Optic neuritis is inflammation of the optic nerve that causes vision loss over hours to days, often with pain on eye movement. It mostly affects young women and can be the first sign of multiple sclerosis.
Key symptoms
- Blurred or dim vision in one eye
- Pain behind the eye, worse when moving the eye
- Colors look faded, especially red
- Flashes of light
What you find on exam
- Reduced visual acuity and color vision
- Relative afferent pupillary defect on the swinging flashlight test
- Visual field defect, often central
- Optic disc normal or swollen on fundoscopy
Tests
- MRI of the brain and orbits with contrast
- AQP4 and MOG antibody tests in atypical cases
- Inflammatory and infection tests if the picture is atypical
Treatment basics
- IV methylprednisolone for 3 to 5 days to speed recovery
- Avoid low-dose oral prednisone alone, which raises recurrence
- Neurology referral for MS risk and disease-modifying therapy
- Most patients recover much of their vision over weeks
Red flags
- Both eyes affected or very severe vision loss
- No improvement after 2 to 3 weeks
- Age over 50 with headache or jaw pain when chewing (possible giant cell arteritis)
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations. Written by Making Synapses. Making Synapses is not affiliated with these organizations.