Total retinal blood flow measurement by three beam Doppler optical coherence tomography

Abstract

We present measurements of total retinal blood flow in healthy volunteers using a three beam Doppler optical coherence tomography (D-OCT) technique. This technology has the advantage of a precise determination of the flow vector without the use of any a-priori information on the vessel geometry. Circular D-OCT scans around the optic disc were recorded and venous as well as arterial total blood flow was determined and compared for each subject. The reproducibility of the method was assessed in 6 subjects by repeated measurements. Only small deviations of around 6% between the measurements were found which indicates the high precision of the proposed method. Werkmeister, "Blood flow velocity vector field reconstruction from dual-beam bidirectional Doppler OCT measurements in retinal veins," Biomed. Opt. Express 6(5), 1599-1615 (2015). 38. C. E. Riva, J. E. Grunwald, S. H. Sinclair, and B. L. Petrig, "Blood velocity and volumetric flow rate in human retinal vessels," Invest. Ophthalmol. Vis. Sci. 26(8), 1124-1132 (1985). 39. J. P. Garcia, Jr., P. T. Garcia, and R. B. Rosen, "Retinal blood flow in the normal human eye using the canon laser blood flowmeter," Ophthalmic Res. 34(5), 295-299 (2002

Precision analysis and optimization in phase decorrelation OCT velocimetry

“…It should be emphasized here that Eq. (15) shows that the overlap integral is independent of the distance of the scattering volume to the focal plane, as derived by Popov et al [22] and previously demonstrated experimentally by Weiss et al [28]. The remaining calculation of the expected distribution function of phase differences is analogous to Vakoc et al [24] with one difference: In [24] only lateral motion was considered and investigated.…”

“…Doppler OCT has the disadvantage that only the velocity component parallel to the propagation direction of the light can be measured. Several attempts have been made in the past years to overcome this limitation, among these: Doppler OCT with multiple directions of illumination/detection [15,16], (complex) speckle decorrelation [17][18][19] and Doppler mean and bandwidth analysis [20,21]. Doppler OCT with multiple directions of illumination requires a significant increase in system complexity [15,16], which can be a limiting factor especially if other functionalities should be incorporated.…”

“…Several attempts have been made in the past years to overcome this limitation, among these: Doppler OCT with multiple directions of illumination/detection [15,16], (complex) speckle decorrelation [17][18][19] and Doppler mean and bandwidth analysis [20,21]. Doppler OCT with multiple directions of illumination requires a significant increase in system complexity [15,16], which can be a limiting factor especially if other functionalities should be incorporated. (Complex) speckle decorrelation and Doppler mean and bandwidth analysis requires in general acquisition of large data ensembles for each voxel and velocity estimation [17][18][19].…”

Key Developments for Partial Coherence Biometry and Optical Coherence Tomography in the Human Eye Made in Vienna

“…118 This changed with the introduction of FD OCT that brought a strong impetus for DOCT. 83,[119][120][121][122][123] Dynamic DOCT could resolve pulsatile flow in a reliable quantitative manner and without prior knowledge on vessel geometry, based on multibeam [124][125][126][127][128] or volumeacquisition schemes. [129][130][131] The high acquisition speed allowed furthermore for novel flexible scanning schemes to obtain 3D angiographic maps without compromising overall imaging time.…”

Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography

“…[3][4][5] Alternatively, postimage processing methods were commonly applied to circumvent the need for complex hardware modifications. For example, h z was retrieved by connecting the center of vessels between two cross-sectional flow images.…”