Uveitis is the inflammation of the uveal tract. The uveal tract is the name given to the part of your eye that is made up of:
- The Iris: the coloured part of your eye.
- The Ciliary Body: a small ring-like muscle that sits behind your iris.
- The Choroid: the layer of tissue between your retina and your sclera, containing blood vessels and a pigment that absorbs excess light.
Parts of your eye next to the uveal tract can also be affected. These include:
- The Retina: the light-sensitive layer lining the interior of your eye.
- The Optic Nerve: the nerve responsible for vision.
- The Vitreous Humour: the jelly-like material that fills the chamber behind your lens.
- The Sclera: the white outer layer of your eyeball.
Different Types Of Uveitis
Uveitis is classified according to the part of the uveal tract that is inflamed:
- Anterior Uveitis is when the inflammation affects the anterior part of the uveal tract at the front of the eye. This can include the iris (iritis) or the iris and the ciliary body (iridocyclitis). This is the most common type of uveitis.
- Intermediate Uveitis is when the middle part of the uveal tract or eye becomes inflamed, mainly the vitreous humour. It can also affect the underlying retina.
- Posterior Uveitis is when the inflammation affects the back of the eye. It can affect the head of the optic nerve, the choroid, and the retina. It includes chorioretinitis, retinitis and neuroretinitis.
- Panuveitis is when the inflammation affects the whole of the uveal tract.
Uveitis can also be:
- Acute: Sudden onset of uveitis which tends not to last very long (between 1 and a half to 3 months).
- Chronic: Persistent uveitis that lasts for more than three months and also relapses (comes back) within three months of stopping treatment.
- Recurrent: the disease can relapse and, at other times, it settles down.
The reason why some people develop chronic uveitis is not fully known. However, it is not thought to be due to inadequate treatment.
There are many different causes of uveitis. Uveitis is also associated with a number of other diseases. However, in up to half of cases, no specific cause for uveitis is found. This is called idiopathic uveitis.
The known causes and associations of uveitis include the following:
Autoimmune And Inflammatory Diseases
A healthy human immune system normally makes antibodies to fight off bacteria, viruses, and other germs. In people with autoimmune diseases, their immune system makes antibodies that act against the tissues of their body causing damage and inflammation. It is not clear why this happens. Some people have a tendency to develop autoimmune diseases. In these people, something might trigger the immune system to attack the body’s own tissues. It is not known what may cause this.
Autoimmune diseases that are associated with uveitis include Behçet’s syndrome and rheumatoid arthritis. Behçet’s syndrome is a condition that causes recurrent mouth ulcers. It may also affect other parts of your body including your heart, lungs, gut, joints and nervous system. It is also thought that ‘idiopathic’ uveitis might actually occur on an autoimmune basis.
People who suffer from other inflammatory diseases are also more prone to uveitis. Such diseases include reactive arthritis (including Reiter’s syndrome), sarcoidosis, ankylosing spondylitis, psoriasis and inflammatory bowel disease (including Crohn’s disease) and ulcerative colitis.
Various types of bacterial, viral and fungal infections can cause inflammation of the eye and uveitis. Infections include herpes simplex, herpes zoster, syphilis, gonorrhoea, toxoplasmosis, cytomegalovirus, tuberculosis and Lyme disease. Uveitis is rarely caused by infections.
Injury To The Eye
Uveitis can occur as part of an injury to the eye.
Uveitis that stems from either an unforeseen or inevitable side-effect from an eye treatment or surgery
Some forms of cancers are associated with inflammation and uveitis. These include leukaemia, lymphoma and malignant melanoma.
It is thought that between 17 and 52 per 100,000 people develop uveitis each year in the UK. It mostly affects people between the ages of 20 and 59 and is uncommon in children. However, uveitis can affect anyone of any age. If you have one of the underlying conditions or problems mentioned above, you are at greater risk of developing uveitis. In countries of the developed world such as the UK, uveitis is the cause of about 1 in 10 people with visual impairment.
The symptoms can vary depending on which type of uveitis you have.
This usually affects one eye. The common symptoms are eye aches and pains, redness of the eye, and not being able to tolerate bright light. You may develop blurred vision or even some visual loss, though this is usually temporary. You may develop headaches and notice that your iris is a slightly different colour. Your eye may also become watery. The symptoms tend to develop over a few hours or days.
This usually causes painless blurred vision. It is unusual to experience intolerance to light and redness of your eye. You may notice floaters, which are a common symptom. Floaters are dark shapes that you see, especially when looking at a brightly illuminated background such as a blue sky. Both eyes are usually affected in intermediate uveitis.
This commonly causes painless blurred vision. In some people, it can also cause severe visual loss. If you have posterior uveitis you may begin to see floaters, as described above. You may also develop scotomata, small areas of less sensitive or absent vision in your visual field. These areas are surrounded by normal sight. Usually, only one of your eyes is affected in posterior uveitis and symptoms tend to take longer to develop.
How Is Uveitis Diagnosed?
Uveitis is usually suspected based on the symptoms that you have. If your doctor suspects that you have uveitis, they will usually refer you to an eye specialist for further examinations. The doctor may start by testing your vision to assess if there is any difference between your eyes and if it is causing your vision to worsen.
The doctor will usually use an ophthalmoscope (a hand-held instrument) to examine the interior of your eye. This directs a beam of light into your eye, allowing the doctor to examine the inside of your eye. The doctor will usually put in some eye-drops just before the examination. The drops act to widen your pupils so that the doctor can see into your eye better. The doctor may also use a special microscope called a slit-lamp to examine your eye. If you have uveitis, the doctor will see specific changes in your eye which will allow them to make the diagnosis.
