Uveitis

What is uveitis?

Uveitis is a condition that causes inflammation (swelling) in a part of the eye called the uvea (or uveal tract). 

The eye is made up of different layers of tissue and filled with a clear jelly-like substance. The uvea is the middle layer that includes the iris (the coloured part of the eye).

Uveitis sometimes affects one eye more than the other,  or may only affect one eye at first with the other eye following. Symptoms may be asymptomatic in children and in young people. Symptoms in adults may include eye pain, redness, sensitivity to light and blurred vision. With early diagnosis and prompt treatment, most people recover well with no lasting eye damage. However, if left untreated, uveitis can lead to permanent sight loss. 

Possible causes of uveitis include an infection, injury to the eye, or an autoimmune or inflammatory condition. But in most cases, the cause is unknown. The condition can affect people of all ages, including children.

Uveitis is relatively rare, affecting around two to five in every 10,000 people each year in the UK. However, it remains a leading cause of blindness worldwide.

What are the different types of uveitis?

There are different types of uveitis, depending on which part or parts of the uvea are affected:

• Anterior uveitis – inflammation of the iris (known as ‘iritis’), or both the iris and cilary body (the ring of muscle behind the iris; known as ‘iridocyclitis’). This is the most common form of uveitis and is usually less serious than other types.
• Intermediate uveitis – inflammation of the area behind the ciliary body and the part of the retina (the light sensitive tissue at the back of the eye) responsible for peripheral vision (known as the ‘peripheral retina’). It usually affects children, teenagers and young adults, but may also occur in older age.
• Posterior uveitis – affects the choroid (the supportive layer of blood vessels underneath the retina) and/or the retina. This is a severe type of uveitis and can seriously affect vision.
• Panuveitis – inflammation of all parts of the uvea. This is the most severe type of uveitis which can lead to vision loss.  

Uveitis can also be categorised by how long it lasts and how quickly it develops:

• Acute uveitis – starts suddenly but improves within three months. It can recur, meaning there may be repeated flare ups (known as ‘acute relapsing’), with gaps of a few months in between.
• Chronic uveitis – persistent inflammation (over three months) with acute relapse within three monthsafter discontinuing treatment, and symptoms that can vary over time. 

What causes uveitis?

Uveitis can develop for many reasons, but in most cases, the cause is unknown (idiopathic). Many cases are linked to an overactive immune system, which mistakenly triggers inflammation in the eye or eyes. Less commonly, uveitis can be caused by infection, injury or surgery.

If a specific cause is identified, it may be one of the following:

• Autoimmune or inflammatory conditions – either just in the eye or associated with systemic causes such as multiple sclerosis, inflammatory bowel disease, psoriasis (an inflammatory skin condition), systemic inflammatory diseases like Sarcoidosis and Behcet’s disease or some types of arthritis (joint inflammation) in children and adults.
• Infections – bacterial, viral, fungal or parasitic infections, such as syphilis, tuberculosis (TB), toxoplasmosis or herpes simplex virus. Infection-related uveitis usually only affects one eye at a time.
• Eye injury or surgery – damage to the uvea from an eye injury or surgery can trigger uveitis.
• Medications – some medications may increase the risk of developing uveitis, such as clarithromycin, fluconazole and ritonavir or immunotherapies for cancer treatment.

Am I at risk of developing uveitis?

Uveitis can affect anyone at any age, but the chances of developing it increase with age. It’s most common in adults aged between 20 and 59 years.

People who smoke cigarettes may be more likely to develop uveitis, and those who do may find it more difficult to control.

What are the signs and symptoms of uveitis?

The symptoms of uveitis can vary depending on which parts of the uvea are affected. They may affect one or both eyes – and can develop suddenly, in hours or days, or gradually, over weeks or months. In some cases, uveitis causes no symptoms at all, and the signs are spotted during a routine eye examination.

Possible signs or symptoms of uveitis include:

• Eye pain – this can range from a mild ache to intense discomfort.
• Eye redness – having red eye(s).
• Sensitivity to light – being very sensitive to bright light, also known as photophobia.
• Blurred or cloudy vision – which can lead to decreased vision.
• Floaters – dark, floating spots that drift across the field of vision .
• Loss of vision – uveitis can lead to permanent vision loss and blindness.

If you experience any of these symptoms, contact your GP or optometrist as soon as possible, especially if you’ve had uveitis before. Early diagnosis and prompt treatment can help to improve the chances of a successful recovery.

Is uveitis serious?

Uveitis can be serious, especially if left untreated, as it may lead to permanent vision loss and blindness. With prompt treatment, most people with anterior uveitis will get better quickly, but it can come back over time. For intermediate, posterior and pan uveitis, which has a higher risk of vision loss, a more prolonged treatment course is required to maintain remission.

