1A. A full-thickness retinal slab was selected by selecting the ILM and RPE as boundaries. The boundaries were not changed for the measurements in the disc area, and the instrument automatically connected the two ends of the RPE as outer boundary. Vessel intensity ratios from 3 regions of interest were calculated, 1B. Papillary region (3 mm circular region centered on the ONH), 1C. Peripapillary region (700 micron wide elliptical annulus centered on the disc), 1D. The optic nerve head