Uveitis

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

Introduction

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 doctor 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 doctor 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.

Symptoms

One or both eyes may be affected by uveitis. The symptoms can develop suddenly or gradually over a few days.

Signs of uveitis include:

  • a painful red eye – the pain can range from mild aching to intense discomfort, and reading or other tasks that require you to focus your eye can make the pain worse
  • blurred or cloudy vision
  • sensitivity to light (photophobia)
  • floaters – shadows that move across the field of vision
  • loss of peripheral vision – the ability to see objects at the side of your field of vision
  • seeing flashing lights

However, symptoms of pain and redness are usually only present in the most common form of uveitis affecting the front of the eye (anterior uveitis).

When to seek medical advice

Contact your doctor 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 less likely it is that a person will have permanent problems with their vision.

Causes

Uveitis occurs when the eye becomes inflamed.

Inflammation is when areas of the body become warm, red and swollen in response to a perceived threat.

This is sometimes the result of an infection, but most cases of uveitis are thought to be related to a problem with the immune system (the body's defence against infection and illness).

If the specific cause of uveitis is not identified, it is known as idiopathic uveitis. But most experts suspect that idiopathic uveitis is also related to a problem with the immune system.

Immune system problems

Uveitis often develops in people who have an underlying autoimmune condition (where the immune system mistakenly attacks healthy tissue).

Autoimmune conditions known to cause uveitis in some people include:

  • ankylosing spondylitis – an autoimmune condition mainly affecting the spine
  • reactive arthritis – a type of arthritis often affecting the joints, genitals and eyes
  • conditions that cause bowel inflammation, such as Crohn's disease and ulcerative colitis
  • psoriasis – a skin condition caused by the immune system disrupting the normal production of skin cells
  • multiple sclerosis – an autoimmune condition mainly affecting the nerves
  • Behçet's disease](yourmd:/condition/behcets-disease/introduction) – a rare condition that causes [mouth ulcers and genital ulcers

Infection

A minority of uveitis cases are caused by an infection, such as:

  • toxoplasmosis – an infection spread by parasites
  • the herpes simplex virus – the virus responsible for cold sores and genital herpes
  • the varicella-zoster virus – the virus that causes chickenpox
  • cytomegalovirus – a common infection that doesn't usually cause any noticeable symptoms in most people, but can cause sight-threatening uveitis in people with a reduced immune system

Other causes

In some cases, uveitis is not caused by an infection or a problem with the immune system. For example, uveitis can also be caused by:

  • trauma or injury to the eye(s)
  • some types of cancers, such as lymphoma, although this is a very rare cause of uveitis

Diagnosis

If you visit your doctor with an eye problem, they will examine your eyes and ask you about your symptoms and medical history.

If a diagnosis of uveitis is suspected, it's likely that you'll be referred for an immediate appointment with an ophthalmologist (a doctor who specialises in treating eye conditions).

Slit-lamp exam

The ophthalmologist should be able to confirm a diagnosis of uveitis using a piece of equipment called a slit-lamp. A slit-lamp consists of a microscope and a powerful beam of light.

The ophthalmologist will use the light to illuminate your eye before examining it under the microscope to check for any abnormalities.

A slit-lamp examination can also identify the area of the eye that is affected by uveitis, which will help determine the treatment required.

Further tests

If a diagnosis of uveitis is confirmed, you may need further tests to try to identify the cause of the condition. This may include scans of your eye(s), X-rays and blood tests.

Knowing the cause of your uveitis will also help determine what treatment is needed.

Read more about treating uveitis.

Treatment

Treatment for uveitis will depend on which areas of the eye are affected and what caused the condition.

Medication is the main treatment, but surgery can be used in particularly severe cases.

Steroid medication

Steroid medication (corticosteroids) is used to treat most cases of uveitis. A medicine called prednisolone is usually used.

Corticosteroids work by disrupting the normal functioning of the immune system so that it no longer releases the chemicals that cause inflammation.

Corticosteroids are available in a number of forms, and the type used will often depend on the areas of your eye that are affected by uveitis.

Corticosteroid eye drops

Corticosteroid eye drops are usually the first treatment recommended for cases of uveitis affecting the front of the eye (anterior uveitis) that are not caused by an infection.

Depending on the severity of your symptoms, the recommended dose can range from having to use eye drops every hour to once every two days.

You may experience temporary blurred vision after using corticosteroid eye drops. If this happens, don't drive or operate machinery until your vision returns to normal.

Don't stop using your eye drops until your doctor or ophthalmologist advises that it's safe to do so, even if your symptoms disappear. Stopping treatment too soon could lead to your symptoms returning.

Corticosteroid injections

If the middle or back of your eye is affected (intermediate or posterior uveitis) or your symptoms fail to respond to corticosteroid eye drops, you may need to have corticosteroid injections.

The injection is given to the side of the eye. Local anaesthetic is used to numb your eye and surrounding tissue so that you won't feel any pain or discomfort.

You'll usually require one injection every two to three weeks until your symptoms start to improve.

Corticosteroid injections rarely cause significant side effects.

Oral corticosteroids

Oral corticosteroids (tablets or capsules) are the strongest form of corticosteroids. They are usually only used if steroid eye drops and injections are ineffective or unsuitable.

