What is Retinitis Pigmentosa?
Retinitis Pigmentosa (R.P.) is one of a group of inherited visual disorders that causes the degeneration of the retina of the eyes. Vision gradually decreases and may eventually be lost. R.P. can be associated with deafness and other malfunctions, central nervous system and metabolic disorders, and chromosomal abnormalities.
How does it progress?
Most cases of Retinitis Pigmentosa take a long time to develop and vision loss is gradual. Signs usually appear during childhood or adolescence, beginning with night blindness followed by a slow loss of peripheral vision. The disease will cause further loss of side vision and eventually, people with R.P. may often bump into chairs and other objects as their vision becomes limited to one direction. They can only see straight ahead, as if in a tunnel, which gives the disease its common term tunnel vision.
Why does it occur?
Not much is known about the cause of Retinitis Pigmentosa, except that it is inherited. Sometimes the disease is genetically dominant, meaning only one gene needs to come from a parent for the child to have Retinitis Pigmentosa. Other times the disease is X-linked, meaning that only one gene passed from the mother will cause the child to develop the disease.
Is there a cure?
While there is no cure for R.P., research indicates that vitamin A and lutein may slow the rate at which the disease progresses. Occupational therapy is a good idea before too much vision is lost since it may be easier to learn how to work around vision loss while vision is still available.
Scientists have been experimenting with ways to treat R.P. including implanting computer chips in people's eyes to see if electrical stimulation of the retina improves vision for people diagnosed with Retinitis Pigmentosa and age-related macular degeneration. However, this research is still in its preliminary stages and should take a few more years before results and treatment become available.
Another possible treatment is the drug Diltiazem (Cardizem, Tiazac). Used more commonly to treat high-blood pressure and angina. Diltiazem has delayed blindness in mice that have a condition resembling Retinitis Pigmentosa. Again there are several years of clinical trials ahead before we know if this is a viable treatment.
Individuals with reduced vision can use vision aids, develop a support network, and receive counseling and training to help them cope with their reduced vision and maintain their quality of life as much as possible.