What Is Optic Neuritis?
Optic neuritis is an inflammation of the optic nerve, a bundle of nerve fibers that carry images from your retina to your brain. Each fiber carries part of the visual information to the brain. In optic neuritis, some or all of the nerve fibers become inflamed and do not function properly, and vision becomes blurred. Vision can range from near normal to very poor depending on the number of inflamed nerve fibers.
- Blurred vision in one or both eyes especially after exercising or taking a hot bath
- Dim vision as if the lights were turned down
- Abnormal color vision with colors appearing dull and faded
- Pain behind the eye, particularly when moving the eyes
The symptoms described above may not necessarily mean that you have optic neuritis. However, if you experience one or more of these symptoms, contact your ophthalmologist for a complete exam.
Various diseases and conditions may cause optic neuritis, including autoimmune diseases such as multiple sclerosis, neuromyelitis optica, sarcoidosis, and vasculitis. Sometimes optic neuritis occurs in the setting of an infection. In many cases, however, the cause of optic neuritis is not known.
Optic neuritis is more common in women under 40 years old. However, other risk factors for optic neuritis depend on the underlying cause.
Tests and Diagnosis
A comprehensive eye exam is necessary to determine the cause of optic neuritis. This includes a complete medical history, assessment of visual acuity, color vision, side vision, and pupil reaction. By looking in the back of your eye with an instrument called the ophthalmoscope, your ophthalmologist may determine that the optic nerve appears swollen. Additional testing such as MRI of the orbits and brain, visual brain wave recordings, and blood tests may be necessary.
Treatment and Drugs
Treatment is aimed at correcting the underlying cause. Corticosteroids are sometimes used to increase the rate of recovery, but in most cases corticosteroid treatment will not affect the amount of vision that will eventually return. Most patients return to near normal vision.
Reviewed by Lindsey B. De Lott, M.D.