Optic atrophy is pallor of the optic nerve head as visualized by ophthalmoscopy. The temporal disc may appear pale in a normal fundus, so that optic atrophy can only be confidently diagnosed when there is also nasal pallor, although temporal pallor may follow damage to the macular fibre bundle with central visual defects.
Optic atrophy may be the consequence of any optic neuropathy which causes optic nerve damage leading to gliotic change of the optic nerve head. The appearance of optic atrophy is nonspecific with respect to etiology. Common causes include previous optic neuritis and chronic papilledema, but retinal lesions, optic chiasm and optic tract pathologies can all produce optic atrophy (e.g., inherited optic neuropathies, tobacco-alcohol amblyopia; vitamin B12 deficiency).
"Hemianopic" optic atrophy, indicates involvement of the optic tract
or lateral geniculate body.