title: Circadian rhythm of autonomic nervous function in patients with normal-tension glaucoma compared with normal subjects using ambulatory electrocardiography.
abstract: OBJECTIVE
  To compare circadian rhythm of autonomic nervous function in patients with normal-tension glaucoma with subjects with normal eyes.
  
  
  METHODS
  Thirty-two patients with normal-tension glaucoma and 32 age-matched normal subjects who had no history of systemic disorders and no currently treated systemic disorders, especially diseases of the autonomic nervous system, were studied. An ambulatory electrocardiogram was installed that recorded heartbeats for 48 hours. Low-frequency and high-frequency values were calculated as markers of the autonomic nervous system status based on heart-rate variability using a power-spectrum analysis.
  
  
  RESULTS
  The low-frequency values of patients with normal-tension glaucoma during the spans of an active day and a resting night were significantly greater than those of normal subjects, and this difference was emphasized during the night resting span. However, the high-frequency values of patients with normal-tension glaucoma were similar to those of normal subjects. The normal subjects showed a significant age-related decrease in all investigated parameters except the low-frequency values during the resting span. However, the patients with normal-tension glaucoma showed a significant age-related decrease only in low-frequency values during the active day. Patients with normal-tension glaucoma with progressive visual field defects showed much greater values than other cases, although the values were not significantly different.
  
  
  CONCLUSIONS
  These results indicate that a disturbance of the circadian rhythm of the autonomic nervous system may exist in patients with normal-tension glaucoma.
authors.affiliation: Department of Ophthalmology, Yamanashi Medical University, Tamaho, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kashiwagi
authors.forename: T
authors.initials: T
authors.lastname: Tsumura
authors.forename: H
authors.initials: H
authors.lastname: Ishii
authors.forename: H
authors.initials: H
authors.lastname: Ijiri
authors.forename: K
authors.initials: K
authors.lastname: Tamura
authors.forename: S
authors.initials: S
authors.lastname: Tsukahara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001341:Autonomic Nervous System / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012890:Sleep; D014794:Visual Fields