In this submission we demonstrate a new application of the joint Spectral and Time domain Optical Coherence Tomography (STdOCT) technique for segmenting and measuring the retinal blood flow velocity in three dimensions. The method is based on direct detection of Doppler shift that arises in time during the measurement. New scanning protocols and analysis tools are proposed to create velocity distribution maps of the retina and to segment and visualize 3D vasculature of human eye in-vivo. STdOCT segmentation is more sensitive than methods based on phase measurements and calculations are more straightforward than other techniques, which require more complex experimental setup and more sophisticated numerical tools. The usage of ultra-fast line scan camera allows to broaden the axial velocity range up to +/-24mm/s, thus all high flows in human retina can be registered.