Optic neuritis, an inflammation of the optic nerve in one or both eyes, may interfere with the transmission of nerve impulses from the optic nerve to the brain, causing sudden blurry vision or other visual impairment. Usually, central vision and color perception are affected the most.
Although rare, some cases progress from blurring to total temporary blindness in the affected eye(s) within a matter of days. Optic neuritis may also result in demyelination—a progressive loss of the protective sheaths around the optic nerve.
Underlying conditions that can damage the optic nerve include multiple sclerosis (MS) and various infections, such as syphilis. In the majority of cases, symptoms disappear spontaneously and normal or nearly normal vision is restored within a few months. But attacks may recur and eventually lead to permanent vision loss, depending on the cause.
What Causes Optic Neuritis?
- An episode of optic neuritis may be one of the earliest indications of multiple sclerosis (MS), a disease in which the protective sheaths (myelin) surrounding the nerves are gradually destroyed. An estimated 35 percent of men and 75 percent of women who develop optic neuritis will develop MS within the ensuing 15 years, and 40 percent of MS patients experience at least one episode of optic neuritis. (Although MS is a common cause of optic neuritis, a number of other conditions can also trigger it.)
- Optic neuritis may also result from inflammation due to infection of the tissues near the optic nerve.
Symptoms of Optic Neuritis
- Impaired central vision or color perception in one or both eyes
- Partial or total vision loss within a period of several hours to several days. If both eyes are involved, the second eye may be affected several days or weeks later
- Pain when moving or touching the affected eye or eyes, especially in the first several days after the onset of symptoms
- Visual flashing sensations caused by eye movement or sound
- Sore eye
- Central blind spot (scotomas)
- Decreased vision after exercise, hot bath or shower
Prevention of Optic Neuritis
There are no known ways to prevent optic neuritis.
Optic Neuritis Diagnosis
- A thorough eye examination is required. Inspection with an ophthalmoscope (a lighted instrument that permits viewing of the internal structures of the eye) often reveals only normal conditions during the early stages, but later examinations may uncover characteristic signs of optic neuritis or its aftereffects.
- Visual field and color perception tests may be performed; the reaction of the pupil to light is assessed.
- Tests may be required to rule out serious underlying diseases associated with optic nerve damage. If multiple sclerosis or temporal arteritis is suspected, the doctor will recommend further testing.
- Visually Evoked Potential (VEP, VER) tests are performed to detect the speed of nerve transmissions down the optic nerve.
- MRI (Magnetic Resonance Imaging) or CT (Computed Tomography) Scan of the brain may be performed when the doctor suspects multiple sclerosis or another neurologic cause.
How to Treat Optic Neuritis
- In most cases, partial or full recovery of vision will occur within several months without treatment.
- Corticosteroids may be prescribed to speed natural recovery. Side effects, including increased recurrences, keep this treatment limited to select patients.
When to Call a Doctor
If you experience any vision loss or impairment, contact an ophthalmologist immediately.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media