An inherited progressive degeneration in the retina, the light-sensitive membrane at the back of the eye
- Most commonly begins between the ages of 10 and 30.
- Slightly more common in males
- Due to an abnormal gene inherited from one or both parents
- Lifestyle is not a significant factor
Retinitis pigmentosa is a rare disorder in which the cells in the light-sensitive retina in the eye are progressively lost. Dark patches of pigment form on the retina, and vision deteriorates. The disorder is slightly more common in males and symptoms usually first appear between the age of 10 and 30, although they may sometimes appear earlier or not until middle age. Retinitis pigmentosa may be inherited in an autosomal dominant, autosomal recessive, or sex-linked manner (see Gene disorders), depending on the abnormal gene involved. Both eyes are affected equally, although there is a large variation in the severity of the condition from one person to another.
If you have retinitis pigmentosa, the first symptom you may notice is poor vision in dim light. Later, the outer edges of vision, known as peripheral vision, are lost, and sight deteriorates progressively inwards until only a small area of central vision remains (this is known as tunnel vision). Rarely, tunnel vision can cause blindness. Retinitis pigmentosa is diagnosed by examining the retina with an ophthalmoscope (see Ophthalmoscopy). Although there is currently no treatment for retinitis pigmentosa, special glasses may help to widen the field of vision if you have tunnel vision. If you plan to have children, you may wish to have genetic counselling.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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