Spectral oximetry assessed with high-speed ultra-high-resolution optical coherence tomography

We use Fourier domain optical coherence tomography (OCT) data to assess retinal blood oxygen saturation. Three-dimensional disk-centered retinal tissue volumes were assessed in 17 normal healthy subjects. After removing DC and low-frequency a-scan components, an OCT fundus image was created by integ...

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Bibliographic Details
Main Authors: Kagemann, Larry, Wollstein, Gadi, Wojtkowski, Maciej, Ishikawa, Hiroshi, Townsend, Kelly A., Gabriele, Michelle L., Srinivasan, Vivek J., Fujimoto, James G., Schuman, Joel S.
Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Format: Article
Language:en_US
Published: SPIE 2014
Online Access:http://hdl.handle.net/1721.1/87641
https://orcid.org/0000-0002-0828-4357
Description
Summary:We use Fourier domain optical coherence tomography (OCT) data to assess retinal blood oxygen saturation. Three-dimensional disk-centered retinal tissue volumes were assessed in 17 normal healthy subjects. After removing DC and low-frequency a-scan components, an OCT fundus image was created by integrating total reflectance into a single reflectance value. Thirty fringe patterns were sampled; 10 each from the edge of an artery, adjacent tissue, and the edge of a vein, respectively. A-scans were recalculated, zeroing the DC term in the power spectrum, and used for analysis. Optical density ratios (ODRs) were calculated as ODR[subscript Art] = ln(Tissue[subscript 855]/Art[subscript 855])/ln(Tissue[subscript 805]/Art[subscript 805) and ODR[subscript Vein] = ln(Tissue[subscript 855]/Vein[subscript 855])/ln(Tissue[subscript 805]/Vein[subscript 805]) with Tissue, Art, and Vein representing total a-scan reflectance at the 805- or 855-nm centered bandwidth. Arterial and venous ODRs were compared by the Wilcoxon signed rank test. Arterial ODRs were significantly greater than venous ODRs (1.007 ± 2.611 and −1.434 ± 4.310, respectively; p = 0.0217) (mean±standard deviation). A difference between arterial and venous blood saturation was detected. This suggests that retinal oximetry may possibly be added as a metabolic measurement in structural imaging devices.