Visual Impairment and Reported Sleep Complaints: A Verification Study

Abstract

Abstract: : Purpose: Recently, we showed a relationship between self–reported visual impairment and sleep complaints in urban older Americans. The present study further explored the relationship between sleep complaints and visual impairment as defined by standard ophthalmic examinations in a community–based sample of older adults. Methods: A total of 70 volunteers from a biracial cohort participated in the study (mean age = 68.27 ± 5.97 years); 73% were female. Participants completed baseline questionnaires soliciting information on sociodemographic characteristics and physical health. The physical health questionnaire included questions on whether or not the volunteer experienced sleeping difficulties and visual impairment. Volunteers underwent an eye exam. Ophthalmic instruments included the nerve fiber layer analyzer, visual field testing, Snellen chart, fundus photography and tonometry. Results: 46% of the participants reported visual impairment at baseline. 27% were visually impaired according to American criteria. 20% of the volunteers received an eye diagnosis; 5.8% had glaucoma; 7.2%, cataract; and 7.2%, ocular hypertension. To verify whether volunteers with a sleep complaint (i.e., difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, or daytime napping) also had eye dysfunctions, Fisher’s Exact tests were used. Results indicated that those (35%) who reported napping were more likely to receive an eye diagnosis vs. those that did not (12%) [Fisher’s value = 4.45, df = 69, p = 0.04]. No significant relationships were found between eye diagnosis and the other sleep complaints. Conclusions: This study showed that individuals with eye impairment may not necessarily experience difficulty initiating sleep, difficulty maintaining sleep, or early morning awakening. The finding of a greater likelihood of daytime naps among volunteers with an eye diagnosis is that older adults with visual impairment may be spending more time indoors, thus providing them with a greater opportunity for napping. In addition, eye diseases might diminish light–induced regulation of the sleep–wake cycle. Thus, the sleep–wake period would be redistributed throughout the 24–hr day, such that sleep is attempted both at night and during daytime to compensate for sleep loss to nocturnal awakenings. Prior research has shown that some older adults take naps both in the afternoon/evening as well as in the morning after final awakening without their awareness.

Keywords: circadian rhythms • aging • clinical (human) or epidemiologic studies: prevalence/incidence