Aniridia

What is it?

Aniridia is a very rare eye condition in which the coloured part of the eye (the iris) does not fully develop and there are other associated eye problems. It affects 2 in every 100,000 people.

Most people with aniridia also have an under-developed fovea, which is a dip in the centre of the macula – the part of the light-sensitive layer of the eye (the retina) that we use for detailed, colour vision.

Later in life, people with aniridia may develop other eye problems such as glaucoma, cataract and 'corneal opacification', where the usually clear front surface of the eye (the cornea) becomes cloudy. The lens in the eye is often cloudy, too.

  • Causes

    Around 2 out of 3 people with aniridia inherit a faulty version of the gene PAX6 that has been passed down through the family. About 1 in 3 people have no family history of aniridia but develop a fault with PAX6 in the womb. In a few cases (about 2 out of every 100 people with the condition), aniridia is linked to the inherited disorder known as Gillespie syndrome, that affects balance, movement and mental ability.

  • Symptoms

    Soon after birth (at around 6 weeks old) people with aniridia will likely have involuntary eye movements (nystagmus). Trouble focusing (refractive error) and eyes that point in different directions (strabismus) are also common. People with aniridia may also have drooping eyelids (ptosis).

    The main threats to sight in people with aniridia come from glaucoma and also from the lens and cornea becoming cloudy, reducing the amount of light that reaches the retina. Vision may be hazy or blurred and the field of view may become more narrow over time. The cornea may be painful.

  • Treatments

    Treatment for aniridia can include eye drops to reduce high pressure in the eye and prevent glaucoma from getting worse. It may also include a corneal transplant to reconstruct the front of the eye. Any cataract in the eye may need to be removed and replaced with an artificial lens made of plastic.

  • Research

    Although we know the gene that causes aniridia, we still don’t understand exactly how the gene leads to disease and there are no specific treatments available yet. An important line of research is to find out why stem cells on the surface of the cornea stop working over time. It may be possible to develop a cell therapy that can keep the cornea clear.

    Read our research projects
  • Clinical trials

    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.

    Taking part

    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 Dr Sajjad Ahmad, University of Liverpool

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