About Retinitis Pigmentosa
Below you will find general information about the eye disease Retinitis Pigmentosa. If you have any questions, feel free to ask in a comment below.
Please Note: The majority of the following information was provided by these websites:
Foundation Fighting Blindness
http://www.lowvision.org/retinitis_pigmentosa.htm
http://www.visionchannel.net/retinitis
http://en.wikipedia.org/wiki/Retinitis_pigmentosa
Retinitis Pigmentosa (RP) is a term that refers to a group of inherited retinal diseases in which abnormalities of the rod and cone cells (photoreceptors) lead to progressive visual loss. (Rod cells help us see images in our peripheral or side vision, and in dark and dimly lit environments. Cone cells allow us to see fine visual detail in the center of our vision, and also allow us to perceive color.)
Most forms of RP first cause the degeneration of rod cells, which produces night blindness. Night blindness is somewhat like the experience normally sighted individuals encounter when entering a dark movie theatre on a bright, sunny day. However, people with RP are unable to adjust well to dark and dimly lit environments.
As the disease progresses and more rod cells degenerate, patients lose their peripheral vision in addition to their night vision. RP patients often experience a ring of vision loss in their mid-periphery, but maintain vision centrally and in their far periphery. This leads to a sensation of tunnel vision, as though they see the world through a straw. (Imagine holding up a donut a few inches from your face. You can see through the center and outside of it, but the donut blocks the middle area.) Progressive loss of the visual field is the hallmark of RP.
As their vision deteriorates, some RP patients see rapid flashes of light in their eyes. The flashes are caused by the dead/dieing rods as they attempt to send electrical impulses. (My flashes float and swirl across my visual field. There is no rhyme or reason to when the flashes appear. Sometimes they appear several times a minute, other times they will not appear for hours.)
RP patients often also experience a low tolerance to bright lights and light glares. When they go into bright sunlight, they are often overwhelmed by white-out debilitating glare. Depending on the patient, it may take several minutes for their eyes to adjust to the new lighting.
Symptoms of RP usually manifest between the ages of 10 and 30, with progression of the disease continuing throughout the individuals life. Severity and speed of vision loss vary with each patient (no two cases are alike), but the majority of people with RP are legally blind by the time they are 40 or 50 years old.
Legally blind individuals are those whose best visual sharpness or acuity (with glasses or contact lenses, if needed) is 20/200 or worse in their better eye; or whose visual field, regardless of acuity, is restricted to a 20 degree diameter (10 degree radius). Many patients with RP retain a small degree of central vision throughout their life, but the loss of their periphery vision categorizes them as legally blind.
It is estimated that anywhere from 50,000 to 400,000 people in the United States have RP, and approximately 1.5 million people are afflicted by it worldwide. Retinitis Pigmentosa affects all people of all races in all nations. It does not discriminate.
There is currently no cure or medical treatment for Retinitis Pigmentosa. However, scientists continue to investigate possible treatments including retinal transplants, artificial retinal implants, gene therapy, stem cells, nutritional supplements, and/or drug therapies.
