Eye Nerve Inflammation (Optic Neuritis)

What is optic neuritis?

Optic neuritis is inflammation (swelling) of the optic nerve. The optic nerve is located behind the eye, and sends visual images to the brain.

What is the cause?

Optic neuritis may be caused by multiple sclerosis (MS). MS causes your body to attack the outer coating of your nerves (called myelin). This leads to inflammation and problems with nerve function. When this happens in the optic nerve, you can have problems with your vision.

Other causes of optic neuritis include:

• viral infections, including chickenpox, herpes and measles
• bacterial infections, such as cat-scratch disease
• other infections, including Lyme disease, Syphilis, and Tuberculosis (TB)
• inflammation of blood vessels (called vasculitis)
• infections of nearby structures such as the sinuses (sinusitis) or brain (meningitis or encephalitis)
• radiation treatment for other medical problems

In some cases, the cause for optic neuritis is not found. This is called idiopathic optic neuritis.

What are the symptoms?

Optic neuritis usually causes painful vision loss in one eye, which may worsen over several days. The pain is usually worse when you move your eye. You may also notice that colors look washed out or that light looks dimmer in one eye. You may notice that you are missing portions of your vision in one eye. If the problem is being caused by MS, you may have other symptoms, including weakness, numbness, or tingling. Sometimes your symptoms are worse during exercise or a hot shower.

How is it diagnosed?

Your healthcare provider will ask about your symptoms, examine your eyes, and perform tests to identify the cause. Your healthcare provider may diagnose optic neuritis from your history and exam and may not order many additional tests. Tests you may have are:

• an exam with a microscope to look at the front of your eye
• an exam of the way your pupils react to light (Optic neuritis makes your pupil react abnormally to light.)
• a dilated exam using drops to make your pupil larger to look in the back of your eye
• photographs to document the appearance of your optic nerve
• a visual field test to test your peripheral field of vision (In this test, you are shown small bright spots of light in the corners of your vision and asked to press a button when you can see them.)
• an MRI to look at your optic nerve and your brain (The results of your MRI can help your healthcare provider decide if you have, or are at risk for, MS.)
• a lumbar puncture (spinal tap) to check the fluid that surrounds your brain and spinal cord (the CSF or cerebrospinal fluid) to look for inflammation and causes of the inflammation
• other tests, including a test for TB, may be ordered to help your healthcare provider figure out the cause of the optic neuritis

You may be referred to a neuro-ophthalmologist (a healthcare provider who specializes in the eye and its relationship to the brain) or a neurologist.

How is it treated?

If the optic neuritis is caused by an infection, your provider will treat the infection.

You may receive IV steroids for 3 days, followed by steroid pills by mouth for a short time. For some people, this helps speed up recovery of vision, and may decrease the chance of developing MS over the next several years.

If your MRI shows widespread inflammation, which could be a sign of MS, you will be referred to a neurologist. Treatment might include medicines that affect the immune system.

How long will the effects last?

In most cases, your vision will recover to the point where you will not notice any problems. People with severe optic neuritis may have permanent loss of vision and have trouble seeing color with the affected eye. There are no medicines or surgeries to reverse these changes.

How can I take care of myself?

• Follow your treatment plan.
• Keep all appointments for provider visits or tests.

When should I call my healthcare provider?

If you have loss of vision, call your eye care provider right away. If you have symptoms such as numbness or weakness, speak with your healthcare provider or go to the nearest emergency room.