Optical coherence tomography angiography

Optical coherence tomography angiography (OCTA)^[1][2][3][4] is a non-invasive imaging technique based on optical coherence tomography (OCT) developed to visualize vascular networks in the human retina,^{[4][5][6][7][8][9]} choroid,^{[10][11][12][13]} skin^[14] and various animal models.^[15][16][17] OCTA may make use of speckle variance optical coherence tomography.

OCTA uses motion contrast between cross-sectional OCT scans (B-frames) to differentiate blood flow from static tissue, enabling imaging of vascular anatomy.^[4][18] To correct for patient movement during scanning, bulk tissue changes in the axial direction are eliminated, ensuring that all detected changes are due to red blood cell movement.^[18] This form of OCT requires a very high sampling density in order to achieve the resolution needed to detect the tiny capillaries found in the retina.^[18][19] This has allowed OCTA to obtain detailed images of retinal vasculature in the human retina^[20] and become widely used clinically to diagnose a variety of eye diseases, such as age related macular degeneration (AMD),^[21] diabetic retinopathy (DR),^[22][23] artery and vein occlusions, and glaucoma.^[24][18]