OCT-Angiography (OCTA) is a new technology for visualising ocular blood flow by identifying retinal microcirculation using the motion of blood cells in the vessels to show the microvasculature with unprecedented detail.
Unlike conventional intravenous fluorescein angiography and indocyanine green angiography, OCTA requires no dye injection to examine the circulation of the retina and choroid. Instead, it generates high-resolution vascular imaging by using the intrinsic motion of blood cells within vessels as contrast medium, and separates motion from within blood vessels from static background outside these vessels.
The Avanti XR, OptoVue’s wide-field OCT, is currently the only commercially available system equipped with an optional OCTA feature. With the Angio Flow feature, scan sizes up to 8 mm × 8 mm are acquired in a few seconds for visualisation of retinal and choroidal microvasculature at superficial capillary, deep capillary, outer retina and choroidal capillary levels. Image enhancement uses Split-Spectrum Amplitude Decorrelation Algorithm and Motion Correction Technology.
OCT Angiography imaging is three-dimensional. En face scans can be viewed at any depth within the OCT cube scan and are typically parallel to Bruch’s membrane or the retinal pigment epithelium.
|AngioFlow of macula