Optic neuritis is an inflammation of the optic nerve. The most common form of optic neuritis is an acute idiopathic inflammatory demyelinating optic neuropathy. This form is strongly associated with multiple sclerosis (MS) and is often the first presenting sign of the disease. Optic neuritis is sometimes due to an infectious process involving the orbits or paranasal sinuses.
In the United States, the prevalence of optic neuritis in a predominately white population is 115 per 100,000. Most cases occur in white women between the ages of 15 and 45.
Patients with idiopathic acute optic neuritis typically present with pain and unilateral visual loss over days without systemic or neurological symptoms. Pain is present in more than 90% of cases and often worsens with eye movements. The extent of vision loss can vary and is associated with a loss of color perception. One-third of cases of optic neuritis involve swelling of the optic disc, while most cases have a normal funduscopic examination with retrobulbar optic nerve involvement. As optic neuritis is usually unilateral, an afferent pupillary defect is usually present.
Pediatric Patient Considerations:
While children may experience bilateral optic neuritis more commonly, involvement of both eyes should prompt a search for other causes.
Emergency: requires immediate attention
Optic neuritis - External and Internal Eye
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Synopsis
Codes
ICD10CM:
H46.9 – Unspecified optic neuritis
SNOMEDCT:
66760008 – Optic neuritis
H46.9 – Unspecified optic neuritis
SNOMEDCT:
66760008 – Optic neuritis
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Hypertensive optic neuropathy – Usually bilateral optic disc swelling and hemorrhages.
- Leber's stellate neuroretinitis
- Anterior ischemic optic neuropathy – Usually painless loss of vision.
- Lyme disease (see Lyme keratitis)
- Papilledema – Usually bilateral and not associated with pain or color vision defects.
- Leber optic neuropathy – Usually affects young males.
- Orbital or optic nerve tumor (see, eg, optic nerve sheath meningioma)
- Toxic optic neuropathy – Also known as tobacco-alcohol amblyopia but may also be seen secondary to other toxins including isoniazid (INH), ethambutol, chloroquine, and chlorpropamide.
- Intracranial mass
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Management Pearls
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
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References
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Last Updated:05/03/2020
Emergency: requires immediate attention
Optic neuritis - External and Internal Eye