Ocular blood flow decreases during passive heat stress in resting humans

Tsukasa Ikemura, Akane Miyaji, Hideaki Kashima, Yuji Yamaguchi, Naoyuki Hayashi*


研究成果: Article査読

4 被引用数 (Scopus)


Background: Heat stress induces various physiological changes and so could influence ocular circulation. This study examined the effect of heat stress on ocular blood flow.Findings: Ocular blood flow, end-tidal carbon dioxide (PETCO2) and blood pressure were measured for 12 healthy subjects wearing water-perfused tube-lined suits under two conditions of water circulation: (1) at 35°C (normothermia) for 30 min and (2) at 50°C for 90 min (passive heat stress). The blood-flow velocities in the superior temporal retinal arteriole (STRA), superior nasal retinal arteriole (SNRA), and the retinal and choroidal vessels (RCV) were measured using laser-speckle flowgraphy. Blood flow in the STRA and SNRA was calculated from the integral of a cross-sectional map of blood velocity. PETCO2 was clamped at the normothermia level by adding 5% CO2 to the inspired gas. Passive heat stress had no effect on the subjects' blood pressures. The blood-flow velocity in the RCV was significantly lower after 30, 60 and 90 min of passive heat stress than the normothermic level, with a peak decrease of 18 ± 3% (mean ± SE) at 90 min. Blood flow in the STRA and SNRA decreased significantly after 90 min of passive heat stress conditions, with peak decreases of 14 ± 3% and 14 ± 4%, respectively.Conclusion: The findings of this study suggest that passive heat stress decreases ocular blood flow irrespective of the blood pressure or arterial partial pressure of CO2.

ジャーナルJournal of physiological anthropology
出版ステータスPublished - 2013 12月 6

ASJC Scopus subject areas

  • 人的要因と人間工学
  • 生理学
  • 整形外科およびスポーツ医学
  • 人類学
  • 公衆衛生学、環境および労働衛生
  • 生理学(医学)


「Ocular blood flow decreases during passive heat stress in resting humans」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。