What is the specificity of vision loss in optic neuritis (inflammation of the optic nerve)?

From the Guidelines

The specificity of vision loss in optic neuritis is characterized by central or arcuate defects, as evidenced by visual field examination, with a significant proportion of patients experiencing poor visual outcome, including only 30% maintaining a visual acuity greater than 20/25 1.

Key Features of Vision Loss in Optic Neuritis

• Central vision loss with central scotoma is a common presentation
• Patients may experience a rapid decline in vision over hours to days, often accompanied by pain with eye movement
• Vision loss can range from mild blurring to severe loss of visual acuity
• Color vision is frequently affected, with patients reporting desaturated or washed-out colors, particularly red
• Visual field testing typically reveals central or cecocentral scotoma pattern

Diagnostic Considerations

• Funduscopy may reveal optic disc oedema in 30-40% of cases
• Visual-evoked potentials may detect bilateral optic nerve damage before it is clinically apparent
• Contrast-enhanced MRI showing optic nerve enhancement in 60-70% of cases supports the diagnosis
• Brain MRI abnormalities are also common, occurring in 67% of cases 1

Treatment and Prognosis

• Pulse intravenous methylprednisolone in combination with intravenous cyclophosphamide is recommended for treatment
• Relapses may occur and merit chronic immunosuppressive therapy
• Anticoagulation may be considered in antiphospholipid-positive patients not responding to immunosuppressive therapy
• The prognosis for visual recovery is generally poor, with only 30% of patients maintaining a visual acuity greater than 20/25 1

From the Research

Specificity of Vision Loss in Optic Neuritis

• The specificity of vision loss in optic neuritis is characterized by an abrupt loss of vision, which is often severe and may be bilateral in pediatric patients 2.
• Vision loss in optic neuritis is usually accompanied by other symptoms such as dense visual field loss, afferent pupillary defect (APD) in unilateral cases, and papillitis 2.
• The recovery of vision in optic neuritis is often incomplete, with some studies suggesting that treatment with corticosteroids may not significantly improve visual acuity or contrast sensitivity 3, 4.
• However, other studies have found that high-dose intravenous corticosteroids may reduce the risk of developing multiple sclerosis in patients with acute optic neuritis 5.
• The use of bioequivalent oral corticosteroids has been shown to be as effective as intravenous corticosteroids in treating acute optic neuritis, with similar improvements in visual evoked potential latency and best-corrected visual acuity 6.

Factors Influencing Vision Loss in Optic Neuritis

• The severity of vision loss in optic neuritis can vary depending on the underlying cause, with some cases being associated with multiple sclerosis or other demyelinating diseases 3, 5.
• Pediatric patients with optic neuritis may experience more severe vision loss and are at higher risk of recurrence 2.
• The presence of signal abnormalities on magnetic resonance imaging (MRI) of the brain may indicate a higher risk of developing multiple sclerosis in patients with acute optic neuritis 5.