The optic disc is shaped like a doughnut with a pink neuroretinal rim and a central white depression called the physiologic cup.Check out the color of the neuroretinal rim, which carries the axons of the retinal ganglion cells. It should be orange-pink. If its axons die, the rim will turn white.he optic disc is shaped like a doughnut with a pink neuroretinal rim and a central white depression called the physiologic cup.