Functional optical coherence tomography at altitude: retinal microvascular perfusion and retinal thickness at 3,800 meters

Jacquie Baker, Mohammad A. Safarzadeh, Anthony V. Incognito, Nicholas G. Jendzjowsky, Glen E. Foster, Jordan D. Bird, Satish R. Raj, Trevor A. Day, Caroline A. Rickards, Natalia Zubieta-DeUrioste, Usman Alim, Richard J.A. Wilson

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Cerebral hypoxia is a serious consequence of several cardiorespiratory illnesses. Measuring the retinal microvasculature at high altitude provides a surrogate for cerebral microvasculature, offering potential insight into cerebral hypoxia in critical illness. In addition, although sex-specific differences in cardiovascular diseases are strongly supported, few have focused on differences in ocular blood flow. We evaluated the retinal microvasculature in males (n = 11) and females (n = 7) using functional optical coherence tomography at baseline (1,130 m) (day 0), following rapid ascent (day 2), and prolonged exposure (day 9) to high altitude (3,800 m). Retinal vascular perfusion density (rVPD; an index of total blood supply), retinal thickness (RT; reflecting vascular and neural tissue volume), and arterial blood were acquired. As a group, rVPD increased on day 2 versus day 0 (P < 0.001) and was inversely related to PaO2 (R2 = 0.45; P = 0.006). By day 9, rVPD recovered to baseline but was significantly lower in males than in females (P = 0.007). RT was not different on day 2 versus day 0 (P > 0.99) but was reduced by day 9 relative to day 0 and day 2 (P < 0.001). RT changes relative to day 0 were inversely related to changes in PaO2 on day 2 (R2 = 0.6; P = 0.001) and day 9 (R2 = 0.4; P = 0.02). RT did not differ between sexes. These data suggest differential time course and regulation of the retina during rapid ascent and prolonged exposure to high altitude and are the first to demonstrate sex-specific differences in rVPD at high altitude. The ability to assess intact microvasculature contiguous with the brain has widespread research and clinical applications.

Original languageEnglish
Pages (from-to)534-545
Number of pages12
JournalJournal of Applied Physiology
Issue number3
StatePublished - Sep 2022


  • cerebral microvasculature
  • functional optical coherence tomography
  • high altitude
  • hypoxia
  • retinal microvasculature


Dive into the research topics of 'Functional optical coherence tomography at altitude: retinal microvascular perfusion and retinal thickness at 3,800 meters'. Together they form a unique fingerprint.

Cite this