Fig. 1.

The framework of optical coherence tomography angiography (OCTA) image post-processing. a, b Raw images were extracted from the OCTA machines. c, d The images were binarized to obtain the large vessel densities. e An annulus centered at FAZ center with inner diameter of 1 mm and outer diameter 2.5 mm was generated as a mask to the 3 × 3 mm image. f Larger vessels were automatically detected in the superficial capillary plexus. g, h The FAZs were manually delineated from both plexuses. i, j The vessel densities were calculated in the annulus