Flicker-induced changes in retinal blood flow assessed by Doppler optical coherence tomography

We used Doppler Fourier-domain optical coherence tomography (OCT) to investigate flicker-induced changes of total retinal blood flow. Total retinal blood flow was measured by summing flows in veins imaged in double-circular scans around the optic disc. In 3 healthy volunteers, total retinal blood flow was measured before and 10-15 seconds after 30 seconds of flicker stimulation. The average blood flow increased 22.2% (p = 0.002). The total venous and arterial vessel cross-sectional area increased 11.3% (p < 0.001) and +2.7% (p = 0.28) respectively. The average venous and arterial flow velocity were calculated indirectly by dividing total retinal blood flow by total venous and arterial cross-sectional areas. They also increased by 8.8% (p = 0.046) and 18.3% (p = 0.004), respectively. These results show that human retinal blood flow increases after visible flicker stimulation, and this could be measured with OCT.