The disease burden of keratoconus in patients' lives: Comparisons to a Japanese normative sample

PURPOSE. Keratoconus is a chronic, noninflammatory, degenerative disease of the cornea that has an onset in young adulthood. The objective of this study was to evaluate vision-related quality of life (VR-QOL) in patients with keratoconus by using the Japanese version of the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25). METHODS. Forty-five patients diagnosed with keratoconus at the Keio University School of Medicine were enrolled. Patients were divided into three subgroups according to corrected visual acuity. Group A included patients whose best-corrected visual acuity was at least 20/20 in both eyes. Group B included patients with a best-corrected visual acuity of at least 20/20 in only one eye. Group C included patients whose best-corrected visual acuity was worse than 20/20 in both eyes. Thirty-six age-matched subjects were recruited as control subjects. The Japanese version of the NEI-VFQ-25 was administered to each subject. RESULTS. All NEI-VFQ-25 subscale scores were significantly lower (P<0.05) in patients with keratoconus than in the control subjects. Subscales evaluating general health, ocular pain, and vision-specific mental health showed particularly low values. Among patients with keratoconus, every subscale score other than color vision correlated with corrected visual acuity. CONCLUSIONS. The results support that and describe how multidimensional visual function and VR-QOL are impaired in patients with keratoconus, including those with normal visual acuity. Ophthalmologists and other clinicians should carefully evaluate and address the full range of quality of life issues that may affect patients with keratoconus.