Optic neuritis describes any condition that causes inflammation of the optic nerve; it may be associated with demyelinating diseases, or infectious or inflammatory processes. It is also known as optic papillitis (when the head of the optic nerve is involved), neuroretinitis when there is a combined involvement of optic disc and surrounding retina in the macular area and retrobulbar neuritis (when the posterior part of the nerve is involved). It is most often associated with multiple sclerosis, and it may lead to complete or partial loss of vision in one or both eyes. Other causes include:Idiopathic (cause is unidentifiable) Hereditary optic neuritis (Leber's disease) Parainfectious optic neuritis (associated with viral infections such as measles, mumps, chickenpox, whooping cough and glandular fever) Infectious optic neuritis (sinus related or associated with cat scratch fever, tuberculosis, lyme disease and cryptococcal meningitis in AIDS patients Autoimmune causes (sarcoidosis, systemic lupus erythematosus, PAN, granulomatosis with polyangiitis)
Partial, transient vision loss (lasting less than one hour) can be an indication of early onset multiple sclerosis. Other possible diagnoses include diabetes mellitus, low phosphorus levels, or hyperkalaemia.
Chronic alcohol abuse may produce problems in the optic nerve, called alcoholic optic neuritis. The main causes are vitamin B1 deficiency, and in some cases, zinc deficiency or raised lead levels.