Inner ocular blood flow responses to an acute decrease in blood pressure in resting humans

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

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Whether inner ocular vessels have an autoregulatory response to acute fluctuations in blood pressure is unclear. We tried to examine the validity of acute hypotension elicited by thigh-cuff release as to assess the dynamic autoregulation in the ocular circulation. Blood flow velocity in the superior nasal and inferior temporal retinal arterioles, and in the retinal and choroidal vasculature were measured with the aid of laser speckle flowgraphy before and immediately after an acute decrease in blood pressure in 20 healthy subjects. Acute hypotension was induced by a rapid release of bilateral thigh occlusion cuffs that had been inflated to 220 mmHg for 2 min. The ratio of the relative change in retinal and choroidal blood flow velocity to the relative change in mean arterial blood pressure (MAP) was calculated. Immediately after cuff release, the MAP and blood flows in the all ocular target vessels decreased significantly from the baseline values obtained before thigh-cuff release. The ratio of the relative change in inner ocular blood flow velocity to that in the MAP exceeded 1% / %mmHg. An explicit dynamic autoregulation in inner ocular vessels cannot be demonstrated in response to an acute hypotension induced by the thigh-cuff release technique.

Original languageEnglish
Article number219
Pages (from-to)219-230
Number of pages12
JournalPhysiological Measurement
Volume36
Issue number2
DOIs
Publication statusPublished - 2015 Feb 1

Keywords

  • Autoregulation
  • Choroidal circulation
  • Ocular blood flow
  • Retinal circulation

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Physiology (medical)
  • Medicine(all)

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