Fig. 2

Optical coherence tomography (OCT) images: showing affected optic disc (a) exhibits sharp insertion of nerve fiber at the nasal region, and the cup is deep and narrow compare to the normal control (b). The shape of the optic cup is outlined with a cone (in red). The diameter (x, in green) at the bottom of the cone represents the opening size of the optic cup, and the height (y, in blue) of the cone represents the depth of the cup. The smaller the x value is, and the larger the y value is, which means that the optic disc is narrower and deeper