Dark Signals in the Choroidal Vasculature on Optical Coherence Tomography Angiography: An Artefact or Not?

Figure 5

Polypoidal choroidal vasculopathy on OCTA. The round hypoflow appearance of the polyps on OCTA is probably due to unusual blood flow inside the polypoidal lesion (red arrows) in contrast with that in the branching vascular network. This indicates that blood flow is not within the detection limit of the OCTA device (yellow dash-dots on indocyanine green angiography show the range of OCTA; SD-OCT shows both RPE detachment and a double-layer sign; the left side shows anonymised patient information). ICGA: indocyanine green angiography; OCTA: optical coherence tomography angiography; RPE: retinal pigment epithelium; SD-OCT: spectral-domain optical coherence tomography.