversal of keratoconus progression. The preoperative K values and apexes of the anterior and posterior cornea were found to affect visual acuity at 6 months after accelerated CXL. Both AKb steepening and AKf flattening appear to be important factors in the stabilization of keratometric values and improvement of visual outcomes.