The doctor may also request some further investigations to determine the likely cause of your uveitis. These can include blood tests and X-rays.
Treatment for uveitis aims to help relieve pain and discomfort in the eye(s), treat any underlying causes, and reduce the inflammation. This may prevent permanent loss of vision or other complications. Treatment usually includes the following:
Treatment To Relieve Pain And Discomfort
- Cycloplegic Eye Drops: these are special eye drops that can be used to relieve pain by causing the pupil in your eye to dilate. The drops relax the muscle in the ciliary body, causing the pupil to dilate. As a result, pain is reduced and the inflamed iris is able to rest and recover. You may experience some side-effects. They can cause temporary blurred vision and you may experience difficulty focusing. When the effect of the drops wears off, the side-effects will disappear. The drops need to be used as frequently as every hour when uveitis is first diagnosed. If the drops are not used, the inflammation in the iris may cause it to ‘stick’ to the lens and cause permanent scarring.
- Dark Glasses: if your symptoms include photophobia (sensitivity to bright light), wearing dark glasses can help.
- Painkillers: painkillers, such as paracetamol, taken by mouth may also help.
Steroid Eye Drops
Steroid eye drops are used to reduce the inflammation. They are usually the main treatment. Although steroid eye drops normally work well, there have been some cases side-effects occurring, which are sometimes serious. Therefore, steroid eye drops are usually only prescribed by an ophthalmologist (an eye specialist) who can monitor the situation. Possible side-effects that can sometimes occur include ulcers on the cornea of the eye which can be very painful and affect your vision. Prolonged use of steroid eye drops has been know to lead to cataracts or glaucoma.
Steroids By Mouth Or Injection
In severe uveitis, steroids are sometimes given by injection into or around your eye. They may also be given by mouth. Again, these can cause side-effects if used for long periods of time. The main side-effects from steroids taken by mouth occur when they are used for more than a few weeks. They can include thinning of the skin, thinning of the bones (osteoporosis), weight gain, muscle wasting and an risk of serious infection.
If steroid treatment is needed for long term to treatment of uveitis, a second drug known as an immunosuppressive drug may be used. This can help to reduce the amount of steroids needed and help to control the uveitis if steroids are not working.
Treatment Of Underlying Conditions And Causes
Any underlying cause of your uveitis also needs to be treated (if possible). This means treating any underlying infection, inflammatory disease or autoimmune disease.
Occasionally, surgery is needed as treatment. For example, if someone has persistent floaters that are affecting their vision, the vitreous humour in the eye can be removed. Floaters tend to develop because of inflammation causing damage to
the vitreous humour. Surgery may also be used to treat the complication of cataracts that can also occur.
There are a number of new treatments for uveitis that are currently being investigated. They include drugs called TNF-alpha blockers such as etanercept and infliximab.
If uveitis is not treated quickly, it can have serious effects and can lead to permanent loss of vision. It can also lead to complications that can affect your eyesight. If complications are not detected early, they can sometimes have a more detrimental effect on your eyesight than the original uveitis.
Complications of uveitis may be caused by the inflammation inside the eye. However, they may also be caused by the steroid treatment used to control the inflammation. Despite this, as a rule, using enough steroids to control the uveitis will generally give a better outcome than using too few steroids and failing to control the inflammation. Complications that can sometimes occur with uveitis include:
- Formation Of Synechiae: synechiae are the name given to the bands of tissue that can form between the iris and the lens due to inflammation if uveitis is not promptly treated. Dilating eye drops can sometimes help to prevent synechiae.
- Glaucoma: the synechiae that form mean that fluid in the eye is not able to drain properly. This can lead to a build-up of pressure within your eye which can cause to glaucoma. If untreated, glaucoma can lead to visual loss. Glaucoma can also be a side-effect of long-term steroid treatment
- Macula Oedema: this is when fluid builds up in the back of your eye around your macula on your retina. Macula oedema can cause permanent visual loss.
- Cataract Formation: the inflammation can cause changes in the lens of your eye, causing cataract formation. Cataracts may also be caused as a side-effect from long-term steroid treatment. If a cataract worsens and is left untreated, it can lead to visual loss.
- Retinal Detachment: the inflammation can cause ‘pulling’ on your retina so that it ‘comes away’ or becomes detached. This can cause you to experience flashing lights, floaters and problems with your vision. If you think that you have a retinal detachment, contact your doctor immediately as urgent surgery is often needed.
Usually, the sooner treatment for anterior uveitis is started, the better the outlook and, more often than not, the quicker it goes away. However, anterior uveitis can recur, especially if it is associated with an underlying illness such as an autoimmune disease or inflammatory diseases as mentioned above. Anterior uveitis can also become chronic in some people, despite early and adequate treatment.
Intermediate or posterior uveitis is more likely to last for a long time or be chronic.
Though, some people who have recurrent uveitis learn to recognise their symptoms. They may be given additional steroid eye drops to keep in reserve to start when their usual symptoms reappear. People with chronic or recurrent uveitis are usually under the long-term care of an eye specialist and have regular check-ups in the outpatient clinic.
Uveitis caused by infection generally clears up when the infection is treated and does not recur.
Our Appointments Team have a dedicated and caring approach to finding you the earliest appointment possible with the best specialist.
If you do not have a GP, then we have an in-house private GP practice that you can use. Alternatively we can suggest the most appropriate course of action for you to take, given your location and individual circumstance.
If you have medical insurance (e.g. Bupa, Axa PPP, Norwich Union), you will need to contact your insurer to get authorisation for any treatment and, in most cases, you will require a referral letter from your GP.