Early diagnosis and treatment are crucial to help prevent long-term complications like cataracts, glaucoma, amblyopia (in children) and macular oedema. If you experience any symptoms, it’s important to seek medical advice as soon as possible.

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How is uveitis diagnosed?

If a GP or optometrist suspects you may have uveitis, they'll usually refer you to an eye specialist (ophthalmologist) for further tests.

The ophthalmologist will start by carrying out a comprehensive eye examination. They will also review your medical history, ask questions about any symptoms, and check if you’ve had any recent infections or injuries. Depending on your symptoms and possible causes, they may recommend further tests to confirm or rule out certain eye and/or other wider health conditions.

Tests for diagnosing uveitis may include:

• Slit lamp microscopy – a special piece of equipment called a slit lamp is used to magnify and illuminate the front of the eye to check for signs of inflammation.
• Fundoscopy – after widening (dilating) the pupil using eye drops, the doctor will shine a bright light into the eye to examine the back of the eye.
• Optical coherence tomography (OCT) scan – this specialised imaging test uses light waves to take detailed pictures of the retina and choroid to look for changes to these structures.
• Fluorescein angiogram – this procedure examines the blood vessels and blood flow inside the eye. A doctor will inject a coloured dye into a vein into your arm, which will travel to the blood vessels in the eye. A special camera captures images of the inside of the eye to look for any signs of swelling or abnormalities.
• Blood tests – to look for signs of infections or changes in the blood that may indicate an autoimmune or inflammatory condition.
• Imaging scans – such as chest X-rays, computed tomography (CT) or magnetic resonance imaging (MRI) scans, which will help identify problems affecting other parts of the body.

If your ophthalmologist suspects you may have another underlying health condition that’s the cause of your uveitis, you may be referred to other specialists for further tests.

What are the treatments for uveitis?

Treatment for uveitis varies from person to person depending on the type of uveitis, how severe it is, and its underlying cause, if this is known. The main goals of treatment are to reduce inflammation, relieve symptoms and prevent vision loss. In some cases, treatment may be needed for months to years. Some of the treatments used for uveitis can have side effects, so regular follow-up appointments are necessary to monitor for any problems.

Treatment options include:

• Steroid medications – medications called corticosteroids (or ‘steroids’) can help to reduce inflammation in the eye. A short course of eye drops is often enough to treat anterior uveitis. But in more severe cases, pills (taken by mouth) or an injection into or around the eye may be needed.
• Pain medications – eye drops to relieve pain are commonly prescribed. These may include medications that prevent spasms in parts of the eye.
• Immunosuppressants and biologic therapy – if steroids are ineffective or unsuitable, medicines that work by suppressing parts of the immune system may be prescribed.
• Antimicrobial medications – if uveitis is caused by an infection, drugs such as antibiotics or antiviral medications may be used to treat the infection.
• Surgery – very rarely, surgery may be required to remove some of the affected tissues in the eye or treat certain complications related to uveitis.
• Steroid implants – for severe or recurring uveitis, a small implant may be placed inside the eye with surgery. This device will release a regular small dose of steroid medication into the eye over time.

While most cases of uveitis, especially anterior uveitis, will respond quickly to treatment and cause no further problems, there is still a risk of complications. The risk is higher in people with intermediate or posterior uveitis, or who have repeated episodes of uveitis. Potential complications of uveitis include loss of vision, cataracts, glaucoma, amblyopia and macular oedema.

What research is there into uveitis?

At Fight for Sight, we fund cutting-edge research to better understand who is most at risk of uveitis, and to develop better methods to diagnose, monitor and treat the condition. Some of our current and past projects include:

• Dr Ameenat Lola Solebo at University College London is leading a study to find out whether advanced imaging methods and artificial intelligence (AI) could help improve the detection of uveitis in children with juvenile idiopathic arthritis. This research could ultimately lead to earlier diagnosis for children at high risk of developing the condition, improving their chances of successful treatment.
• Professor Lucy Wedderburn at University College London led a study that investigated why some children with juvenile idiopathic arthritis develop uveitis and others do not. This research could ultimately lead to targeted monitoring and treatment for children most at risk of developing uveitis.
• Dr Gareth Jones at the University of Bristol led a study that explored the biological mechanisms behind inflammatory types of arthritis and uveitis. The team identified that inflammatory cells infiltrate the eye during arthritis, offering a possible approach for treatment or prevention. An improved understanding of why people with conditions that cause joint inflammation often go on to develop uveitis could help improve the diagnosis or treatment of both conditions in the future. 

Through these projects, we are working towards earlier diagnosis, more effective treatments, and better outcomes for people affected by uveitis.