Retinitis pigmentosa Dr Trisha Macnair Retinitis pigmentosa (RP) is the name given to a group of hereditary diseases of the retina - the light-sensitive tissue in the back of the eye. About 25,000 families in the UK are affected.

In this article

What's the cause? What are the symptoms?

What's the treatment? Advice and support

Dozens of different gene mutations that may lead to RP have been described. The condition, and the type, results from inheriting one or two of these abnormal genes.

Of those who inherit the disease, the milder forms are usually autosomal dominant, but RP inheritance can also be autosomal recessive or X-linked. However, nearly half of those with RP have no family history at all.

Some people have non-genetic RP. This may be induced by a viral infection, but most cases are new mutations.

The retina slowly degenerates and gradually loses its ability to transmit images to the brain, resulting in a progressive loss of vision. Cells from the pigmented layer of the retina migrate into the layer containing nerve cells, causing the typical pattern of black or brown star shapes in the retina that gives the diseases their name.

Symptoms usually become apparent between the ages of ten and 30, although some forms can develop much earlier or much later.

Visual loss may be slow or rapid. Often the first symptom is night blindness, followed by a narrowing of peripheral vision that leads to tunnel vision.

In one type of RP the loss of vision begins in the central area (macular dystrophy), interfering with reading and detailed work. There may be associated syndromes such as Usher syndrome.

There's no cure for retinitis pigmentosa and there are no treatments that stop the visual degeneration. However, good support and visual aids can help people cope with the condition.

Because of the huge number of faulty genes that can cause RP, many of which aren't yet fully identified, screening isn't straightforward. However, antenatal diagnosis is possible in some cases where there's a risk of X-linked and autosomal dominant RP.

British Retinitis Pigmentosa Society
Helpline: 0845 123 2354
Website: helpline@brps.org.uk
Website: www.brps.org.uk

This article was last medically reviewed by Dr Rob Hicks in July 2006.