Impact of corneal collagen cross-linking on vision-related quality of life measured with the keratoconus outcomes research questionnaire (KORQ) in patients with keratoconus

Purpose To assess the impact of corneal collagen cross-linking on self-reported vision-related quality of life (VR-QoL) in keratoconus patients by means of the Keratoconus Outcomes Research Questionnaire (KORQ), a new disease-specific patient reported outcomes measures (PROMs) tool. Methods Patients with progressive keratoconus undergoing corneal collagen cross-linking were consecutively enrolled. Patients completed the KORQ before and after the treatment, at 1, 3 and 6 months. Data were collected regarding the visual acuity and the topographic, aberrometric and pachymetric parameters of both eyes. Patients were also asked to quantify their eye rubbing behavior on a Visual Analogue Scale (VAS) from 0 to 10, before and 6 months after treatment. The KORQ scores were associated with the visual acuity, topographic, aberrometric and pachymetric data by means of the Spearman correlation coefficient. Results The Activity Limitation (AL) subscale score was higher after surgery. Preoperatively, negative correlations were observed between the KORQ AL score and Best Corrected Visual Acuity (logMAR), maximum keratometry, flattest keratometry, steepest keratometry, symmetry index front and higher order aberrations (HOA) of the treatment eye. Postoperatively, we observed a shift toward the fellow eye, with stronger correlation of the KORQ scores with the fellow eye parameters. The Symptoms subscale score correlated with the aberrometric parameters of both eyes at various time points. Statistically significant correlations were observed between the change in KORQ scores and the change in aberrometric parameters. A statistically significant reduction in the eye rubbing behavior was detected (p < 0,0001). Conclusions These results suggest that the corneal cross-linking treatment is effective both in improving the subjective perception of the disease by the patient and in stabilizing the objective indicators of disease progression. Keratometric, aberrometric and visual acuity values showed a significant impact on self-reported VR-QoL. Corneal cross-linking, by halting the worsening of these parameters, may bear a beneficial effect on VR-QoL.