What is the initial treatment for optic neuritis?

Initial Treatment for Optic Neuritis

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

Diagnostic Approach

• MRI of both the orbits and brain with contrast is essential for initial assessment of suspected optic neuritis to evaluate optic nerve enhancement and to check for intracranial demyelinating lesions 2
• Visual-evoked potentials may detect bilateral optic nerve damage before it becomes clinically apparent 2, 1
• Funduscopy may reveal optic disc edema (present in 30-40% of cases) and visual field examination may show central or arcuate defects 2

Treatment Protocol

• First-line treatment: Intravenous methylprednisolone 1000 mg/day for 3 days 1, 3
• Follow-up therapy: Oral prednisone (1 mg/kg/day) for 11 days with a short taper 3, 4
• Treatment should be initiated promptly, as delay beyond 2 weeks is associated with poorer outcomes 2, 1

Important Considerations

• Oral prednisone alone (without preceding IV methylprednisolone) is not recommended as it has been associated with a higher rate of new episodes of optic neuritis compared to placebo 3, 4
• Intravenous methylprednisolone speeds recovery of visual function but does not significantly improve final visual outcome at one year 3, 4
• Regular ophthalmological evaluations including visual acuity, visual fields, and funduscopy are necessary to monitor treatment response 1

Special Populations

• For optic neuritis associated with systemic lupus erythematosus (SLE), pulse intravenous methylprednisolone should be combined with intravenous cyclophosphamide 2, 1
• In pediatric optic neuritis, intravenous methylprednisolone (4-30 mg/kg per day) for 3-5 days followed by a prolonged oral corticosteroid taper (2-4 weeks) is recommended to avoid recurrence 5

Second-Line Treatments

• For refractory cases or patients not responding to first-line therapy, options include:
  • Plasma exchange therapy for severe cases 2, 1
  • Rituximab, particularly in cases associated with neuromyelitis optica spectrum disorder 1, 6
  • Anticoagulation may be considered in antiphospholipid-positive patients not responding to immunosuppressive therapy 2, 1

Risk Factors for Poor Outcomes

• Delay in treatment initiation (>2 weeks) 2, 1
• Presence of antiphospholipid antibodies 2
• In SLE-related optic neuritis, only 30% of patients maintain visual acuity greater than 20/25 2, 1
• Relapses are common (50-60%) during corticosteroid dose reduction, highlighting the need for maintenance immunosuppressive therapy in some cases 2, 1