A new method based on polarization-sensitive optical coherence tomography (PS-OCT) is introduced to determine the polarization properties of human retinal vessel walls, in vivo. Measurements were obtained near the optic nerve head of three healthy human subjects. The double pass phase retardation per unit depth (DPPR/UD), which is proportional to the birefringence, is higher in artery walls, presumably because of the presence of muscle tissue. Measurements in surrounding retinal nerve fiber layer tissue yielded lower DPPR/UD values, suggesting that the retinal vessel wall tissue near the optic nerve is not covered by retinal nerve fiber layer tissue (0.43°/µm vs. 0.77°/µm, respectively). Measurements were obtained from multiple artery-vein pairs, to quantify the different polarization properties. Measurements were taken along a section of the vessel wall, with changes in DPPR/UD up to 15%, while the vessel wall thickness remained relatively constant. A stationary scan pattern was applied to determine the influence of involuntary eye motion on the measurement, which was significant. Measurements were also analyzed by two examiners, with high inter-observer agreement. The measurement repeatability was determined with measurements that were acquired during multiple visits. An improvement in accuracy can be achieved with an ultra-broad-bandwidth PS-OCT system since it will provide more data points in-depth, which reduces the influence of discretization and helps to facilitate better fitting of the birefringence data.
Bibliographical noteFunding Information:
Acknowledgments. H.A. and Q.W. acknowledge the financial support of the Australian Government International Research Training Program (RTP) Fee Offset and University Postgraduate Award (UPA) scholarships. M.J.H. would like to acknowledge the financial support of the University Postgraduate Award (UPA), SIRF scholarship and funding through the Ideas Grant from the National Australian Health and Medical Research (NHMRC) Council (APP1180854). S.V.J. acknowledges the financial support from the University Postgraduate Award (UPA) and Graduate Woman (WA) Research Scholarships. B.C. and C.J. acknowledge funding through the Brain Pool Program from the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2019H1D3A2A02101784).
Australian National Health and Medical Research Council APP1180854; National Research Foundation of Korea (2019H1D3A2A02101784); University of Western Australia.
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All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics