Factors Associated With Decreased Quality Of Life In Keratoconus: A Save Sight Keratoconus Registry Study

The objectives of this study were to determine the factors associated with decreased quality of life in keratoconus, and to determine the relationship between the quality-of-life scores and standard clinical variables using the Keratoconus Outcomes Research Questionnaire (KORQ). 

A cross-sectional, real-world study was conducted utilising prospective, web-based Save Sight Keratoconus registry data collected from the routine clinical practice. 

The KORQ was completed by 542 patients with keratoconus (male, 67.7%; mean age, 31.6 years). Keratoconus severity was mild, moderate and severe in 26.3%, 45.0%, and 28.7% of patients, respectively. Rasch analysis was conducted on the KORQ data using the Andrich Rating Scale Model. The univariable analysis included Welch t-test and one-way ANOVA. Associations between visual acuity, keratometry and pachymetry with KORQ scores were evaluated with Pearson’s correlation and multiple regression adjusted for age and gender. 

Activity limitation and Symptoms scales of the KORQ had robust psychometric properties including well-functioning response categories, unidimensionality, excellent measurement precision and satisfactory fit statistics. In a group-wise analysis, the female patients had significantly lower Activity limitation and Symptoms scores. Similarly, the severe keratoconus group had the worst Activity limitation and Symptoms scores. Contact lens wearers had worse KORQ scores than the spectacles wearers. Overall, statistically significant but weak correlations between KORQ scores and visual acuity and keratometry (Kmax and K2) readings (Pearson’s r, 0.11-0.35) were observed. The correlations for Symptoms were weaker than for Activity limitation scores. 

Female gender, contact lens wear, reduced visual acuity, and higher disease severity were associated with worse quality-of-life (activity limitation and symptoms) scores in keratoconus. Although the correlations between clinical and quality-of-life scores were statistically significant, the low magnitudes suggested a complex relationship between clinical parameters and patient-reported outcomes.