Fig. 1

Measurement of the intradisc vessel density (dVD). (A) Color disc image. (B) En-face whole signal mode optic nerve head (ONH) optical coherence tomography angiography (OCTA) image. (C) Same image as (B) with the disc margin demarcated by the red line. (D) En-face OCTA image of ONH, converted to binary format. The dVD was calculated as the percentage of the white vascular area within the optic disc. (E) Same image as (D) with the ONH area divided into four sectors (superior, temporal, inferior, and nasal) according to a 90° range around the ONH center. Since disc hemorrhage (DH) was observed in the inferior qudarant (red arrow, A), the dVD of the inferior quadrant was considered as the dVD in the DH-affected quadrant (wedge shape demarcated with red line and accompanied by a red arrow, E).