WHAT IS RETINITIS PIGMENTOSA?

RETINITIS PIGMENTOSA (RP) is a group of genetic disorders that affect the retina’s ability to respond to light. This inherited disease causes a slow loss of vision, beginning with decreased night vision and loss of peripheral (side) vision. Eventually, blindness results. Unfortunately, there is no cure for RP.
The retina is the layer of light-sensing cells lining the back of your eye that converts light rays into nerve impulses. The impulses are sent through the optic nerve to your brain, where they are recognized as images.
With RP, cells in the retina called rods and cones die. With most forms of RP, rods — which are mainly in the outer regions of the retina and are responsible for our peripheral and night vision — degenerate first. When the retina’s more centrally-located cones are affected, the result is loss of color perception and central (reading) vision.
Retinitis pigmentosa causes slow loss of vision. Symptoms begin with decreased night vision and later progress to loss of peripheral (side) vision — creating a “tunnel vision” effect. Some people may also have difficulty identifying colors. The rate of vision change varies in different people depending on the genetic makeup of their disorder.
As night vision decreases, the ability to adjust to darkness becomes more difficult. You may stumble over objects in the dark, find driving at dusk and night difficult and see poorly in dimly lit rooms, such as a movie theater. While your vision during the day may be completely normal, your inability to see in dark conditions is considered “night blindness.”
In some cases, central vision may be affected first, making detail work difficult, such as reading or threading a needle. This may be referred to as macular dystrophy, because the central area of the retina, called the macula, is affected.

RETINIS PIGMENTOSA TREATMENT:

Currently there is no known cure for retinitis pigmentosa. However, research has shown that vitamin A palmitate may slow the progression of certain forms of RP. Your ophthalmologist can advise you about the risks and benefits of vitamin A palmitate and how much you can safely take. Taking too much vitamin A palmitate can be toxic, and evidence of vitamin A palmitate’s effect on RP progression is not substantial.
Another recommendation for slowing vision loss from RP is to wear sunglasses to protect your retina from harmful ultraviolet (UV) light.
Retinitis pigmentosa research is being conducted in areas such as gene therapy and transplant options. Since RP is a genetically-based disease, gene therapy has become a widely explored area of research, particularly in identifying ways to insert healthy genes into the retina. And as hereditary causes for RP are discovered, researchers hope to develop treatments to prevent the progression of retinitis pigmentosa.

Op.Dr.Ahmet UMAY
Bristol University
Ophtalmology Section / United Kingdom

Resource : Eyesmart