Optic neuritis typically presents with acute vision loss in young females that progressively recovers. MRI of the brain and orbits with FLAIR, STIR, and post-contrast T1 sequences is critical to identify demyelinating lesions suggestive of multiple sclerosis in 50-60% of cases. Atypical features like vision loss in older males that does not recover or bilateral involvement suggest alternative diagnoses that should be considered, such as anterior ischemic optic neuropathy or neuromyelitis optica. The key imaging goal in optic neuritis is to identify signs of multiple sclerosis or other demyelinating diseases.

1. Optic neuritis
Imaging findings

2. Presentation
typically young females
acute and painful vision loss over hours or days
typically vision recovers progressively
if vision remains poor consider other diagnoses

3. 50-60% of ON cases develop multiple sclerosis subsequently
MS can present with ON in 15-25%
early immunotheraphy decreases risk of MS
 imaging the brain is critical in ON

4. if acute vision loss in older male which does not recover
and with normal MRI (in 75% of cases)
 consider anterior ischemic optic neuropathy

5. MRI protocol
axials + sagittals on the BRAIN
FLAIR
axials + coronals on the ORBIT
STIR
T1+C FS

6. typical findings
mid intraorbital optic nerve commonly involved
only minimal enlargement of optic nerve
segmental contrast enhancement of optic nerve
typically central
can be tram-track - DDX meningioma – does not present with acute vision loss

7. if bilateral ON
consider NMO or Devic’s syndrome
with transverse myelitis

8. Remember
the most important imaging task in the setting
of ON is to identify potential
demyelinating brain disease