optic atrophy, wasting of the optic disc resulting from degeneration of fibers of the optic nerve and optic tract. In primary optic atrophy the disc is white and sharply margined, the central depression (physiological cup) is enlarged, and the optic foramen of the sclera is clearly visible. In secondary atrophy the disc is gray, its margins are blurred, the depression is filled in, and the foramen is difficult to detect. Optic atrophy may be caused by a congenital defect, inflammation, occlusion of the central retinal artery or internal carotid artery, alcohol, arsenic, lead, tobacco, or other toxic substances. Degeneration of the disc may also accompany arteriosclerosis, diabetes, glaucoma, hydrocephalus, pernicious anemia, and various neurological disorders.
