Uveitis

Uveitis is inflammation of the middle layer of the eye, which is 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).

Inflammation of the uvea usually causes a red eye, sometimes with cloudy vision, and it may be painful (see Symptoms, above, for more information).

Uveitis may be caused by an injury, infection or underlying disease (see Causes). If it is not treated, the eyesight can be seriously damaged.

Who is affected?

Uveitis can affect anyone. It particularly affects people of working age but can also occur in children.

Different 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). It is the most common type of uveitis, accounting for 75% of cases.
  • Intermediate uveitis. This affects the area behind the ciliary body and the retina. It tends to occur in childen, teenagers and young adults.
  • Posterior uveitis. This affects the area at the back of the eye, the choroid and the retina.

Acute uveitis lasts for a few weeks and can recur, whereas chronic uveitis lasts for more than three months, with symptoms that can vary from day to day.

If you have uveitis, it may have implications on your fitness to drive. 

The cause of uveitis is often unknown, but it may result from:

  • an injury to the eye (traumatic iritis), for example, a squash ball hitting the eye,
  • recent or previous eye surgery,
  • certain types of infection, or
  • a health condition (see below).

Health conditions

Uveitis may be associated with the following conditions:

  • an inflammatory or autoimmune condition (when the body attacks its own organs), such as arthritis, juvenile rheumatoid arthritis, ankylosing spondylitis (arthritis of the lower back), Reiter's syndrome, Behçet's disease, sarcoidosis, psoriasis or inflammatory bowel disease,
  • a bacterial, viral, fungal or parasitic infection such as toxoplasmosis, gastroenteritis, tuberculosis (TB), Lyme disease, syphilis or shingles, and
  • an immune-deficiency disease (when the body's immune system is impaired), such as HIV/AIDS, because this can make you prone to infection.

Your GP or ophthalmologist (eye specialist) will be able to diagnose uveitis based on your symptoms.

  • If you have anterior uveitis, the most common type, one of your eyes will be painful and red.
  • If you have one of the other, less common types of uveitis, your eye will usually not be painful.

Examination

The eye is examined with a slit lamp (a microscope designed for eye examination). White blood cells and protein in the eye fluid can be seen through the microscope if you have uveitis. As the light beam passes through the eye, the fluid inside is seen to be hazy instead of clear.

A light will be shone into the unaffected eye and this will cause both pupils to constrict. If one eye is affected by uveitis, there will be a slight pain in the eye as the pupil constricts.

There will normally be an examination of the inside of the eye to see if other parts of the eye are affected.

Uveitis must be distinguished from conjunctivitis. Conjunctivitis never affects vision (although it may cause clouding of vision if pus briefly gets onto the cornea) and it does not affect the inside of the eye, just the outside.

Tests

Blood tests, X-rays and other tests may be done to establish the cause of the uveitis.

If you have uveitis, you will have some or all of the following symptoms.

Anterior uveitis (iritis)

Anterior uveitis affects the front of the eye (usually the iris) and is the most common type. Only one eye is usually affected. Symptoms include:

  • an aching, painful, red eye. The pain can range from mild aching to intense discomfort,
  • blurred or cloudy vision,
  • a small pupil,
  • an iris (the coloured part of the eye) that may have a slightly different colour,
  • sensitivity to light (photophobia),
  • floaters (dots that move across the field of vision), and
  • headaches.

These symptoms may develop gradually over hours or days. They may be acute (lasting a few weeks) or chronic (lasting for more than three months).

Intermediate uveitis

Intermediate uveitis is the second most common type, affecting the area just behind the ciliary body and part of the retina. Both eyes tend to be affected and it is usually painless.

Symptoms can include:

  • mild redness (although there is usually no redness),
  • floaters (dots that move across the field of vision), and
  • blurred vision due to cells from the blood vessels leaking into the gel of the eye.

There is usually no redness or only mild redness associated with intermediate uveitis.

Posterior uveitis

Posterior uveitis affects the back of the eye (the choroid) where your blood vessels supply the retina. One or both eyes may be affected and it is usually painless. 

Posterior uveitis usually causes decreased vision and floaters, and sometimes retinal detachment (see Useful links) These symptoms are slower to develop and often last longer than those of anterior uveitis.

Posterior uveitis can be more damaging to the eye than other types of uveitis. It sometimes causes visual loss.

Treatment of uveitis will depend on the type of uveitis, how serious it is and the cause. Some cases will clear up with the use of eyedrops. Others may need steroid injections into the eye.

The aim of treatment is to:

  • control the inflammation,
  • relieve any pain,
  • treat any underlying condition, and
  • treat any complications that may cause visual loss.

If you have recurrent uveitis, it is important to get it treated quickly. You may be advised to keep steroid eyedrops to hand at all times.

The different treatments are outlined below.

Mydriatic eyedrops

Mydriatic eye drops, such as atropine or cyclopentolate, dilate (widen) the pupil. This helps the eye to heal, prevents the pupil from getting stuck to the lens and decreases the eye pain. Your doctor will advise how often you should use these.

Mydriatic eye drops may cause blurred vision, difficulty focusing and an increased sensitivity to light, but they are a vital part of treatment.

If the condition is diagnosed early and treated with eye drops, no visual loss should occur.

Steroid eyedrops

Steroid eyedrops help decrease the inflammation of the iris. They will be used frequently at first and then tapered off, to prevent the uveitis recurring.

Steroid eyedrops are usually not used if a virus or bacteria caused the condition.

Steroid tablets or steroid injections to the eye

Steroid tablets (such as prednisolone) or a steroid injection into the eye may be recommended in severe cases of uveitis, when eye drops have no effect. The injection is done under local anaesthetic and you can go home on the same day.

In some cases, a steroid drip (methylprednisolone) may be given in hospital.

Prolonged steroid treatment needs to be carefully monitored for side effects (see Complications).

Immunosuppressants

Immunosuppressants are drugs that suppress the body's immune system. Examples are:

  • cyclosporin,
  • azathioprine, and
  • methotrexate.

These tablets can be used alongside steroids to treat some types of uveitis.