Birdshot Chorioretinopathy (also called Birdshot Uveitis) is a rare chronic disease in which the immune system attacks the sensitive sight-enabling structures at the back of the eye. The term ‘Uveitis’ describes a number of conditions which are characterised by inflammation within the eye, and which are further classified according to which part of the eye is affected: front (anterior uveitis), middle (intermediate uveitis), back (posterior uveitis) or all parts (panuveitis).  Birdshot Chorioretinopathy is a form of sight-threatening posterior uveitis which requires specialist treatment to prevent the inflammation causing irreversible damage to the retina (the light-sensitive layer which enables you to see) and the choroid (the major blood supply and support tissue to the retina).

What do patients with Birdshot Chorioretinopathy notice?

The first thing that most patients with Birdshot Chorioretinopathy and other forms of Posterior Uveitis will notice will be floaters and/or blurred vision caused by inflammatory cells in the vitreous (the ‘jelly’ in the eye). Floaters are very common, and of themselves may not be anything to worry about, but floaters with reduction of vision definitely do need specialist assessment by an ophthalmologist. These forms of uveitis are not painful, but can cause serious loss of vision and do need consideration of treatment.

Patients with Birdshot Chorioretinopathy report a range of symptoms. These may include:

• impaired vision in dim light (Nyctalopia)
• abnormal colour vision (Dyschromatopsia)
• sensitivity or discomfort to bright lights (Photophobia)
• a perception of flickering or flashing lights (Photopsia)
• shimmering vision (this is difficult to describe, but some people describe it as being like looking through glass or through water)
• distorted images (Metamorphopsia)
• decreased peripheral vision (peripheral vision is the ability to see on either side, whilst looking forward)

The name ‘Birdshot’ comes from the unusual appearance of the back of the eye of patients with longstanding Birdshot Chorioretinopathy. The appearance of a scattering of yellow-white oval flecks are said to resemble the spread of pellets fired from a shotgun.

What causes Birdshot Chorioretinopathy?

The cause of Birdshot is not known, but there is good evidence that it is an autoimmune disease (a condition in which the immune system incorrectly attacks healthy tissues in the body).  Importantly there appears to be a genetic susceptibility to this condition as the majority of people who are diagnosed with Birdshot Chorioretinopathy carry a gene which makes a cell-surface protein called HLA- A29. This type of protein is involved in the way the body’s immune system recognises its own cells but also recognises ‘danger’ such as bugs from outside. HLA-A29 cannot be the whole story as many people have this cell-surface marker and never get Birdshot Chorioretinopathy. Researchers - scientists, patients and doctors working together - are continuing to study these early events to try to work out what triggers Birdshot Chorioretinopathy, and how we can treat it better.

Information about the service

What can I expect?

In the Birdshot Chorioretinopathy clinic, we aim to provide a ‘one-stop’ clinic. When you arrive you will be met by a specialist nurse who will measure your vision, and ask you about any ways in which the condition (or its treatment) is affecting you. We often use questionnaires to help provide a more detailed assessment of the condition and its impact.

You will then have anaesthetic drops put in your eyes to allow us to measure the pressure and ‘dilating’ drops which enable us to see the back of the eye in more detail. A very important part of your assessment is to have specialist imaging to help assess whether the condition is still active or controlled, and to help guide your treatment. We have a range of world-class imaging devices which enable us to detect changes down to a few thousandths of a millimetre, all as easily as having a photograph taken.

How often will I come to the Birdshot Clinic at the Centre for Rare Diseases?

For local patients it is likely that all their clinic appointments – usually four per year - will be in the Birdshot Clinic at the Centre for Rare Diseases, but patients from further away are likely have their care shared between the Birdshot Clinic and their local eye specialist, with perhaps two review appointments per year in the ITM clinic.

How to contact the service

Jacqui Orpe – Medical Secretary

Email: Jacqui.Orpe@uhb.nhs.uk
Tel: 0121 371 6905