Retinitis pigmentosa (RP) is an eye disease that can cause serious vision loss, and it is usually inherited. Its symptoms can begin at any age and include reduced peripheral vision (tunnel vision), night blindness, difficulty adapting to changes in light levels, and eventually, blindness. RP is a type of retinal dystrophy that results in progressive degeneration of rod photoreceptor cells. While this disease is degenerative, much can be done to reduce or delay its effects.
How Retinitis Pigmentosa Is Diagnosed
Any changes in vision should be reported to an eye doctor immediately. Initially, RP patients may notice gradual changes in peripheral vision — the vision to the sides, top and bottom of the field of vision. Any symptoms of night blindness should also be reported.
The doctor will typically perform visual field tests and visual acuity tests. He or she will utilize fundus and optical coherence imagery. Also, a special eye test called electroretinography (ERG) is used to detect abnormal function in the cells of the retina. This is done painlessly using numbing drops and utilizes an electrode on a contact lens-type device. It can detect RP before symptoms appear.
Retinitis pigmentosa has genetic links, so a complete family history of eye disease is part of how RP is diagnosed. Of the RP that is not due to another disease, many genetic connections have been found.
In its latter stages, RP causes bone spicule accumulation in the eye’s retina. Photographing the fundus (retina) during pupil dilation can verify which stage of RP the patient is in.
Causes
RP is caused by rod and cone photoreceptor or retinal pigment epithelium mutations or abnormalities in the retina. These problems are typically due to genetic defects, often inherited from one or both parents. Retinitis pigmentosa can be a symptom of the genetic disease “Usher Syndrome,” which also includes damage to hearing and balance.
In 1989-1990, scientists discovered the first mutation that causes RP. Rhodopsin is a pigment in the eye essential to seeing in low light. A mutation in the gene that produces rhodopsin was identified in some RP patients. Since this time, 100+ RHO mutations have been found, accounting for a quarter of autosomal dominant types of RP (meaning, only one parent has to have the mutation for RP for it to possibly manifest in their child).1
Genes control the pigment in photoreceptor cells. In the rods, these protein-based molecules are called rhodopsin, and in the cones, they are called iodopsin. Mutations, which are typically inherited, can cause deposits of bone “spicules” to appear on the retina or make the photoreceptors break down. Mutations in the rhodopsin gene are estimated to cause a quarter or more of photoreceptor defects.
Prognosis
The only good news about retinitis pigmentosa is that it typically does not result in total blindness. However, there is no specific cure for RP, and it is inevitably progressive. Visual acuity and visual field will deteriorate over time. Research into potential treatments is underway. Hope lies in preventing further vision loss and restoring sight.
Genetic counseling before symptoms occur can prepare a likely retinitis pigmentosa patient for the issue of progressive vision loss; however, the most important are the age at which symptoms start and how quickly the photoreceptors degrade. Vision therapy from low vision specialists and corrective visual aids can help with symptoms. Getting access to support groups and ensuring medical care is available (such as having vision insurance) also help.
The eyes are a reflection of overall health in the body; therefore, even genetic diseases such as RP most likely can be mitigated by making good lifestyle and nutrition choices. See “Other Approaches to Retinitis Pigmentosa Support and Prevention” below.
Standard Treatment
Currently (2015) retinal photoreceptor mutations and dystrophy are categorized as incurable. Gene therapy may be developed in the future.
Other Approaches to Retinitis Pigmentosa Support and Prevention
Natural Eye Care has prepared a special Photoreceptor Support Page to provide background information and ideas for anyone with photoreceptor issues.
Vision loss may be moderated by diet and lifestyle choices. Here are some suggestions for general eye health from Natural Eye Care:
- Stay active. Regular exercise is the single most important way to protect your overall physical condition.
- Maintain an appropriate weight.
- Don’t smoke, and limit alcohol.
- Don’t take unnecessary medications. Show your doctor all your medicine bottles and ask how to optimize dosages and medications.
- Wear wraparound sunglasses with UVA & UVB protection.
- Eat plenty of organic fruits and vegetables.
- Limit your intake of refined sugar.
- Reduce or eliminate fried foods and fast food.
- Avoid hydrogenated oils and trans fats.
- Read labels and only eat foods with ingredients that you can pronounce.
- Take targeted eye nutrients such as vitamin A or beta carotene, lutein, bilberry, CoQ10 and gingko biloba or vinpocetine for example.
Did you know that Natural Eye Care offers free eye exercises to help remove toxins and relieve eye congestion? Click to get our eye exercises, which includes acupressure instructions.
One study found that a particular mix of fish oils & DHA slowed down vision loss from RP. Lutein was linked to improved vision in RP patients in a 2003 study and a 2006 RP study. Antioxidants may show promise for retinitis pigmentosa patients, according to animal studies (2006).