Iritis

Uveitis is inflammation of the middle layer of the eye, called the uvea or uveal tract.

The uvea is made up of the iris (coloured part of the eye), the ciliary body (ring of muscle behind the iris) and the choroid (layer of tissue that supports the retina).

Common signs of uveitis include:

• pain in one or both eyes
• redness of the eye 
• blurred vision
• sensitivity to light (photophobia)
• floaters (shadows that move across your field of vision)

Read more about the symptoms of uveitis.

When to seek medical advice

Contact your GP as soon as possible if you have persistent eye pain or you notice an unusual change in your vision, particularly if you've had previous episodes of uveitis.

The sooner uveitis is treated, the more likely the condition can be successfully treated.

After examining your eye, your GP may refer you to a specialist in eye conditions called an ophthalmologist. An ophthalmologist will examine your eye in more detail and may suggest further tests to help identify the cause of the condition.

Read more about diagnosing uveitis.

Why does uveitis happen?

There are a wide range of potential causes for uveitis. Many cases are thought to be the result of a problem with the immune system (the body's defence against illness and infection), although a specific cause is not always identified.

Less common causes of uveitis include an infection or injury to the eye.

Read more about the causes of uveitis.

Types of uveitis

The type of uveitis depends on which part of the eye is affected:

• anterior uveitis – this is inflammation of the iris (iritis) or inflammation of the iris and the ciliary body (iridocyclitis), and is the most common type of uveitis, accounting for about three out of four cases
• intermediate uveitis – this affects the area behind the ciliary body and the retina
• posterior uveitis – this affects the area at the back of the eye, the choroid and the retina

In some cases, uveitis can affect the front and back of the eye. This is known as panuveitis.

How is uveitis treated?

The main treatment of uveitis is steroid medication (corticosteroids), which can reduce inflammation inside the eye.

Several different types of steroid medication may be used, depending on the type of uveitis you have. Eye drops are often used for uveitis affecting the front of the eye, whereas injections, tablets and capsules are more often used to treat uveitis affecting the middle and back of the eye.

In some cases, other treatments may also be needed in addition to corticosteroids. These include eye drops to relieve pain, a type of medication called an immunosuppressant, and even surgery.

Read more about treating uveitis.

Complications

Although most cases of uveitis respond quickly to treatment and cause no further problems, there is a risk of complications.

The risk is higher in people who have intermediate or posterior uveitis, or who have repeated episodes of uveitis.

Complications of uveitis include permanent damage of the eye and some loss of vision.

It's estimated that the more serious types of uveitis are responsible for 1 in every 10 cases of visual impairment in the UK.

Read more about the possible complications of uveitis.