Optical Coherence Tomography Angiography

Optical coherence tomography angiography (OCTA) is a new revolutionary non-invasive imaging modality, built on the platform of optical coherence tomography (OCT). This technique works on the principle of ‘decorrelation’ and is still a nascent technology in its infancy with tremendous potential applicability for diagnosing retinal and choroidal vascular diseases. Its non-invasive nature, and the ability to generate images of retinal and choroidal vasculature, allows it to replace and/or supplement the current angiographic gold standards, fluorescein angiography (FA) and indocyanine green angiography (ICGA), if not in all but certainly in most retinal and choroidal pathologies. Still, there exists a major challenge in terms of its wide-scale availability, equipment and processing techniques, presence of artifacts, limitations of imaging capability, and lack of common vocabulary among retinal specialists for interpretation. In this review we intend to describe this novel technique by highlighting its key features, and comparing it with FA and ICGA. We will also discuss its applicability in various clinical scenarios such as diabetic retinopathy, age-related macular degeneration, retinal venous occlusion, choroiditis, and in routine practice. Further studies are needed to more definitively determine OCTA’s utility in the clinical setting and to establish if this technology may offer a non-invasive option of visualizing the retinal vasculature in detail.