Retinal degenerative diseases are a family of disorders that cause degeneration of the retina.
Retinitis pigmentosa (RP) is the name given to a group of inherited eye diseases that affect the retina. Retinitis pigmentosa causes the degeneration of photoreceptor cells in the retina. Photoreceptor cells capture and process light helping us to see. As these cells degenerate and die, patients experience progressive vision loss.
There are types of photoreceptor cells: rod cells and cone cells. Rod cells are concentrated along the outer perimeter of the retina. Rod cells help us to see images that come into our peripheral or side vision. They also help us to see in dark and dimly lit environments. Cone cells are concentrated in the macula, the center of the retina, and allow us to see fine visual detail in the center of our vision. Cone cells also allow us to perceive color. Together, rods and cones are the cells responsible for converting light into electrical impulses that are transmitted to the brain where "seeing" actually occurs.
Retinitis Pigmentosa is a genetic disorder. It is programmed into your cells, not caused by injury, infection or any other external agent. Genetic defects (mutations) send faulty messages to the retinal cells which leads to their progressive degeneration, which in turn, leads to vision loss.
Because Retinitis Pigmentosa is an inherited disorder, it is strongly recommended that if someone in your family is diagnosed with a retinal degenerative disease that all members of the family contact a retinal specialist.
Possibly, however, if you experience either of the symptoms noted above and your ophthalmologist isn't certain, you should consult with a retinal specialist. The Foundation maintains a list of doctors who specialize in retinal degenerative diseases.
Acuity Tests: This test measures the accuracy of your central vision at specific distances in specific lighting situations.
Color Testing: This can help determine the status of your cone cells, the retinal cells that interpret color.
Visual Field Test: This test uses a machine to measure how much peripheral vision you have.
Dark Adaptation Test: This test will measure how well your eyes adjust to changes in lighting and can help the doctor better understand the current function of your rod cells, which are the retinal cells responsible for night vision.
ERG Test: The ERG (electrophysiological test) records the electrical currents produced by the retina due to a light stimulus. The intensity and speed of the electrical signal becomes reduced as the photoreceptor cells degenerate.
The FFB maintains a list of retinal specialists. All of the eye care professionals on this referral list have indicated their interest in treating people with inherited retinal degenerative diseases. For a copy of the list for your home state, please contact The Foundation at 1-800-683-5555.
It's different for every patient.
A majority of people with RP are legally blind by the age of 40. 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).
A daily dose of 15,000 I.U. of Vitamin A can moderately slow the progression of RP. There are also several areas of research that offer tremendous promise for halting the disease or restoring vision loss:
For additional information on these or any other areas of our research, please scroll back to the Home Page or to the Master RP Page.
Input from the National Eye Institute