Patient education: Optic neuritis (The Basics)

What is optic neuritis? — Optic neuritis is a condition that causes vision problems, eye pain, and other symptoms. It happens when the nerve that goes from the eye to the brain gets inflamed (figure 1). This nerve is called the "optic nerve."

Optic neuritis is common in people who have a disease called "multiple sclerosis" (called "MS" for short). It can also happen in people who have no other health conditions.

Optic neuritis sometimes happens to people who have conditions other than MS. This is not common. The conditions include:

●Infections – Children are more likely to get optic neuritis after an infection, such as chickenpox or the flu.

●Diseases that affect the body's infection-fighting system (called the "immune system") – These include lupus and sarcoid.

What are the symptoms of optic neuritis? — The main symptoms of optic neuritis are:

●Vision loss – A person with optic neuritis usually has trouble seeing clearly from 1 or both eyes. Optic neuritis usually happens in 1 eye at a time. But it sometimes happens in both eyes.

Vision usually gets worse for several hours or days. Most people do not lose all their vision. Vision usually starts to get better in a few weeks.

●Eye pain – The eyes might hurt more when they move. Pain usually starts when vision starts to get worse. As vision gets better, the pain goes away.

Less common symptoms include:

●Seeing flashes or flickers of light

●Having trouble seeing colors – You might think that bright colors look dark.

Should I see a doctor or nurse? — See your doctor or nurse right away if you start to lose your vision.

Will I need tests? — Yes. Doctors will do tests to see if optic neuritis is the cause of your symptoms. They will also check for signs of MS. This is because optic neuritis can be the first symptom of MS.

You will have the following tests:

●Eye exam – During this exam, the doctor will check your vision. They will do tests to measure your side or "peripheral" vision and how well you see colors. The doctor will also examine the back of your eye, where the optic nerve is, to check for signs of optic neuritis. For your eye exam, you might get special eye drops that make your pupils open up. (When your pupils are open, it is easier for the doctor to see the different parts of the inside of your eye.)

●MRI of the brain – This is an imaging test that creates pictures of the brain. It can show changes to the optic nerve and brain. It can help doctors find MS or another condition that is causing the optic neuritis.

●Blood tests – Doctors sometimes do these to look for signs of MS or conditions that sometimes happen with MS.

Some people also have a test called a "lumbar puncture." Another name for this test is a "spinal tap." In this procedure, a doctor puts a thin needle into your lower back and takes out a small amount of spinal fluid. Spinal fluid is the fluid around your brain and spinal cord. Lab tests of the fluid can tell the doctor more about what is causing the optic neuritis. Most people do not need this test, but some do.

How is optic neuritis treated? — Optic neuritis usually gets better without treatment. This can take a few weeks or many months.

Doctors can treat severe optic neuritis with steroid medicines given through a thin tube that goes into a vein, called an "IV." The medicines help the optic neuritis go away faster.

If you have optic neuritis and your MRI shows you are at high risk of getting MS, your doctor might give you medicines. These medicines can slow down the MS or keep it from happening. They include interferon beta-1a (sample brand names: Avonex, Rebif), interferon beta-1b (sample brand names: Betaseron, Extavia), or glatiramer acetate (brand name: Copaxone).

Will my vision get better? — Most people start to see better in a few weeks. Within a year, most people have vision that is almost as good as before the optic neuritis. But some people have lifelong vision loss or even blindness.

About 1 of every 3 people who get optic neuritis gets it again later.

Will I get MS? — About half the people who get optic neuritis get MS in the next 15 years. If the results of your MRI are normal, you have a lower chance of getting MS. If the MRI shows changes to the optic nerve and brain, you have a higher chance of MS. People with more changes have a higher risk than people with just a few.

More on this topic

Patient education: Multiple sclerosis in adults (The Basics)

Patient education: Vasculitis (Beyond the Basics)