Synopsis
Recognise inflammatory optic-nerve dysfunction, distinguish typical demyelinating disease from urgent atypical causes, and coordinate ophthalmic assessment, neurological investigation and appropriately selected treatment.
- Typical optic neuritis produces subacute visual reduction, impaired colour or contrast perception and pain that often increases with eye movement.
- A relative afferent pupillary defect supports unilateral or asymmetric optic-nerve dysfunction, but its absence does not exclude symmetric bilateral disease.
- The optic disc can look normal when inflammation lies behind the globe; a normal fundus does not establish normal optic-nerve function.
Key red flags
Severe bilateral loss, marked disc swelling, unusual neurological findings or poor early recovery requires urgent assessment for an atypical inflammatory or other optic neuropathy.
Investigation priorities
Document the pattern and baseline severity of optic dysfunction.
Management branches
A patient develops new visual loss with a possible optic-nerve pattern.
- Measure vision and pupils, ask about movement-related pain and neurological symptoms, and arrange urgent ophthalmic examination.
- Check for retinal, corneal, vascular or compressive alternatives, including giant-cell arteritis when age and symptoms make it plausible.
Key medicines
Methylprednisolone for a confirmed MS relapseNICE recommends oral methylprednisolone 500 mg once daily for five days when an MS relapse is selected for treatment. Intravenous methylprednisolone 1 g daily for three to five days is an alternative when oral treatment fails or is not tolerated, or admission is needed for severity or monitoring.