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Updated: Mar 7, 2026
Doppler Optical Coherence Tomography of Retinal Circulation
Published on: September 18, 2012
Effect of Diffuse Luminance Flicker Light Stimulation on Total Retinal Blood Flow Assessed With Dual-Beam
Gerold C Aschinger1, Leopold Schmetterer2, Klemens Fondi3
1Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria 2Institute of Applied Physics, Vienna University of Technology, Vienna, Austria.
Purpose:
We assess the increase in total retinal blood flow (TRBF) induced by flicker stimulation of the human retina in vivo and investigate the flicker induced hyperemia by means of a vascular flow model of the retinal circulation to study neurovascular coupling (NC).
Methods:
In six healthy subjects, TRBF was measured before and during stimulation with diffuse luminance flicker. Blood flow velocities in retinal vessels were measured via dual-beam bidirectional Doppler Fourier-domain optical coherence tomography (FD-OCT), retinal vessel diameters were assessed based on FD-OCT phase data. This allowed for the calculation of TRBF before and during visual stimulation. Additionally, a mathematical flow model for the retinal vasculature was adapted to study the implications of diameter variations on retinal perfusion. Measured and simulated perfusion was compared to draw conclusions on the diameter variations in different layers of the vascular tree.
Results:
The measured mean baseline flow was 36.4 ± 6.5 microl/min while the mean flow during flicker stimulation was 53.4% ± 8.3 microl/min. The individual increase in TRBF during flicker stimulation ranged between 34% and 66%. The average increase in TRBF over all measured subjects was 47.6% ± 12.6%.
Conclusions:
Dual-beam bidirectional Doppler FD-OCT allowed quantifying NC in the human retina in vivo and may be a promising method for monitoring alterations in NC caused by various pathologies. The comparison of the measured data with the results obtained in the simulated vasculature indicates that the vasodilation induced by NC is more pronounced in smaller vessels.
