title: Systemic autonomic function in subjects with primary angle-closure glaucoma: a comparative study of symptomatic and asymptomatic disease presentation.
abstract: BACKGROUND
  Autonomic dysfunction is thought to be a contributory factor in primary angle-closure glaucoma (PACG) by precipitating pupil block in anatomically predisposed eyes. This study aimed to compare systemic autonomic function between subjects who had suffered a previous episode of acute angle closure (symptomatic PACG), those who had asymptomatic PACG, and age and sex-matched controls.
  
  
  METHODS
  Tests for systemic parasympathetic function included the heart-rate response to standing (30:15 ratio), heart-rate variation during deep breathing, and the ratio of the heart rate at phases IV and II of the Valsalva manoeuvre (Valsalva ratio). For assessment of the sympathetic nervous system, blood pressure was recorded supine and then after 2 and 5 min of standing. A modified sweat test, the sympathetic skin response, was recorded on the palm and sole.
  
  
  RESULTS
  A total of 30 subjects were examined: eight previous symptomatic PACG, eight asymptomatic PACG and 14 control subjects. The mean ages were similar, and all except one subject were Chinese. None of the subjects had evidence of systemic dysautonomia. There was no significant difference found between the groups for the 30:15 ratio, heart-rate variation during deep respiration and the Valsalva ratio. No significant orthostatic hypotension was detected in subjects with PACG. Abnormal sympathetic skin response was not more common in PACG subjects compared to control subjects.
  
  
  CONCLUSIONS
  This study identified no systemic autonomic dysfunction in people with PACG.
authors.affiliation: The Eye Institute, Tan Tock Seng Hospital, Singapore, Singapore. Vernon_Yong@ttsh.com.sg
authors.forename: Vernon K Y
authors.initials: VK
authors.lastname: Yong
authors.forename: Thirugnanam
authors.initials: T
authors.lastname: Umapathi
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
authors.forename: Nigel C K
authors.initials: NC
authors.lastname: Tan
authors.forename: Jong-Jian
authors.initials: JJ
authors.lastname: Lee
authors.forename: Geok-Cheng
authors.initials: GC
authors.lastname: Liew
authors.forename: Chee-Chew
authors.initials: CC
authors.lastname: Yip
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Foster
authors.forename: Paul T K
authors.initials: PT
authors.lastname: Chew
mesh_terms: D001341:Autonomic Nervous System / Q000502:physiology; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged