Condition Basics

What is optic neuritis?

Optic neuritis is inflammation of the optic nerve, which lies at the back of the eye. This nerve carries visual information from the eye to the brain. If it's inflamed, you may have blurred or double vision or even loss of vision.

What causes it?

Your doctor may not know what caused this problem with your eye. In some cases, a virus infects the optic nerve. Sometimes the body's defences (immune system) mistakenly attack the body's own cells, such as the nerves.

Many people with multiple sclerosis (MS), an immune system disease, have optic neuritis at some point. It can be the first symptom of MS.

What are the symptoms?

Optic neuritis may cause partial or total loss of vision, usually in one eye. You may have pain when you move your eye.

When vision loss is partial, you may have:

• Loss of vision in the centre of the visual field (central scotoma).
• Changes in how you see colour. Bright colours may look dull.

Symptoms usually get worse over a period of a few hours or a few days. Then they may not change for several weeks or months.

How is it diagnosed?

Your doctor can find out if you have optic neuritis by doing a physical exam, including an eye exam. The doctor will also ask questions about your symptoms and past health. The doctor may use eyedrops to dilate your eyes during the exam.

Imaging tests such as an MRI may help the doctor see the optic nerve and the brain. This can help the doctor find the cause of the condition.

How is optic neuritis treated?

Because optic neuritis often improves on its own, your doctor may just want to wait and watch your symptoms. Or you may get medicine to reduce the swelling of your optic nerve. If you have a condition like multiple sclerosis, your doctor may suggest treatment for that. In any case, your doctor will carefully keep track of your condition.