Eyes - uveitis

Uveitis is inflammation of the middle layer of tissue in the eye, which extends from the iris at the front of the eye to the retina and choroid at the back of the eye.

Iritis is a type of uveitis. It is inflammation of the iris, the coloured part of the eye. It is more correctly called anterior uveitis. The cause is unknown in about 40 per cent of cases, but may include infections, autoimmune disorders, arthritis and skin disease.

Iritis symptoms typically begin suddenly and can include a red eye, eye pain, light sensitivity, blurred vision and a small or distorted pupil. Attacks typically only involve one eye at a time. Without correct treatment, iritis can cause permanent vision problems. Young and middle-aged people are most commonly affected.

There is no cure for iritis, but treatment of individual episodes can control inflammation and prevent complications. However, iritis often comes back.

Types of uveitis

There are a number of different types of uveitis, including:

• anterior uveitis – inflammation of the iris, also commonly known as iritis. It is the most common pattern of uveitis, accounting for 90 per cent of people with uveitis
• intermediate uveitis or pars planitis – inflammation involving the vitreous gel. Vitreous gel fills the majority of the eye cavity and the pars plana, which is the tissue that bridges the gap between the front and back of the eye
• posterior uveitis or chorioretinitis – inflammation of the choroid, retina and other structures at the back of the eye. The choroid is the major layer of blood vessels within the eyeball and is commonly involved in inflammation at the back of the eye.

Causes of uveitis

In many cases, the cause of uveitis is not known. Common known causes include:

• autoimmune disease – such as arthritis, Reiter’s syndrome, sarcoidosis and ankylosing spondylitis
• infection – such as herpes virus infection, syphilis, tuberculosis and Lyme disease
• eye problems – such as an eye infection, a scratch to the cornea or an ulcer on the eye’s surface
• isolated ocular autoimmune disorder – the immune system attacks the iris for reasons unknown, even when no other autoimmune disease is present.

Symptoms of uveitis

Uveitis can involve one or both eyes. Symptoms typically come on suddenly and can include:

• red eye
• watery eye
• eye pain
• light sensitivity
• blurred vision
• small or distorted pupil.

Diagnosis of uveitis

Diagnosis of uveitis depends on a thorough eye examination. If uveitis is diagnosed and treated in its early stages, there is often no loss of vision.

Treatment of uveitis

It takes six to ten weeks to treat an episode of anterior uveitis. Treatment of intermediate and posterior uveitis is more complex and can take many months or even years. You need to be closely monitored during treatment to minimise the development of complications.

Treatment may include:

• corticosteroids – to reduce inflammation. Most people with uveitis respond to steroid eye drops. Those with posterior uveitis often require local injections of corticosteroids or oral steroids. Some people require additional immunosuppressive medications
• cycloplegic medication – eye drops that dilate the pupil to prevent it sticking to the lens of the eye. These drops reduce the risk of scarring between the pupil and the lens
• treatment of an underlying condition – uveitis may be a sign of an undiagnosed disease or infection somewhere else in the body. It is important that you have a range of tests (such as blood tests and x-rays) to find out if there is an underlying cause of your uveitis. If so, appropriate treatment should be given.

Complications of uveitis

Complications associated with uveitis include:

• glaucoma – this involves a harmful build-up of fluid within the eyeball. Aqueous humour is fluid that nourishes the iris. It is located inside a small chamber just behind the cornea. Glaucoma occurs when aqueous humour is unable to drain properly. This can damage the optic nerve and cause vision to narrow or cause blank areas to appear in the visual field
• cataract – the lens, situated behind the iris, becomes cloudy. Treatment includes surgery to replace the lens
• macula oedema– the central retina becomes swollen and waterlogged, resulting in blurriness.

Where to get help

• Your GP (doctor)
• Ophthalmologist
• Local general hospital or specialist eye hospital