Purchase this article with an account.
Richard Haindl, Wolfgang Karl Trasischker, Bernhard Baumann, Michael Pircher, Christoph K Hitzenberger; Measurement of absolute velocity and flow of moving scatterers in retinal veins using 3-Beam Doppler Optical Coherence Tomography. Invest. Ophthalmol. Vis. Sci. 2014;55(13):218.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine the capability of a new three-beam Doppler OCT (D-OCT) system to measure absolute velocity, flow and flow vector orientation of blood cells in retinal vessels without a-priori knowledge of the vessel orientation.
A new 3 beam D-OCT system was developed. The system provides illumination at 3 different angles. Therefore 3 velocity vector components can be measured simultaneously and the absolute velocity, the flow and the flow vector orientation through a vessel can be calculated. For each channel an individual SLD source with a central wavelength at 840 nm was used. The beams were aligned as an equilateral triangle with the 3 beams placed on the edges of the triangle. The D-OCT system is spectrometer (SD) based. A two axis gimbal-less MEMS mirror was used for scanning and the system was operated at 20,000 A-scans/s. Eyes of healthy subjects were imaged and velocity profiles, mean absolute velocity, flow and flow vector orientation of moving blood cells in retinal veins were obtained.
Figure 1 shows an example of a flow measurement in a retinal vein. Repeated measurements in this vessel gave an absolute blood flow velocity, averaged over the cross section, of 14.8 ± 0.5 mm/s (mean ± SD), a blood flow of 0.3 ± 0.06 µl/s, and an orientation of the velocity vector of 68° ± 2°, which corresponds well to the orientation of the vein in the fundus image.
3 beam D-OCT enables to determine absolute velocity, flow and flow vector orientation of moving scatterers without a-priori knowledge of the orientation of the vessel. With further development volumetric and circumpapillary velocity and flow measurement of retinal blood flow and the diagnosis of ocular perfusion abnormalities may be possible.
This PDF is available to Subscribers Only