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Home > About Retinis Pigmentosa

About Retinis Pigmentosa

Retinitis pigmentosa (RP) is a genetically linked disease and is the major cause of inherited blindness, affecting 1:4000 people in the Western world and as many as 1:400 in Southern India and parts of China. The disease is characterised by the progressive loss of photoreceptor cells and peripheral vision and is associated with night-vision difficulties.

RP can present at any age from childhood to the mid-50s but is most usually diagnosed in early adulthood. There is no known effective treatment for RP. For those affected, a bionic eye offers significant hope.

It is estimated that 285 million people are visually impaired worldwide; 39 million of whom are legally blind. Although uncorrected refractive errors are the main cause of visual impairment, diseases associated with degeneration of the retinal photoreceptors result in severe visual loss with few or no therapeutic options for ongoing clinical management.


How vision WORKS

When a human sees an object, the light travels from that object to the cornea, then passes through the aqueous humour, pupil, lens and vitreous humour to reach the retina. During this passage, the light becomes focused onto the macula.

At the macula, the light causes chemical reactions in the cone cells, that consequently send electrical messages from the eye to the brain. The brain recognises these messages and indicates to the person that a particular object has been seen. The cone cells are therefore responsible for being able to recognise colours and to read.

The rod cells are essential for a person to be able see in the dark, and to detect objects to the sides, above and below the object on which the person is directly focused. This function prevents the person from bumping into obstacles when moving around.

In RP it is the rods and cones which degenerate leading to loss of sight.