Figure 1.
SLO fundus image of a venous junction.
Angle is determined from the slope of the tangent to the vessel at the measured location. wsl,x, wsl,y; image width in x- and y-direction. DP; detection plane.
Figure 2.
Flow chart for bidirectional Doppler FD-OCT.
Flow chart explaining velocity extraction based on bidirectional Doppler FD-OCT.
Figure 3.
Geometrical situation at the posterior pole of the eye.
and
, probe beam wave vectors;
, velocity vector;
and
, Doppler angles;
, separation angle between probe beams;
, angle between
and the plane perpendicular to the detection plane;
, change in illumination angle due to eye movement.
Table 1.
Baseline blood pressure, pulse rate and vessel diameters at the two study days.
Table 2.
Velocity, diameter and blood flow data under baseline conditions and during 100% oxygen breathing measured on Doppler OCT or Laser Doppler Velocimetry study day.
Figure 4.
Correlation analysis for velocity measurements.
Correlation between velocity and blood flow as assessed with LDV and OCT, respectively, during baseline conditions and during hyperoxia.
Figure 5.
Bland-Altman of velocity measurements.
Bland-Altman plot comparing velocity data as obtained with laser Doppler velocimetry and with bidirectional Doppler FD-OCT. Data are presented for baseline conditions as well as for conditions during systemic hyperoxia.
Figure 6.
Bland-Altman plot of blood flow calculation.
Bland-Altman plot comparing retinal blood flow data as calculated from measurements of blood flow velocity obtained either with laser Doppler velocimetry or with bidirectional Doppler FD-OCT combined with diameter measurements with the Dynamic Vessel Analyzer. Data are presented for baseline conditions as well as for conditions during systemic hyperoxia.
Figure 7.
Phase tomograms at baseline and during hyperoxia.
Sample OCT measurements as obtained in both channels during baseline conditions (A) and during breathing 100% oxygen (B). Vasoconstriction and reduction of velocity can be observed in the lower tomograms.
Figure 8.
Sample phase extraction of a baseline measurement.
Over the measurement period of 12 s the eye moved relative to the incoming laser beams resulting in pronounced changes in Ф1 and Ф2, but almost unchanged ΔФ.
Figure 9.
Sample phase extraction of a baseline measurement.
Over the measurement period of 12 s several small eye movements can be seen resulting in pronounced changes in Ф1 and Ф2, but almost unchanged ΔФ. In addition, the eye also shows a slight overall movement resulting in shifts of Ф1 and Ф2 over time.
Figure 10.
Angle as calculated from measurements using OCT (red) and LDV (blue) from the two channels. Calculations were done at baseline conditions as well as during hyperoxia.