Measuring oxygen saturation in retinal and choroidal circulations in rats using visible light optical coherence tomography angiography

Siyu Chen, Ji Yi, Hao F. Zhang

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

Visible light optical coherence tomography (vis-OCT) has demonstrated its capability of measuring vascular oxygen saturation (sO2) in vivo. Enhanced by OCT angiography, the signal from microvasculature can be further isolated and directly used for sO2 extraction. In this work, we extended the theoretical formulation for OCT angiography-based oximetry by incorporating the contribution from motion contrast enhancement. We presented a new method to eliminate the associated confounding variables due to blood flow. First, we performed in vitro experiments to verify our theory, showing a stable spectral derivative within the selected wavelength bands for sO2 extraction. Then, we tested our method in vivo to measure retinal sO2 in rats inhaling different gas mixtures: normal air, 5% CO2, pure O2, and 10% O2. Absolute sO2 values in major arterioles and venules in the retinal circulation can be accurately measured. In addition, we demonstrated the relative changes of sO2 can be measured non-invasively from choriocapillaris immediately underneath the retinal pigmented epithelium (RPE) in rodents.

Original languageEnglish (US)
Pages (from-to)2840-2853
Number of pages14
JournalBiomedical Optics Express
Volume6
Issue number8
DOIs
StatePublished - Jul 10 2015

Keywords

  • Blood gas monitoring
  • Functional monitoring and imaging
  • Optical coherence tomography
  • Speckle
  • Spectroscopy

ASJC Scopus subject areas

  • Biotechnology
  • Atomic and Molecular Physics, and Optics

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