Abstract
STUDY OBJECTIVES: This questionnaire-based cross-sectional study was conducted (1) to estimate the prevalence of sleep-related problems, and (2) to explore factors associated with lower physical/mental quality of life (QOL), particularly addressing sleep-related problems among Japanese visually impaired people. METHODS: This nationwide questionnaire-based survey was administered to visually impaired individuals through the Japan Federation of the Blind. Visually impaired individuals without light perception (LP) (n = 311), those with LP (n = 287), and age-matched and gender-matched controls (n = 615) were eligible for this study. Study questionnaires elicited demographic information, and information about visual impairment status, sleep-related problems, and health-related quality of life. RESULTS: Visually impaired individuals with and without LP showed higher prevalence rates of irregular sleep-wake patterns and difficulty maintaining sleep than controls (34.7% and 29.4% vs. 15.8%, 60.1% and 46.7% vs. 26.8%, respectively; p < 0.001). These sleep-related problems were observed more frequently in visually impaired individuals without LP than in those with LP. Non-restorative sleep or excessive daytime sleepiness was associated with lower mental/physical QOL in visually impaired individuals with LP and in control subjects. However, visually impaired individuals without LP showed irregular sleep-wake pattern or difficulty waking up at the desired time, which was associated with lower mental/physical QOL. CONCLUSIONS: Sleep-related problems were observed more frequently in visually impaired individuals than in controls. Moreover, the rates of difficulties were higher among subjects without LP. Sleep-related problems, especially circadian rhythm-related ones, can be associated with lower mental/physical QOL in visually impaired individuals without LP.