Optic neuritis is inflammation of the optic nerve.
Multiple sclerosis is the most common cause.
Loss of vision may develop, and there may be pain with eye movement.
Magnetic resonance imaging is done.
Corticosteroids may be given.
(See also Overview of Optic Nerve Disorders.)
Causes of Optic Neuritis
Optic neuritis is most common optic nerve disorder in adults younger than 50. Optic neuritis is most often caused by multiple sclerosis. Some people with optic neuritis have a known diagnosis of multiple sclerosis, while other people who have optic neuritis are later found to have multiple sclerosis. Optic neuritis may also be caused by the following:
Neuromyelitis optica (NMO)
Myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD)
Infections such as viral encephalitis (especially in children), meningitis, syphilis, sinusitis, tuberculosis, and human immunodeficiency virus (HIV)
Medications such as tumor necrosis factor (TNF)-alpha inhibitors or checkpoint inhibitors
Other autoimmune conditions such as systemic lupus erythematosus
However, the cause of optic neuritis is often unknown.
Symptoms of Optic Neuritis
Optic neuritis causes vision loss, which may be severe and may occur in one or both eyes. Loss of vision may increase over several days. Vision in the involved eye or eyes can range from almost normal to complete blindness. Color vision may be particularly affected, but the person may not realize it. Most people have mild eye pain, which often feels worse with eye movement.
Depending on the cause, vision usually returns within 2 to 3 months but not always completely. Some people have repeat episodes of optic neuritis.
Diagnosis of Optic Neuritis
A doctor's evaluation
Usually magnetic resonance imaging
Diagnosis involves examination of the reactions of the pupils and observing the back of the eyes with a light with magnifying lenses (ophthalmoscope). The head of the optic nerve at the back of the eye (optic disk) may appear swollen. Testing the field of vision usually reveals loss of a portion of the visual field.
Magnetic resonance imaging (MRI) of the brain may show evidence of multiple sclerosis; myelin oligodendrocyte glycoprotein antibody–associated disease (also called MOGAD), a neurologic, immune-mediated disease in which the optic nerve becomes inflamed; or neuromyelitis optica (also called NMO), a rare immunologic disease that damages the spinal cord and optic nerve. MRI of the brain and orbits will usually show abnormality of the optic nerve. Spinal cord imaging may be done in people with neurologic symptoms.
Treatment of Optic Neuritis
Sometimes corticosteroids
In some instances, corticosteroids are given by vein to treat optic neuritis. After a few days, corticosteroids can be given by mouth. These drugs may hasten recovery. If the vision loss is severe and does not start to resolve after corticosteroids, plasma exchange can sometimes be used. If the optic neuritis is related to multiple sclerosis, NMO, MOGAD, or an infection, the underlying disease should also be treated.
Magnifiers, large-print devices, and talking watches (low-vision aids) may help people with loss of vision.
