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For further information, see CMDT Part 7-22: Optic Neuritis
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Essentials of Diagnosis
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Subacute usually unilateral visual loss
Pain exacerbated by eye movements
Optic disk usually normal in acute stage but subsequently develops pallor
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General Considerations
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Unilateral loss of vision that usually develops over a few days
Vision ranges from 20/30 (6/9) to no light perception with more severe visual loss being associated with low serum vitamin D levels
Pain behind the eye, exacerbated by eye movements
Field loss is usually a central scotoma, but a wide range of monocular field defects is possible
Particular loss of color vision
A relative afferent pupillary defect
In about two-thirds of cases, the optic nerve is normal during the acute stage (retrobulbar optic neuritis)
In one-third of cases, the optic disk is swollen (papillitis) with occasional flame-shaped peripapillary hemorrhages
Visual acuity usually improves within 2–3 weeks and returns to 20/40 (6/12) or better in 95% of previously unaffected eyes
Optic atrophy develops subsequently if there has been damage to sufficient optic nerve fibers
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Intravenous methylprednisolone (1 g daily for 3 days followed by a tapering course of oral prednisolone)
Has been shown to accelerate visual recovery but not to improve final vision
In clinical practice, however, the oral taper is not often prescribed and oral methylprednisolone may be used
Use in an individual patient is determined by the degree of visual loss, the state of the fellow eye, and the patient's visual requirements
Phenytoin may be neuroprotective in typical optic neuritis
Atypical optic neuritis due to sarcoidosis, neuromyelitis optica, herpes zoster, or systemic lupus erythematosus
Requires more immediate and prolonged corticosteroid therapy
May require plasma exchange
May require long-term immunosuppression
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