title: Choroidal vascular reaction to hand-grip stress in subjects with vasospasm and its relevance in glaucoma.
abstract: OBJECTIVE
  To assess the impact of vascular dysregulation on choroidal blood flow response to the hand-grip test and the relevance of this response to glaucoma.
  
  
  METHODS
  Eighty healthy volunteers underwent a hand-grip test while choroidal blood flow was measured by means of laser Doppler flowmetry. Blood pressure, heart rate, and intraocular pressure (IOP) were monitored. Choroidal blood flow changes were compared between subjects with a positive history of cold hands and control subjects by means of analysis of variance. The relationship of the vascular response to the level of IOP at which progressive damage occurred was analyzed in 21 patients with primary open-angle glaucoma who had progressive damage despite normal or normalized IOP.
  
  
  RESULTS
  Blood pressure and heart rate increased and IOP decreased in response to a hand-grip test. Healthy subjects with a positive history of cold hands (n = 36) demonstrated a decrease in choroidal blood flow during the hand-grip test (mean +/- SD: 13.5 +/- 5.8, 12.2 +/- 6.8, and 13.4 +/- 6.9 AU, at baseline, during the test, and 3 minutes after release, respectively), whereas control subjects (n = 44) demonstrated an inverse (12.5 +/- 8.3, 13.7 +/- 9.4, and 11.9 +/- 7.1 AU, respectively) response pattern (P = 0.039). Glaucoma patients with a decrease of at least 10% in choroidal blood flow during the hand-grip test had lower IOP (14.67 +/- 3.83 and 13.50 +/- 2.59 mm Hg in the right and the left eyes, respectively) compared (P = 0.032) with those without such a decrease (16.54 +/- 3.85 and 16.92 +/- 2.95 mm Hg in the right and the left eyes, respectively).
  
  
  CONCLUSIONS
  A hand-grip test elicits a different blood flow response in subjects with vasospasm compared with control subjects. Damage by glaucoma in patients with a decrease in choroidal blood flow during a hand-grip test may progress at a relatively lower IOP.
authors.affiliation: University Eye Clinic, Basel, Switzerland.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Gugleta
authors.forename: Selim
authors.initials: S
authors.lastname: Orgül
authors.forename: Pascal W
authors.initials: PW
authors.lastname: Hasler
authors.forename: Thierry
authors.initials: T
authors.lastname: Picornell
authors.forename: Doina
authors.initials: D
authors.lastname: Gherghel
authors.forename: Josef
authors.initials: J
authors.lastname: Flammer
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D002829:Choroid / Q000098:blood supply*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007022:Hypotension / Q000503:physiopathology; D007035:Hypothermia / Q000503:physiopathology; D007429:Intraocular Pressure / Q000502:physiology; D007537:Isometric Contraction / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D013312:Stress, Physiological / Q000503:physiopathology*