Optical coherence tomography angiography (OCTA) has undergone tremendous growth since its first commercial introduction in 2014. Because it provides injection-free, capillary-resolution, 3-dimensional angiography of the retina and choroid, OCTA is likely to overtake fluorescein as the most important angiographic imaging technique in the eye. Nearly all manufacturers of ophthalmic OCT now offer OCTA products. A PubMed search now yields over 5700 articles on OCTA and related terms. Clinical investigators have already found a use for OCTA in almost every category of retinal and optic nerve diseases. This book is meant to bring together all this information so clinicians can have one authoritative text to turn to as we begin to use this new imaging modality that was never taught when we were in formal training.