In vivo imaging of human retinal flow dynamics by color Doppler optical coherence tomography.

BACKGROUND Color Doppler optical coherence tomography (CDOCT) combines laser Doppler velocimetry and optical coherence tomography for simultaneous micron-scale resolution cross-sectional imaging of tissue microstructure and blood flow. Recently, CDOCT was adapted to a slitlamp biomicroscope for imaging structure and blood flow in the human retina. OBJECTIVE To demonstrate feasibility of CDOCT for imaging retinal hemodynamics. DESIGN Enabling CDOCT to measure retinal blood flow pulsatility in humans. SETTING Laboratory. MAIN OUTCOME MEASURES Time-resolved flow profiles and images of retinal blood flow dynamics for measurement of pulsatility within retinal vessels. RESULTS Rapid sequences of images were acquired over selected vessels near the optic nerve head. From these images, retinal blood flow profiles were extracted and synchronized to an external reference obtained with a photoplethysmograph. Each profile was acquired in less than 10 milliseconds. CONCLUSIONS Our results indicate that CDOCT provides laser Doppler information in addition to conventional optical coherence tomography, allowing the observation of blood flow dynamics simultaneous to imaging retinal structure. CDOCT is a promising technology for research and clinical studies of retinal blood flow dynamics. CLINICAL RELEVANCE Blood flow dynamics, such as pulsatility and autoregulation, have been shown to change throughout the progression of diabetic retinopathy and glaucoma. Enabling CDOCT to observe retinal dynamics improves its potential as a clinical diagnostic tool.