An Approach to Measure Blood Flow in Single Choroidal Vessel Using Doppler Optical Coherence Tomography

PURPOSE: To evaluate the absolute blood flow rate in a single choroidal vessel using Doppler optical coherence tomography (OCT). METHODS: Three choroidal vessels were selected in the right eye of three normal subjects, and were measured with Doppler OCT at a 1020-nm probe wavelength. The pulsatile change of the blood flow was obtained from synchronized measurement of Doppler OCT and plethysmography. Absolute blood flow rates in choroidal vessels were calculated from Doppler OCT volume data. RESULTS: The cyclic change of the blood flow was quantitatively obtained. Absolute blood flow velocities and blood flow rates at peak systole [mean (SD)] were 46.9 (12.5) mm/s and 5.9 (3.6) μL/min, respectively. The coefficient of variation of three sets of measurements [mean (SD)] was 9.3 (4.9%). CONCLUSIONS: Doppler OCT and plethysmography provided an accurate quantitative assessment of the blood flow in choroidal vessels. This measurement technique could prove valuable to the study of choroidal blood flow in normal and pathologic conditions.