Pathophysiology
Optic neuritis is the inflammation of the optic nerve, causing damage to it. It occurs due T-cells that cross the BBB → hypersensitivity to neuronal structures. It occurs mostly in adult women in the northern hemisphere.
It occurs due to:
- Multiple sclerosis and other demyelinating disorders - the most common cause. Optic neuritis is one of the early presentations of multiple sclerosis in about 20-30% of patients. If there are >3 white-matter lesions on an MRI brain then there is a 50% likelihood of developing MS within 5 years.
- Diabetes mellitus
- Syphilis
😷 Presentation
It commonly presents in females (20-40 years old).
They present with:
- Decrease in visual acuity over hours or days.
- Red desaturation
- Painful eye - worse upon movement.
- Relative afferent pupillary defect
- Central scotoma
🔍 Investigations
🏆 Fundoscopy - shows normal or swollen optic disk. There may be optic atrophy and disc pallor present later on due to atrophy of the nerve fibres and small vessels.
An MRI of the brain and orbits with gadolinium contrast would also be done to assess for MS and of course optic nerve inflammation.
🧰 Management
- High-dose steroids - resolves in 4-6 weeks usually.
