Retinitis Pigmentosa (RP) refers to a group of inherited retinal diseases that cause progressive deterioration of the light-sensing cells in the retina, leading to significant visual impairment and blindness. There are many forms of RP and related diseases, including Usher syndrome, Leber Congenital Amaurosis, and Bardet-Biedl syndrome. Symptoms and progression can vary from person to person, as there are many different gene mutations known to cause RP. The Foundation Fighting Blindness (FFB) reports 100,000 people in the United States to have RP, making it one of the most common inherited retinal diseases (IRDs).
Hallmarks of RP
This eye condition can begin in childhood or adulthood. The first symptoms are usually trouble seeing at night and in low light, trouble adapting to changes in lighting, problems with glare, and light sensitivity. Photoreceptor cells from the outer periphery of the retina (rods) slowly die off. As RP progresses, the field of vision shrinks from its outside edges inward, causing loss of peripheral vision or tunnel vision and night blindness. In later stages, color perception and visual acuity can also be affected as cone cells near the retina’s center begin to die. In advanced stages, the visual field constricts until a tiny area of central vision remains, which can be blurry, and in some cases, all vision is lost.
The Genetics of Inherited Retinal Diseases
Many inherited retinal diseases have similar symptoms, which makes diagnosis challenging. Family history can help solve the puzzle, but genetic testing has become the benchmark for identifying these rare diseases. Approximately 270 known gene variants cause IRDs, and about 60 known gene variants cause RP that only affects the eyes. Nearly 50% of people with retinitis pigmentosa do not know their previous family history. Researchers believe there are more gene variants to identify. So, gene testing does not always lead to a precise diagnosis – sometimes, “variants of unspecified significance” may result. As gene testing technologies improve, more gene mutations will be identified.
Why Consider Genetic Testing?
Genetic testing can provide answers about your eye disease, empowering you to plan for your future. It can help you understand the progression and the inheritance pattern of your IRD. Your gene test results can help researchers identify new gene variants and accelerate the discovery of treatments. Identifying your gene variant may enable you to participate in research studies and clinical trials for emerging treatments. Learn more at EyesonGenes.com and find a testing guide to help you discuss genetic testing with your doctor and start the process.
How You Can Help
The Foundation Fighting Blindness (FFB) developed the My Retina Tracker® Registry, a research database of individuals and families affected by IRDs. The registry is a place to share valuable information about the 20 retinal diseases FFB studies and identify people who may want to participate in research studies and clinical trials. To learn more, visit My Retina Tracker Registry or contact [email protected] if you have trouble signing up for the registry. Membership registration is free. In addition, free open-access genetic testing is available through The No-Cost My Retina Tracker® Genetic Testing Program, sponsored by the Foundation Fighting Blindness and Blueprint Genetics. To learn more, visit: Open Access Genetic Testing Program — Foundation Fighting Blindness.
There is No Cure, But There is Hope
Scientists are making significant advances toward understanding RP and other IRDs and identifying the gene mutations causing them. The most promising areas of research that may lead to a cure one day are:
Artificial Vision Devices – Retinal ganglion cells, which transmit electrical signals to the brain, survive degenerative conditions, making artificial vision possible. This has led researchers to develop retinal prosthetic devices intended to provide electrical stimulation of the retina to induce visual perception in individuals with RP. Tiny microelectrodes can be implanted at the back of the eyeball to create electric pulses and stimulate ganglion cells to transmit visual signals to the brain again. Several retinal prostheses have come to market, such as the Argus II®. Still, there are problems with considerable variations in performance across patients for unknown reasons, and this situation prevents the broad use of these devices. The Korea Institute of Science and Technology research team continues to work on improving these devices.
“Our results suggest that it is crucial to carefully select candidate patients of retinal implants by thorough examinations assessing the progression level of each patient’s retinal degeneration,” said lead author Dr. Maesoon Im. “We are studying hardware and software approaches for the improved quality of artificial vision for patients with late-stage degeneration.” Medical Xpress, August 10, 2020
Gene Therapy – Disease-causing genes have sequence errors, additions, deletions, or substitutions in the instructional data. Gene therapy research techniques include replacing mutated genes with new normal copies of that gene, gene editing to correct the mistake in the gene, and RNA editing. Scientists have successfully used gene therapy to treat Leber Congenital Amaurosis (LCA) by correcting the error on the RPE65 gene, a groundbreaking accomplishment.
There are many active preclinical and clinical trials worldwide working to find a cure for retinal diseases. Explore the latest FDA-approved clinical trials. The Health Library at Vista Center, an affiliate of the Stanford Hospital Health Library also provides a retina research update newsletter upon request. Just email: [email protected] or learn more at wwwvistacenter.org.
Genetic testing is an essential step toward possible future treatments. Following clinical trials is a great way to stay informed and hopeful. Day to day, you can do more to improve your life with RP.
Living with Retinitis Pigmentosa
- Learn all you can about your eye condition and life with low vision, access technologies, and services that can help you adjust to RP.
- See a retinal specialist who has knowledge and experience with IRDs. FFB has a list of recommended doctors on its website.
- Join communities of others living with IRDs where you can find support. FFB, Facebook, low vision agencies, and some eye doctors offer support groups.
- Use the VisionAware national directory to find low-vision services in your area. Explore the website for helpful information about living with vision loss. Be sure to check out the APH ConnectCenter for educational webinars. Visit APH FamilyConnect if you are a parent of a child with RP and APH CareerConnect if you have vision loss and are seeking resources to help gain or maintain employment.
APH VisionAware is here to support you on your RP journey so you can live your best life.