Abstract: Optical coherence tomography angiography (OCTA) uses flowing blood cells as intrinsic motion contrast to produce depth-resolved images of blood flow in a rapid non-invasive fashion. Its limitations include limited field of view, unable to show vessel wall infiltration and leakage, imaging artifacts, and poor agreement of OCTA measurements among different devices. It is critical to recognize the artifacts while interpreting OCTA images. OCTA improved our understanding and clinical management of retinal diseases. OCTA is able to detect microvascular changes in diabetic patients before clinical retinopathy is detectable and quantify capillary dropout in different retinal plexus, which is significantly associated with visual prognosis and treatment requirement. OCTA can sensitively detect clinically unsuspected retinal neovascularization that is missed by experienced retinal specialist in diabetic patients.  OCTA measured retinal neovascularization area is useful in monitoring treatment reaction in diabetic patients. For the first time, OCTA enable us to detect non-exudative choroidal neovascularization in vivo in patients with age-related macular degeneration. OCTA quantified choriocapillaris defect is significantly associated with the development and progression of geographic atrophy. （Ophthalmol CHN, 2022, 31: 81-88）

Key words:  , optical coherence tomography angiography, diabetic retinopathy, age-related macular degeneration