The cause of ONA is dependent upon the type of atrophy present:

• Demyelinating ONA, also known as optic neuritis, occurs in conditions such as multiple sclerosis and other demyelinating and inflammatory conditions. Patients often present with rapid loss of vision in one eye, which may be loss in part or all of the visual field.
• Ischemic ONA results from occlusion of blood vessels supplying the optic nerve and can occur in conditions such as vasculitis, giant cell arteritis, granulomatosis with polyangiitis, and rheumatoid arthritis. Patients with ischemic ONA develop rapidly progressing loss of vision, often in the superior aspect of their visual field.
• Traumatic ONA results from direct injury to the optic nerve, often from blunt force or accidents such as motor vehicle collisions.
• Inflammatory ONA, also known as infiltrative neuropathy, results in the destruction of the optic nerve from locally invading tumors, infection, and autoimmune processes such as sarcoidosis.