Optic neuritis as an early sign of multiple sclerosis.

Optic neuritis (ON) is an acute inflammatory demyelinating disorder of the optic nerve. The general characteristics of isolated ON include unilateral, subacute, and painful visual loss without systemic or other neurological symptoms. The etiology for ON varies including demyelinating disorders or infections, inflammation, toxic reasons, and genetic disorders. In most cases the responsible etiology may not be known for ON and in this case, it is termed idiopathic ON. When a patient presents with an initial episode of ON, patients should undergo further tests. Assessing the patient with routine blood work, magnetic resonance imaging, cerebrospinal fluid tests, and visual evoked potentials provide further insight. In this review, we aimed to provide a review of ON as an initial symptom of multiple sclerosis and present clinical characteristics, therapy options, and recent literature.