Inflammatory Optic Neuropathy (Optic Neuritis)
It is caused by a number of underlying conditions:
- Systemic infection.
- Vaccination.
- Autoimmune disease.
The most commonly associated cause of inflammatory optic neuropathy is demyelinating optic neuritis secondary to multiple sclerosis (MS).
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A complex cascade of inflammatory events begins peripherally in the body.
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Activation of T lymphocytes.
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The activated cells cross the blood-brain barrier and gain access to the central nervous system.
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The initial inflammatory cascade leads to phagocytosis of the myelin sheath.
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As a result, gliotic tissue is laid down in place of missing myelin.
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This substitutive tissue lacks the conduction properties of myelin, leading to nerve impulse interruption.
Multiple Sclerosis
Symptomatology:
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Patient is typically female, white, age 20 to 40 years.
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Typically present with mild to moderate ocular pain (exaggerated upon eye movement).
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Noticeable changes in color vision in the affected eye.
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Variable unilateral loss of vision, ranging from 20/30 to no light perception.
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This is often accompanied by an afferent pupillary defect (APD).
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Visual field defect in form of cecocentral scotomas
Management:
- Intravenous steroid (methylprednisone), administered over the course of three days followed by an 11-day course of oral prednisone.
Signs:
- In acute optic neuritis:
- Disc edema
- Disc hemorrhages
- Segmental or diffuse optic disc pallor
- 2/3 of pts have normal appearance of optic disc.
- Dyschromatopsia, red color desaturation defects
- APD
