What is Retinitis Pigmentosa?
Retinitis Pigmentosa, also known as RP, is an inherited, genetic, eye disease, that causes retinal degeneration. This disease affects one in every four thousand people. RP causes the retina, which is the light-sensing cells in the back of the eye, to deteriorate. The result of this degeneration is the loss of peripheral vision, loss of central vision, night blindness, and sometimes blindness.
When light hits the retina, light-sensing cells called photoreceptors, transport the light to the brain through electrical impulses. The brain then sends the information back to the eyes and this is what is know as sight or vision. When someone has RP, the light-sensing cells have degenerated causing the connection to the brain to be lost.
Light-sensing cells in the retina are grouped into cones and rods. Cones, found on the inner layer of the retina, are what we use to see during the day, see colors, and help sharpen our vision. Rods, found in the outer layer of the retina, are what we use to see at night. Since the rods are on the outer layer of the retina, we use that for peripheral vision as well.
There are various forms of RP including, Usher syndrome, Leber congenital amaurosis, and Bardet-Biedl syndrome.
What are the symptoms of Retinitis Pigmentosa?
As noted above, the effect of RP on the eyes depends on whether there is a deterioration of the cones or the rods. In most cases, the rods are affected first and thus, there is night blindness and loss of peripheral vision. When the cones are affected, colors, visual acuity, and central vision are lost. Tunnel vision will also be developed.
RP is generally diagnosed in adolescents and is a progressive disease. By age 40, most RP patients are legally blind.
What treatments are there?
Unfortunately, RP is an incurable disease. Having the loss of night-vision, peripheral vision, or any other part of vision can be a very difficult and traumatic experience. There is a sense of loss of independence. One can’t drive, watch TV, see their family and friends normally, or do general household activities.
At our Downtown New York City Low Vision clinic, we offer a number of solutions to help the patient to be able to cope with this disease and begin to live a more normal life. We like to fit our patients with telescopic lenses or reversed telescopic lenses. The telescopes lenses are small telescopes that are placed on the lens and, just like a binocular, enlarge the objects in the vision path. However, the field of vision will be smaller. A reverse telescopic lens is just like holding binoculars backward. Objects will be smaller but field vision is greater, giving the patient a larger area of mobility because they see more of their surroundings.
There are also a number of magnifiers or readers that can be used to help magnify text so patients can read.
Recent research indicates that taking supplements of vitamin A may slow the progression of RP in adults. Consult with your eye doctor about whether this therapy is right for you or your child.
Also, a new artificial vision device called the Argus II has been able to restore vision to some people with late-stage RP. This prosthetic device works in place of lost photoreceptors. While it cannot fully restore normal vision, the Argus II can enable patients with RP to read large print and maneuver around without use of a guide dog or cane.
Gene therapy for retinitis pigmentosa is currently showing promise in laboratory studies as a way to prevent vision loss and regain eyesight. Presently, many scientific developments to treat retinitis pigmentosa are on the horizon.
Give us a call at 646-846-7741 so we can discuss the best solution for your or your loved one to help them regain their independence.