Effects of transient mild systemic hypoxia on the pulsatile choroidal blood flow in healthy young human adults.
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.
Kergoat
Hélène
H
School of Optometry, University of Montreal, C.P. 6128, Succursale Centre-Ville, Montreal, P. Quebec, Canada H3C 3J7. helene.kergoat@umontreal.ca
Marinier
Julie-Andrée
JA
Lovasik
John V
JV
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
D002245:Carbon Dioxide; D010100:Oxygen