Treatment of Optic Neuritis
High-dose intravenous methylprednisolone (1000 mg/day for 3 days) followed by oral prednisone (1 mg/kg/day for 11 days) is the recommended first-line treatment for acute optic neuritis. 1, 2
First-Line Treatment Algorithm
- Begin with intravenous methylprednisolone 1000 mg/day for 3 days 1, 2
- Follow with oral prednisone 1 mg/kg/day for 11 days 1, 2
- Treatment should be initiated promptly, as delay beyond 2 weeks is associated with poorer outcomes 1
Treatment Considerations for Specific Causes
Multiple Sclerosis-Associated Optic Neuritis
- High-dose IV methylprednisolone speeds recovery but does not improve final visual outcome 3, 4
- Early treatment with IV methylprednisolone may delay progression to clinically definite multiple sclerosis at 2 years, but this benefit diminishes after 2 years 2, 4
- For patients at high risk of developing MS (based on MRI findings), immune prophylaxis with beta-interferon or glatiramer acetate should be considered 3
Systemic Lupus Erythematosus-Associated Optic Neuritis
- Combination therapy with pulse IV methylprednisolone and IV cyclophosphamide is recommended 5, 1
- Visual outcomes are generally poorer, with only 30% maintaining visual acuity greater than 20/25 5, 1
- Maintenance immunosuppressive therapy is often needed due to high relapse rates (50-60%) during corticosteroid dose reduction 5
- For antiphospholipid-positive patients not responding to immunosuppressive therapy, anticoagulation may be considered 5, 1
Neuromyelitis Optica (NMO)-Associated Optic Neuritis
- IV methylprednisolone is the initial treatment 5
- For refractory cases, rituximab has shown better efficacy than azathioprine in reducing relapse rates 5
- Plasma exchange may be beneficial in severe cases not responding to steroids 5
Important Caveats
- Oral prednisone alone (without preceding IV methylprednisolone) is contraindicated due to increased risk of recurrence 1, 6
- The FDA warns against using oral corticosteroids alone in optic neuritis as it may increase the risk of new episodes 7
- MRI of the brain should be performed to assess risk of progression to multiple sclerosis 1, 2
- Patients with three or more lesions on MRI have a significantly higher risk of developing multiple sclerosis (rate ratio 5.53) 2
- Bioequivalent high-dose oral corticosteroids (1250 mg prednisone) may be considered as an alternative to IV administration when IV treatment is not feasible 8
Monitoring and Follow-up
- Regular ophthalmological evaluations including visual acuity, visual fields, and funduscopy are necessary to monitor treatment response 1
- Visual-evoked potentials may detect bilateral optic nerve damage before it becomes clinically apparent 5, 1
- Even with good recovery of visual acuity, contrast sensitivity, color vision, and visual field may remain impaired 6