What is retinitis pigmentosa?
Retinitis pigmentosa (RP) is a group of inherited problems of the retina. The retina is a thin layer of delicate nerve tissue that lines the inside wall of the eye like the film in a camera. In the eye, light is focused onto the retina, which “takes the picture” and sends the image to the brain. Retinitis pigmentosa especially affects the peripheral part of the retina where there are many rod-shaped cells that normally provide side vision and night vision. In advanced cases it may also affect the sharp, central, reading vision and color vision.
What causes retinitis pigmentosa?
Retinitis pigmentosa is inherited through a variety of different genes. Because it is hereditary, other members of the family may have retinitis pigmentosa. However, sometimes the symptoms are mild and special testing may be required. At other times the abnormal gene that causes retinitis pigmentosa may skip several generations. In these families no other members can be found to have the problem.
What are the symptoms of retinitis pigmentosa?
Retinitis pigmentosa may cause no symptoms in the early stages. And symptoms may begin early or late in life. Initially, night vision is impaired. This makes it difficult to walk in unfamiliar surroundings in dim illumination. When the peripheral vision (side vision) is affected, an individual with retinitis pigmentosa may accidentally bump into things that are not directly in view. The severity of these symptoms slowly progresses over years and may impair safe driving vision or result in legal blindness. The rate of progression tends to be consistent in each family affected. Therefore, older family members may be able to provide useful information to younger family members. Late in the course of retinitis pigmentosa, the central vision and color vision may be affected. Make a point to have trusted family and friends help to monitor your ability to drive safely and ask your doctor annually if you have sufficient vision to drive safely and legally.
How is retinitis pigmentosa diagnosed?
The symptoms listed above may be the first clue to the diagnosis. A routine dilated eye examination can detect the retinal changes of retinitis pigmentosa. In some cases, a fluorescein angiogram is helpful. In this procedure the ophthalmologist injects a dye into the vein of the arm. Special photographs are taken of the eye, which show the degeneration of the retina. An electroretinogram (ERG) is also used to demonstrate faint electrical abnormalities in retinal function. In this test, electrodes are taped to the head and to contact lenses. A computer magnifies the electrical impulses generated by the retina in response to carefully programmed flashing lights. Finally, genetic testing may be considered in order to identify a specific gene variant that may be responsible for causing the problem. This may be important in confirming the diagnosis, genetic counseling, and treatment. Blueprint genetics offers free testing for US residents.
How is retinitis pigmentosa treated?
There is currently no proven treatment for most forms of retinitis pigmentosa. One type of retinitis pigmentosa is caused by a gene called RPE65. Patients with this gene variant may undergo gene therapy to treat this type of retinitis pigmentosa. Future research offers the hope of treatment of additional genes that cause retinitis pigmentosa. A mouth swab may be sent for free gene testing.
What about vitamins and nutritional supplements?
For many years research indicated that high doses of vitamin A may be helpful to slow the progression of RP. However, in 2023 a carefully designed analysis revealed there is no benefit, in general. They did report a possible benefit in a rare type of RP seen in families with mutations in the RHO gene. High doses of vitamin A may cause liver damage and should be administered under the care of a physician.
Vitamin E appears to be harmful in high doses for people with RP. It appears to worsen the vision. Therefore, the AREDS vitamins that are recommended for people with age-related macular degeneration should be avoided in people with retinitis pigmentosa. However, routine use of multi-vitamins are safe in RP, as they usually contain less than 30 IU vitamin E per day.
There are other supplements that are often recommended. Lutein is often recommended in RP at a dose of 10-20 mg per day. Fish oil (DHA 200mg per day) may be a helpful antioxidant in RP. Much research needs to be done to prove they are helpful, but there is no compelling evidence to indicate that they are harmful.
Should patients with RP avoid sunlight?
There appears to be consensus among experts in the field, that sunlight tends to worsen the progression of retinitis pigmentosa. Therefore, most recommend avoiding excess exposure to sunlight. Wear a broad-brimmed hat and sunglasses when out-of-doors.
What support services are available?
A wide range of support services, rehabilitation programs, and devices are available to help people with retinitis pigmentosa continue with many of their favorite activities. The use of a white cane can be a valuable aid in navigating in unfamiliar surroundings. It also serves to notify other people to be more courteous. The Lighthouse for the Blind and the Watson Center have classes and specialists in providing prescription lenses to magnify printed material. The Argus II Retinal Implant was approved by the FDA in 2013 for patients with very severe loss of vision from retinitis pigmentosa. The Division of Blind Services provides rehabilitation services and financial aid for eye care in selected cases. Your doctor can give free access to the “talking book” library to make “books on tape” available. A form is available from your doctor that establishes legal blindness to be used for property tax and income tax deductions. As always, if you have any questions please do not hesitate to contact your doctor for more information.
For a telemedicine consultation with Dr Pautler, please send email request to spautler@rvaf.com. We accept Medicare and most insurances in Florida. Please include contact information (including phone number) in the email. We are unable to provide consultation for those living outside the state of Florida with the exception of limited one-time consultations with residents of the following states: Alabama, Arkansas, Connecticut, Georgia, Minnesota, and Washington.
Copyright © 2021-2024 Designs Unlimited of Florida. All Rights Reserved.