In OCTA, resolution of retinal capillaries is limited by physical numerical aperture of human eye and the subject’s ocular aberrations. Adaptive optics OCTA has been demonstrated in instruments with large numerical aperture, originally designed for the visualization of retinal cells. In this work, we propose a high-speed, spectral domain sensorless adaptive optics OCTA instrument with a 3-mm beam to image retinal capillaries of all three retinal plexuses simultaneously, with high axial and lateral resolution. A novel and fast hill climbing algorithm was applied on the amplitude of six low-order Zernike modes to minimize ocular aberrations based on maximizing en face merit functions of the layer of interest computed in real time.