Please use these factsheets as background information to help discussion with your doctors. Individual cases may vary enormously and so the best information will always come from your doctors. The information in this sheet has been checked for accuracy by leading Uveitis Specialists.

If we think of the eye as a hollow, fluid-filled, 3-layered ball, then the outer layer is the sclera, a tough coat, the innermost is the retina, the thin light-gathering layer, and the middle layer is the Uvea. The Uvea is made up of the iris, the ciliary body and the choroid (see diagram). When any part of the uvea becomes inflammed then it is called Uveitis.

A big problem, for patients and doctors alike, is that there are many different types of Uveitis. This is because:

1. The Uvea is made up of different parts. So if the iris is affected, the condition and its treatment could be totally different to that if the blood vessels, say in the choroid part of the Uvea is affected.

2. The inflammation in the Uvea very often affects other parts of the eye such as the retina and so a variety of other problems can be present to complicate the picture.

3. Next there are a large number of medical conditions where Uveitis is a feature amongst the other symptoms of the disease. e.g. Behcet’s Syndrome, Sarcoidosis and Toxoplasmosis.

4.There are many different types of causes of Uveitis [see below under Causes].

All this means that we will hear lots of different names and descriptions. The term intraocular inflammation is now commonly used to describe the various types and it is important not to worry if you can’t get hold of one simple name to describe your condition. It is very important, however, for a correct diagnosis to be made [that is, what is going on in the eye? what is causing it? and is there any other disease or other part of the body affected?].

If it is suspected you have uveitis, then you will expect to be examined very thoroughly to see what type of uveitis you have and, importantly, to see if there is any evidence of any other underlying conditions [unless another condition is already known about]. This may involve a whole variety of tests like blood-tests, X-rays of your back, scans, etc.,all of which are straightforward enough and painless, but can take some time.

The eyes will obviously be thoroughly examined. This usually involves having some eye-drops to make the pupils wider so that the doctor can see into your eye more easily. The doctor will then look into your eyes using different optical instruments, all of which will just be like looking into a bright light.

You may also have a fluorescein angiogram, which means having a small amount of yellow dye injected into your arm, whilst some photos are taken of your eyes. Once again, all this is painless and just involves looking at bright lights and flashes. Because the drops used affect your eyesight for a short while afterwards, you will usually not be able to drive or read for a couple of hours after your appointment.

An important part of the examination will be the simple and familiar sight tests to measure your visual acuity, using a sight chart as you would find at the opticians.

Normal eyesight is 6\6. This means that the 2nd smallest row of letters can be seen 6 metres away. 6\60 means that you can see only the top letter and 3\60 means that you can only see the top letter from 3 metres.

Your near or reading vision is measured by seeing how small a print size you can manage. These are numbered, normal eyesight being N5 (this leaflet is N14 and newspaper print is normally

N 8). Try and ask what your measurements are when you are at the clinic and write them down somewhere. They will be useful when speaking to other people with similar problems and if you need to contact anyone like the RNIB for help with low vision aids etc. (see 'low vision' in pt. info section).

As suggested before, there are a large number of possible causes of Uveitis. It may result from:

•  an infection such as a virus (e.g. herpes) 

• a fungus (e.g. histoplasmosis). 

• It may be due to a parasite such as toxoplas

• It may be related to Autoimmune Disease (with or without involvement of other systemic disease).
• Trauma to the eye, or even the other eye in the past, can lead to Uveitis.
• In many cases the cause remains unknown.

There are too many separate conditions, that cause, or are linked with, Uveitis to list them all but as an Information Group we would aim to advise people on all the possible conditions, when asked.

Uveitis Information Group is a charity registered in Scotland, no. SCO28439