Fig. 1

Representative cases with optical coherence tomography angiography images corresponding to the severity of sudden sensorineural hearing loss. The leftmost column shows baseline optical coherence tomography angiography (OCTA) images of a patient with stage 1 sudden sensorineural hearing loss (SSNHL). The middle column represents OCTA images of patients with stage 3 SSNHL, and the rightmost column shows OCTA images of patients with stage 5 SSNHL. (A–C) The first row represents superficial capillary plexus images in OCTA (D–F), while the second row denotes deep capillary plexus (DCP) images in OCTA. (G–I) Using these two images, it is possible to extract a binarized DCP image and calculate the DCP vascular density (VD) in the third row. As the severity of SSNHL worsens, the DCP VD decreases. (J–L) The parafoveal temporal regions (red dashed rectangles) with the foveal avascular zone (FAZ) of the DCP images are schematically depicted in the bottom row. At lower severity, the void spaces (red arrows) were scattered within the DCP. As the severity increased, the void spaces increased and contributed to the decreased DCP VD.