Retinal nonperfusion (NP) is a biomarker for assessment of the severity of diabetic retinopathy and retinal vein occlusion. However, various conditions mimic the retinal NP flow void signals that are observed in optical coherence tomography angiography (OCTA).
In this review, the possible mechanisms for these similar void flow signals in OCTA were summarized, and the discrepancies between the evaluations of retinal NP with fluorescein angiography and OCTA were also investigated and evaluated in terms of size and morphology.
Vascular occlusion, resulting in retinal ischemia, leads to a flow void signal, indicating retinal NP in OCTA images. In addition, displacement of retinal vessels secondary to cystoid macular edema presents a false NP signal and produces a flow void signal similar to that of retinal NP in OCTA. Finally, various pathological conditions can coexist in the same retinal disease, with one of these factors playing a major role. Understanding the various causes of retinal NP in OCTA will be beneficial in conducting appropriate pathological investigations and making appropriate treatment and management choices.

Copyright © 2021. Published by Elsevier B.V.

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