Optical Coherence Tomography Angiography in Retinal Vascular Diseases and Choroidal Neovascularization

Abstract

Purpose. To assess the ability of optical coherence tomography-angiography (OCT-A) to show and analyze retinal vascular patterns and the choroidal neovascularization (CNV) in retinal vascular diseases. Methods. Seven eyes of seven consecutive patients with retinal vascular diseases were examined. Two healthy subjects served as controls. All eyes were scanned with the SD-OCT XR Avanti (Optovue Inc, Fremont CA, USA). Split spectrum amplitude decorrelation angiography algorithm was used to identify the blood flow within the tissue. Fluorescein angiography (FA) and indocyanine green angiography (ICGA) with Spectralis HRA + OCT (Heidelberg Engineering GmbH) were performed. Results. In healthy subjects OCT-A visualized major macular vessels and detailed capillary networks around the foveal avascular zone. Patients were affected with myopic CNV (2 eyes), age-related macular degeneration related (2), branch retinal vein occlusion (BRVO) (2), and branch retinal artery occlusion (BRAO) (1). OCT-A images provided distinct vascular patterns, distinguishing perfused and nonperfused areas in BRVO and BRAO and recognizing the presence, location, and size of CNV. Conclusions. OCT-A provides detailed images of retinal vascular plexuses and quantitative data of pathologic structures. Further studies are warranted to define the role of OCT-A in the assessment of retinovascular diseases, with respect to conventional FA and ICG-A.

Correlation between Basal Macular Circulation and Following Glaucomatous Damage in Progressed High-Tension and Normal-Tension Glaucoma

“…The basic mechanism of OCTA is split-spectrum amplitude-decorrelation angiography, which analyzes blood flow and demonstrates the volume and distribution of retinal and choroid vasculature [3]. Unlike conventional angiography with a contrast agent, such as fluorescein angiography or indocyanine green angiography, OCTA prevents the possibility of wound infection and allergic reactions due to its non-invasive nature without the intravenous puncture procedure and contrast agent injection [4].…”

Optical Coherence Tomography Angiography – A General View

“…[1][2][3] OCTA is a good method for imaging the microvasculature in the diseases that affect the central macula, including age-related macular degeneration (AMD), diabetic maculopathy, retinal vascular occlusion, macular telangiectasia type 2 and the microvasculature in optic nerve diseases. [4][5][6][7][8][9][10][11] Additionally, using OCTA, features of some disorders, including polypoidal choroidal vasculopathy (PCV), paracentral acute middle maculopathy, central serous chorioretinopathy and sickle cell retinopathy have been reported. [12][13][14][15] The aim of this review is to provide some general information about OCTA, including the algorithms used, commercial/uncommercial devices and their specifications, and the advantages and disadvantages of OCTA for retinal and choroidal vascular imaging.…”

“…The imaging of choriocapillaris, and the neovascular vessels at avascular outer or deep retina mapping using the segmentation algorithm might be more important, especially in cases of early or intermediate AMD or PCV to detect core vessels. [1][2][3][4][5][6][7][8][9][10][11] OCTA can penetrate retinal haemorrhage, depending on the density of the haemorrhage. OCTA can also identify the retinal ischaemic areas through the high contrast between vessels and the surrounding retina.…”

“…[3][4][5][6][7][8][9][10][11] Because OCTA can image the separate retinal layers, it can be used to easily visualise choroidal neovascularization (CNV). 3,[30][31][32][33] In a healthy eye, there is an avascular retinal region in the deep or outer layer of the retina.…”

Advances in Optical Coherence Tomography Angiography

“…OCTA is a non-invasive, non-dye-based imaging technique that employs motion contrast to create high-resolution depth-resolved angiographic images of vascular flow in a matter of minutes. [1][2][3] The software compares the decorrelation signal or phase variance between consecutive OCT B-scans acquired at the same retinal cross-section to detect motion contrast. [4][5][6] Multiple OCTA image artifacts may affect image quality.…”