Factors affecting outcomes of corneal collagen crosslinking treatment

To assess the effects of preoperative patient characteristics on clinical outcomes of corneal crosslinking (CXL) treatment in patients with progressive keratoconus.

This retrospective study comprised 96 eyes of 96 patients who had unilateral CXL treatment for progressive keratoconus. All patients underwent a complete ophthalmological examination and corneal topography at baseline and 1 year. Subgroup analyses were performed according to the age (<30 and ≥ 30 years), gender, preoperative corrected distance visual acuity (CDVA, <0.3 and ≥ 0.3 logMAR (log of the minimum angle of resolution)), preoperative maximum keratometry (K, <54 and ≥ 54 D), baseline topographic cone location (central, paracentral, and peripheral), and preoperative thinnest pachymetry (<450 and ≥ 450 μm) to determine the associations between preoperative patient characteristics and outcomes (changes in visual acuity and maximum keratometry) of CXL treatment.

In the entire study population, mean CDVA and maximum K significantly improved after CXL treatment (P<0.001). Patients with a preoperative CDVA of 20/40 Snellen equivalent or worse (≥ 0.3 logMAR) experienced more visual improvement after CXL treatment (P<0.001). However, an age ≥ 30 years and a baseline thinnest pachymetry less than 450 μm were found significantly associated with more flattening in maximum keratometry (P=0.024, P=0.005 respectively). Gender, preoperative maximum K, and baseline topographic cone location did not show significant effect on postoperative visual acuity and maximum keratometry (P>0.05).

In patients with progressive keratoconus, age, baseline visual acuity, and baseline thinnest pachymetry seem to affect the success of the CXL treatment.