Retinitis pigmentosa

What is it?

Retinitis pigmentosa is a group of inherited eye diseases that damage the retina. The retina has two kinds of light-sensing cells: rods, for seeing in dim light, and cones, for daylight and colour. In this disease they are slowly lost, usually the rods first. Both eyes are usually affected.

It is the most common inherited disease of the retina, affecting about 1 in 3,500 to 4,000 people in the United States and Europe. Having family members with it is the main risk. Retinitis pigmentosa can have different inheritance patterns depending on the specific gene involved. It can be autosomal dominant (one altered copy of a gene is enough, and most people have an affected parent), autosomal recessive (both copies of a gene must have a variant; the parents each carry one copy), or X-linked (in males one altered copy is typically sufficient; this is not always true for females).

The first signs

Symptoms often first appear in childhood, but severe vision problems do not often develop before early adulthood.

• poor night vision, or trouble finding your way in the dark;
• losing side vision, so it feels like looking through a tunnel;
• sensitivity to bright light;
• later, trouble seeing colours and reading.

How doctors find out

Tests include an exam of the retina by ophthalmoscopy after the pupils have been dilated. The main sign of the disease is the presence of dark deposits in the retina. Other tests check your side vision, sharpness of sight and colour vision, take photos of the retina, and measure the retina's electrical response to light (electroretinogram).

Current treatment

There is no effective treatment for this condition. Sunglasses that protect the retina from ultraviolet light may help preserve vision, a vision specialist can help you adapt to vision loss, and cataracts or retinal swelling found at regular eye checks can be treated.

Will it get worse?

Yes, slowly. The age it starts and how fast it gets worse differ from person to person. Over time, both side and central vision are lost, which makes reading, driving and recognising faces harder. Most people with it become legally blind as adults, but complete blindness is uncommon.

Medicines and supplements: what helps, and what to watch for

There is no effective treatment for this condition.

Good to know:

• sunglasses that block ultraviolet light may help protect the sight you have;
• some studies suggest that treatment with antioxidants (such as high doses of vitamin A palmitate) may slow the disease, but taking high doses of vitamin A can cause serious liver problems, and the benefit of treatment must be weighed against the risks to the liver;
• make regular visits to an eye care specialist, who can detect cataracts or retinal swelling; both of these problems can be treated.

Eye surgery, for some people

People with RP often develop cataracts at an early age. Cataracts can be removed if they contribute to vision loss. Tiny electronic implants for the retina are still at an early stage of development.

Is there a cure?

There is no effective treatment for this condition. Clinical trials are testing gene therapy and supplements such as omega-3 (DHA) and lutein.

See the 76 trials you can join

Sources

Written in plain words by Frontlight from these pages:

1. MedlinePlus: Retinitis pigmentosa
2. MedlinePlus Genetics: Retinitis pigmentosa