title: Effects of transient mild systemic hypoxia on the pulsatile choroidal blood flow in healthy young human adults.
abstract: OBJECTIVE
  To investigate the effects of transient mild systemic hypoxia on the pulsatile ocular blood flow (POBF) in the healthy young adult.
  
  
  METHODS
  Two measurements of the intraocular pressure (IOP) pulses, used to derive the POBF, were recorded from 19 subjects before, during, and after breathing 12% oxygen in nitrogen. Many physiological variables were also assessed throughout testing.
  
  
  RESULTS
  Transient mild systemic hypoxia decreased the hemoglobin oxygen saturation and end-tidal carbon dioxide, increased the heart rate, but did not change the respiratory rate, systemic blood pressure, or ocular perfusion pressure. Mild systemic hypoxia decreased the intraocular pulse volume and the systolic and diastolic times but did not alter the pulse amplitude or the POBF. The IOP was not altered during mild systemic hypoxia.
  
  
  CONCLUSIONS
  The absence of change in the POBF during transient mild systemic hypoxia indicated that the global pulsatile choroidal blood flow was not vulnerable to the effects of this transient mild systemic hypoxic stress in the healthy young adult.
authors: School of Optometry, University of Montreal, C.P. 6128, Succursale Centre-Ville, Montreal, P. Quebec, Canada H3C 3J7. helene.kergoat@umontreal.ca
authors: Hélène
authors: H
authors: Kergoat
authors: Julie-Andrée
authors: JA
authors: Marinier
authors: John V
authors: JV
authors: Lovasik
mesh_terms: D000328:Adult; D001158:Arteries; D002245:Carbon Dioxide; D002829:Choroid / Q000098:blood supply*; D003971:Diastole; D005260:Female; D006339:Heart Rate; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010100:Oxygen / Q000097:blood; D011673:Pulsatile Flow; D011674:Pulse; D012039:Regional Blood Flow; D013599:Systole; D013990:Tidal Volume; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen