Clinical Implications of Alternating Hypointense Bands on OCT Angiography in Retinal Vascular Occlusive Disease

Abstract

PurposeTo demonstrate the relationship between alternating hypointense signal bands on optical coherence tomography-angiography (OCTA), real-time fluorescein angiography (FA), and structural OCT findings in patients with retinal vascular occlusive disease (RVOD). DesignRetrospective, consecutive case series. SubjectsConsecutive patients with a clinical diagnosis of acute RVOD and alternating bands of hypointense OCTA flow signal on en face projections. MethodsComplete ophthalmic examination and multimodal imaging, including color fundus photography (CFP), real-time FA, SD-OCT, and OCTA performed with different instruments having different scan speeds and acquisition protocols. Main Outcome MeasurementsThe primary outcomes were: Hypointense OCTA band characteristics (number, width, orientation, and location), OCTA acquisition characteristics (speed and scan direction), and FA findings including delayed arteriovenous (AV) transit and pulsatile flow. Secondary outcomes were: Structural OCT changes including retinal fluid, paracentral acute maculopathy lesion (PAMM), and a prominent middle limiting membrane (p-MLM) sign. ResultsOCTA-hypointense bands were detected in the superficial and deep vascular plexuses in 9 eyes of 9 patients with either partial CRAO or nonischemic RVO. When obtained on the same device, hypointense bands were thinner and more numerous at lower (100 kHz) scan speeds compared with higher (200 kHz) scan speeds. Band orientation was parallel to the OCTA scan direction, and their extent correlated with the area of delayed AV transit on FA. Structural OCT showed multiple PAMM lesions in 78% of cases and a p-MLM sign centered in the fovea in 44% of cases. ConclusionsOCTA-hypointense bands are a novel biomarker in RVOD indicating delayed AV transit and pulsatile filling without the need for dye angiography. Structural OCT often shows PAMM in these eyes, and less commonly, a p-MLM sign.