What is it?
Birdshot is a rare condition that is hard to treat and may lead to blindness. It affects the choroid and retina. The retina is the light-sensitive layer of the eye, and the choroid is a layer of blood vessels that supplies the retina.
Birdshot is also known as ‘Birdshot uveitis’ because the choroid is the back part of the inner lining of the eye (the uvea). The word uveitis means inflammation in the uvea.
Birdshot is thought to be what's known as an auto-immune disorder. This means that the body's defence system for fighting infection (the immune system) starts to attack parts of its own body.
Most people with Birdshot test positive for HLA-A29 - one particular version of a gene that's important for the immune system. But not everyone who tests positive will develop Birdshot, so there must be other factors that put people at risk. Almost everyone with Birdshot is white, and most are female and aged 40-60.
The main symptoms of Birdshot are reduced vision, seeing floaters, night blindness, problems with colour vision, glare and seeing flashes of light.
About 2 in 10 people with Birdshot have symptoms that get better on their own without treatment. But the condition may flare up again repeatedly.
There are several options for treatment if it's needed, but everyone responds differently and what works for one person may not work for someone else.
Treatment usually begins with steroids, taken by mouth, to reduce inflammation and suppress the immune system. Extra medication to suppress the immune system may also be needed.
Vitamin D and calcium supplements may be given to help with the side effects of taking high doses of steroids, which include weakening of the bones (osteoporosis). Other side effects of steroids can include bruised skin and stomach irritation. Side-effects in the eye include cataract (when the lens in the eye turns from clear to cloudy). Cataract can be treated with surgery to replace the cloudy lens with an artificial one.
In the long term, treatment may involve newer medications (known as biologics) that target specific parts of the immune system. These may be given by injection or drip. Sometimes a combination of treatments works better than one type of drug alone.
Birdshot research aims to learn more about exactly what goes wrong with the immune system and what makes some people more at risk of sight loss than others. At the moment, it’s hard to know when treatment should begin as everyone is so different.
Current treatments can stop working after a while and so it's vital to develop new treatments that work better, for more people, with fewer unwanted side effects.Read our research projects
You could play an important part in eye research by being a participant in clinical research study that may benefit many people. You could even help shape clinical research by becoming more actively involved and having a say. Patients, carer, or anyone with an interest can help.
What are clinical trials
Clinical trials are research studies that find out if a medical strategy, treatment, or device is safe and effective for humans. They are a key research tool for improving medical knowledge and patient care. The people who carry out research are mostly the same doctors and healthcare professionals who treat people. Their aim is to find better ways of treating patients and keeping people healthy.
Here are some ways to find out about research projects and clinical trials that you can get involved in.
UK Clinical Trials Gateway
The UK Clinical Trials Gateway run by the National Institute for Health Research (NIHR) provides easy to understand information about clinical research trials running in the UK, and gives to a large range of information about these trials. It is designed to enable patients and clinicians to locate and contact trials of interest. Visit their website and select the eye condition that you are interested in.
NIHR Clinical Research Network Portfolio
The NIHR Clinical Research Network Portfolio is a database of high-quality clinical research studies in England, Northern Ireland, Scotland and Wales. Within this the Ophthalmology Specialty Group supports a national portfolio of research studies in ophthalmology and the vision sciences. See their website for details.
If you wish to join a trial it is always best to discuss this with your doctor or clinical team first.
Last updated August 2015
Approved by Professor Robert MacLaren, Nuffield Laboratory of Ophthalmology, University of Oxford