Fig. 1

Montaged 20 × 20°OCTA images of the central foveal region and paired arterioles and venules in the superficial vascular plexus of a 60-year-old cognitively unimpaired low-risk female. a Raw montaged OCTA image before image processing. b Vesselness filtered image in MATLAB. c Vesselness filtered and Otsu thresholded image in MATLAB. Red “A” and blue “V” represent paired arterioles and venules, respectively. Periarteriole CFZ can be seen as dark gaps around the arteriole (red “A”) while the perivenule CFZ can be seen as dark gaps around the venule (blue “V”). Periarteriole CFZ can be seen as larger than the perivenule CFZ