Nomenclature and Current Indications of Optical Coherence Tomography Angiography in Diseases of the Choroid and Retina

Abstract

One of the most significant developments in ocular imaging in the last century was optical coherence tomography (OCT). OCT angiography (OCT-A), an extension of OCT technology, offers depth-resolved images of the blood flow in the choroid-retina that are much more detailed than those produced by earlier imaging techniques such as fluorescein angiography (FA). Due to its requirements of novel tools and processing methods, the prevailing imaging constraints, the rapid improvements in imaging technology, and our knowledge of the imaging and relevant pathology of the retina and choroid, this novel modality has been challenging to implement in daily clinical practice. Even those familiar with dye-based ocular angiography will find that mastering OCT-A technology requires a steep learning curve due to these issues. Potential applications of OCT-A include almost all diseases of the choroid and retina, as well as anterior segment diseases. Currently, the most common indications are age-related macular degeneration and ischemic retinopathies, including diabetic retinopathy and retinal occlusive vascular disorders. Incorporating OCT-A into multimodal imaging for the comprehensive assessment of retinal pathology is a fast-growing area, and it has expanded our knowledge of these complex diseases in terms of diagnosis and treatment. This review describes the current main indications of OCT-A in retinal and choroidal diseases.