title: Comparisons of Objective Sleep Quality Between Elderly Individuals With and Without Cataract Surgery: A Cross-Sectional Study of the HEIJO-KYO Cohort.
abstract: BACKGROUND
  Cataract surgery (CS) drastically increases the capacity for light reception to the retina. Several previous studies have suggested the beneficial effect of CS on subjectively measured sleep quality; however, the association between CS and objectively measured sleep quality remains uncertain.
  
  
  METHODS
  To evaluate the association between CS and objectively measured sleep quality in home settings, we conducted a cross-sectional study in 1037 elderly individuals (mean age, 71.9 years). We evaluated actigraphically measured sleep quality, urinary 6-sulfatoxymelatonin excretion, and ambulatory light levels, in addition to CS status.
  
  
  RESULTS
  The CS group (n = 174) showed significantly higher sleep efficiency and shorter wake after sleep onset than the no CS group (n = 863), even after adjustment for age, gender, body mass index, current smoking status, alcohol consumption, hypertension, diabetes, sleep medication, bedtime, rising time, daytime physical activity, daytime and nighttime light exposure, and urinary 6-sulfatoxymelatonin excretion (sleep efficiency: 85.8% in the CS group vs 84.4% in the no CS group, P = 0.042; wake after sleep onset: 45.7 min vs 50.6 min, respectively, P = 0.033). In contrast, urinary 6-sulfatoxymelatonin excretion, sleep onset latency, total sleep time, and sleep-mid time did not differ significantly between the CS and no CS groups.
  
  
  CONCLUSIONS
  Among a community-dwelling elderly population, CS is significantly associated with objectively measured sleep quality, but urinary levels of melatonin metabolite do not differ between individuals with and without CS. These associations are independent of daily light exposure profiles.
authors.affiliation: Department of Community Health and Epidemiology, Nara Medical University School of Medicine.
authors.forename: Kenji
authors.initials: K
authors.lastname: Obayashi
authors.forename: Keigo
authors.initials: K
authors.lastname: Saeki
authors.forename: Kimie
authors.initials: K
authors.lastname: Miyata
authors.forename: Tomo
authors.initials: T
authors.lastname: Nishi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tone
authors.forename: Nahoko
authors.initials: N
authors.lastname: Ogata
authors.forename: Norio
authors.initials: N
authors.lastname: Kurumatani
mesh_terms: D056044:Actigraphy; D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008029:Lighting / Q000706:statistics & numerical data; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000652:urine; D008875:Middle Aged; D012890:Sleep / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin