What is the recommended treatment for acute optic neuritis?

Treatment of Acute Optic Neuritis

High-dose intravenous methylprednisolone is the recommended first-line treatment for acute optic neuritis, administered at 1000 mg/day for 3 days, followed by oral prednisone (1 mg/kg/day) for 11 days. 1

First-Line Treatment Protocol

• Intravenous methylprednisolone should be administered at doses of 30 mg/kg up to 1000 mg/day for 3 days to improve visual outcomes in patients with optic neuritis 1
• This should be followed by oral prednisone (1 mg/kg/day) for 11 days with a short taper 2
• Treatment should be initiated promptly, as delay beyond 2 weeks is associated with poorer outcomes 1
• MRI of the brain and orbits with contrast is essential for diagnosis and to evaluate risk for multiple sclerosis development 1

Benefits and Limitations of Treatment

• High-dose intravenous corticosteroids hasten visual recovery but do not significantly affect final visual outcome at 6 months 3
• Intravenous methylprednisolone followed by oral prednisone may provide slightly better visual fields, contrast sensitivity, and color vision at 6 months compared to placebo 2
• The treatment may delay progression to clinically definite multiple sclerosis at 2 years, but this benefit is not maintained at 5 or 10 years 3

Important Cautions

• Oral prednisone alone (1 mg/kg/day) without prior intravenous methylprednisolone should be avoided as it increases the risk of new episodes of optic neuritis 2, 4
• Regular ophthalmological evaluations including visual acuity, visual fields, and funduscopy are necessary to monitor treatment response 1
• Visual-evoked potentials may help detect bilateral optic nerve damage before it becomes clinically apparent 1

Alternative Administration Routes

• Bioequivalent oral corticosteroids (1250 mg prednisone) may be considered as an alternative to intravenous administration, as studies show no significant difference in visual recovery between the two routes 5
• This option may be more cost-efficient and convenient for patients while providing similar efficacy 5

Treatment for Special Populations

• For optic neuritis associated with systemic lupus erythematosus, pulse intravenous methylprednisolone combined with intravenous cyclophosphamide is recommended 1
• In neuromyelitis optica (NMO)-associated optic neuritis, intravenous methylprednisolone is the initial treatment, with rituximab showing better efficacy than azathioprine for refractory cases 1, 6
• Plasma exchange should be considered for severe cases not responding to steroids, particularly in NMO-associated optic neuritis 1, 6

Second-Line Treatments for Refractory Cases

• For cases not responding to first-line therapy, options include:
  • Rituximab (RTX), which has shown superior efficacy in reducing relapse rates compared to other immunosuppressants 1, 6
  • Azathioprine (AZA) at 2-3 mg/kg/day as a steroid-sparing agent 6
  • Plasma exchange (PLEX) for severe cases 1, 6
  • Mycophenolate mofetil (1-3 g/day) for maintenance therapy 6

Monitoring and Follow-up

• Patients should be monitored for development of multiple sclerosis, as optic neuritis may be the first manifestation 1
• Relapses are common (50-60%) during corticosteroid dose reduction, highlighting the need for maintenance immunosuppressive therapy in some cases 1
• Regular ophthalmological evaluations are essential to monitor treatment response 1