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Optic neuritis
Typical optic neuritis is vision loss in one eye over days with pain on eye movement, reduced colour vision and a relative afferent pupillary defect, which mostly recovers on its own — and its importance is as a marker of multiple sclerosis risk.
Why it matters in the exam
The classic scenario is a young woman with pain on moving the eye, blurred vision and "washed-out" red. The tests check the findings (relative afferent pupillary defect, central scotoma, a disc that looks normal in most cases), the treatment (intravenous methylprednisolone speeds recovery but does not change the final outcome, while standard-dose oral prednisone alone increased recurrence), and the role of brain MRI in estimating MS risk. Another part is telling typical neuritis from other conditions: anterior ischaemic optic neuropathy (NAION) in an older painless patient, giant cell arteritis, and atypical neuritis that suggests NMOSD or MOGAD. Visual field testing usually shows a central scotoma, and some patients describe flashes of light on eye movement.
Key points
- Typical neuritis: a young woman, pain on eye movement, reduced colour vision and a relative afferent pupillary defect.
- The disc is normal in about two thirds of cases (retrobulbar neuritis).
- Intravenous methylprednisolone speeds recovery but does not change the final outcome.
- Lesions on brain MRI greatly raise the risk of multiple sclerosis.
- Bilateral, severe or not improving — suspect NMOSD, MOGAD or another cause.
Summary table
| Feature | Typical | Atypical — suspect something else |
|---|---|---|
| Age and sex | Women aged 20 to 45 | A child, an older adult, or an older man with vascular risk factors (NAION) |
| Pain | Pain on eye movement in most cases | No pain (NAION, hereditary) or very severe pain |
| Vision and exam | Loss over days, poor colour vision, relative afferent pupillary defect, normal disc in about two thirds | Bilateral, very severe loss, disc swelling with haemorrhages, loss of the upper or lower half of the field |
| Course | Improvement beginning within 3 weeks | No improvement or worsening — test AQP4 and MOG, ESR in older adults |
| Treatment | Methylprednisolone 1 g intravenously daily for 3 days, then oral prednisone — speeds recovery | Standard-dose oral prednisone alone is not recommended; NMOSD — plasma exchange |
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Sources
- Optic Neuritis Treatment Trial (ONTT, NEJM), 1992 — Corticosteroid treatment arms and outcomes
- Diagnosis and Classification of Optic Neuritis (Petzold et al., Lancet Neurology), 2022 — Typical and atypical features
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.