While they work well in relieving inflammation, the effect is not confined to the eye, so they can cause a wide range of side effects.

Oral corticosteroids may also be recommended if it's thought that uveitis may pose a risk of permanent damage to your vision (see complications of uveitis for more information).

How long you'll have to take oral corticosteroids will depend on how well you respond to treatment and whether you have an underlying autoimmune condition. Some people only need a three- to six-week course, while others need to have a course lasting months or possibly years.

Side effects of oral corticosteroids can include weight gain, mood changes (such as feeling irritable or anxious) and osteoporosis (fragile bones).

To minimise the impact of side effects, you will be prescribed the lowest possible dose that's thought to be effective enough to control your symptoms.

Read more about the side effects of corticosteroids.

Don't suddenly stop taking your oral corticosteroids. If your doctor or ophthalmologist decides to end your treatment, they'll gradually reduce the amount of corticosteroids that you're taking.

Cycloplegic-mydriatic eye drops

If you have uveitis affecting the front of your eye (anterior uveitis), you may be given special eye drops called cycloplegic or mydriatic eye drops in addition to steroid medication.

These drops dilate your pupils and relieve pain by relaxing the muscles in your eye. They can also reduce the risk of the iris (the coloured part of the eye) "sticking" to the lens (the transparent section at the front of the eye). This can result in a condition called glaucoma, which affects vision.

However, these drops can cause some temporary blurring of your vision and problems focusing your eyes.

Treating infection

If the cause of your uveitis is known to be an underlying infection, the infection may also need to be treated.

Viruses can be treated with antiviral medication, bacterial infections can be treated with antibiotics, and fungal infections can be treated with antifungal medication.

The medications will usually be used alongside appropriate steroid medication and cycloplegic or mydriatic eye drops.

Immunosuppressants

A very small number of people with uveitis fail to respond to the treatments described above. In such circumstances, a type of medication called an immunosuppressant may be recommended.

Immunosuppressants are a type of medication that suppress (control) the immune system and disrupt the process of inflammation.

If you are having steroid treatment that is causing significant side effects, immunosuppressants can also be used to allow your dose of steroids to be reduced.

Side effects of immunosuppressants include:

  • hair loss
  • skin rash
  • numbness or tingling in different parts of your body
  • loss of appetite
  • nausea and vomiting
  • high blood pressure
  • headaches

Taking immunosuppressants will make you more vulnerable to infection, so you should try to avoid close contact with anyone who has a known infection.

You should also report any symptom of a potential infection, such as a high temperature or inflammation in other parts of your body, to your doctor.

Read more about the [medications used to treat uveitis].

Surgery

In rare cases, surgery may be needed to treat uveitis. However, this is usually only recommended if you have repeated or severe uveitis, or if the condition is caused by a fungal infection.

An operation called a vitrectomy can be used to treat uveitis. This involves gently sucking out the jelly-like substance that fills the inside of the eye (the vitreous humour). It can be carried out either using general anaesthetic or local anaesthetic.

The fluid inside the eye will be temporarily replaced during the operation with either a bubble of air or gas, or a liquid substitute. Eventually, the eye will naturally replace the vitreous humour with a slightly different clear fluid called aqueous humour.

Like all operations, a vitrectomy carries a risk of complications. These include needing further surgery and an increased risk of developing cataracts (cloudy patches in the lens of the eye).

Complications

Uveitis can sometimes lead to further problems, especially if the condition is not treated properly.

People with chronic (long-term) uveitis, or the less common types of uveitis affecting the middle or back of the eye (intermediate and posterior uveitis), are most at risk of developing complications.

Complications are also more likely to occur in adults who are over 60 years old.

Some of the more common complications of uveitis are described below.

Glaucoma

Untreated uveitis can cause the iris (the coloured part of the eye) to stick to the front surface of the lens (the transparent structure that focuses the light entering your eye). This prevents fluid draining through the pupil and increases the pressure inside the eye.

The raised pressure inside your eye can damage the optic nerve (the light-sensitive layer of tissue at the back of the eye that transmits images to the brain) and disrupt your normal vision, such as causing misty vision and rings or halos to appear around lights. This is known as glaucoma.

Treatment options for glaucoma include:

  • eye drops
  • laser treatment
  • surgery

Read more about treating glaucoma.

Cataracts

The inflammation inside the eye associated with uveitis can sometimes irritate the lens of the eye, causing cloudy patches on the surface of the lens to develop. The cloudy patches are known as cataracts. They can cause symptoms such as:

  • blurred vision
  • problems seeing clearly at night
  • colours appearing unusually faint

Cataracts are usually treated using surgery to remove the affected lens and replace it with an artificial one.

See cataracts and cataract surgery for more information.

Cystoid macular oedema

Cystoid macular oedema is a complication that can affect some people with chronic uveitis or uveitis that affects the back of the eye.

Prolonged inflammation can result in a build-up of fluid inside the retina. This can disrupt its ability to function normally and lead to a painless loss of central vision. You may notice a black spot in your field of vision.

Cystoid macular oedema can be treated using corticosteroid injections or tablets.

In some cases, a person's vision will recover once treatment is initiated. However, this isn't always the case in severe cases of cystoid macular oedema. This is why the condition is a leading cause of visual impairment in people with uveitis.

Content supplied by NHS Choices