Prevalence of sleep/wake disorders in persons with blindness.
Blind individuals are not only handicapped by their loss of vision, but are also affected because the loss of sight may have a secondary impact on functioning of their biological clock. The objective of the present study was to determine the impact of visual loss on sleep/wake disorders. A prospective 48-item questionnaire survey was distributed to blind individuals through the French Association Valentin Haüy, which serves blind persons. A control group matched by age, sex, geographical location and professional activity/non-activity was obtained from a panel of 20000 households representative of the French population, and this group also completed the questionnaire. From a potential blind population of 1500 subjects, 1073 questionnaires (71.5%) were completed and usable for analysis, and from a potential 1000 control subjects, 794 (79. 4%) of the questionnaires were returned and analysed. Criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, 4th revision, and the International Classification of Sleep/Wake Disorders (1990) were used to determine pathology. Individuals determined to be 'totally blind' and 'almost blind' (i.e. with less than 10% vision left in only one eye) presented a significantly higher occurrence of sleep/wake disorders than controls. Nocturnal sleep disruption, daytime somnolence, and (to a lesser degree) a 'free-running' condition are significantly more common in blind individuals. There is an increased use of sleeping pills, and a higher incidence of inappropriate involuntary daily naps. In conclusion, individuals with blindness report a significant curtailment of total sleep time and hence resulting daytime somnolence, which impacts on daytime activities. A 'free-running' condition is also a common sleep/wake impairment that may compound the handicap of blindness.
Leger
D
D
Centre du Sommeil, Hotel Dieu, 75001 Paris, France and Stanford Sleep Disorders Center, Stanford University, 401 Quarry Road, Suite 3301A, Stanford, CA 94305, USA.
Guilleminault
C
C
Defrance
R
R
Domont
A
A
Paillard
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001766:Blindness / Q000150:complications* / Q000453:epidemiology; D005221:Fatigue; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D011594:Psychometrics; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology; D012913:Snoring / Q000209:etiology