Cross-sectional study of intraocular cataract lens replacement, circadian rest-activity rhythms, and sleep quality in older adults

Study Objectives Age-related cataract decreases light transmission at the most sensitive spectrum for circadian photoentrainment, with negative ramifications for human health. Here, we assessed whether intraocular lens replacement (IOL) in older patients with previous cataract was associated with increased stability and amplitude of circadian rest-activity rhythms, and improved sleep quality. Methods Our cross-sectional study included sixteen healthy older individuals without ocular diseases (controls; 55-80 years; 63.6 +/- 5.6y; 8 women) and 13 patients with previous cataract and bilateral IOL (eight with blue-blocking [BB] lens and five with ultraviolet-only [UV] blocking lens; 55-80 years; 69.9 +/- 5.2y; 9 women). The study comprised three weeks of at home rest-activity assessments using wrist-worn actigraphs, and each week preceded a laboratory protocol. Primary outcomes were actigraphy-derived interdaily stability, intradaily variability, and relative amplitude of circadian rest-activity rhythms. Secondary outcomes were actigraphy-assessed sleep quality (i.e. time in bed, sleep duration, sleep efficiency, mean wake bout time and fragmentation index). Results Patients with IOL had significantly higher interdaily stability (Group effect: pFDR =.001), but not intradaily variability (Group effect: pFDR = n.s.), and significantly higher relative amplitude of rest-activity rhythms (Group effect: pFDR < .001). Moreover, patients with IOL had significantly higher activity levels during the day and lower levels during the evening, as compared to healthy older controls (Group effect: pFDR = .03). Analyses of actigraphy-derived sleep parameters yielded no significant differences across groups (Group effect: all pFDR > .1). Conclusions Our cross-sectional study suggests that enhancing spectral lens transmission in patients with cataract may benefit their circadian health.