optic neuritis
Pronunciation: OP-tic neuro-RYE-tis
Inflammatory demyelination of the optic nerve, often the presenting symptom of multiple sclerosis.
Full Definition
Optic neuritis is an inflammatory condition affecting the optic nerve, characterized by demyelination and axonal damage that results in acute visual loss, eye pain, and visual field defects. In neuroimmunology, optic neuritis serves as a common presenting symptom of multiple sclerosis, occurring in approximately 20% of patients as their initial manifestation. The condition can also occur in isolation or as part of other demyelinating diseases such as neuromyelitis optica spectrum disorder or MOG antibody-associated disease. Diagnosis is supported by characteristic clinical features, visual evoked potentials showing delayed conduction, and MRI evidence of optic nerve enhancement or T2 hyperintensity. The inflammatory process typically involves both cellular and humoral immune responses, with potential for both spontaneous recovery and residual visual dysfunction depending on the severity and underlying etiology.
Usage
Usage note: Specify unilateral vs. bilateral involvement and document associated visual symptoms in clinical notes.
In Context
- "The patient presented with acute optic neuritis characterized by painful visual loss and relative afferent pupillary defect." — Clinical examination
- "MRI revealed enhancement of the left optic nerve consistent with acute optic neuritis." — Radiology report