RP management aims at slowing down the degenerative process, providing low vision aids and psychological support. A number of drugs have been proposed for the management but the evidence supporting their effectiveness is variable and generally limited. Referral to a low vision specialist is very helpful.
- Patients should regularly visit an eye care specialist for examinations and treatment any ocular complications such as cataracts, glaucoma and cystoid macular edema.
- Patient should use sunglasses to protect the retina from ultraviolet light. Bright light can damage the epithelium.
- It is important to receive genetic consulting and have all the family members (siblings and offspring) examined for evidence of RP.
- General consulting by experienced staff is essential. It is worth mentioning that most children have enough sight to complete their education in normal schools.
- It is legally required that the RP patient must inform services responsible for providing driver License about his medical condition and do a specialised visual field test which is carried out by specially approved optometrists.
- The patient should make registration for severe sight impairment or for sight impairment.
What should I do if my child is diagnosed with RP?
If you child is diagnosed with RP, his or her case should be evaluated by a low vision specialist as soon as possible. School administration and teachers should also be warned of his or her medical condition. Nowadays there are a lot of low vision aids which help to maximize existing vision. For example, there are special lenses that magnify central vision to expand visual field and eliminate glare, computer programs, reading the text, portable lightning devices, adjusting a dark environment. It is also important to have regular eye examinations.
What is the extent of independence for people with advanced RP?
What can increase the quality of such people’s lives?
Nowadays there are quite a number of services helping people with RP to conduct their daily business of living: from transportation to housekeeping. Such services teach how to orientate and travel with a white cane or a dog guide, and inform about control of illumination and contrast, special lenses. With advancing technology many assistive devices appear, becoming more and more sophisticated and helpful for people with RP. They include closedcircuit televisions (CCTV), reading machines, different computer programs which allow to enlarge type on screen or provide braille version of what the screen shows.
Also there are optical devices which maximize the usable vision: eyeglasses, prisms, telescopes, and night vision aids, which can be useful way to scan surroundings and find the bearings.
Treatments for RP
Known facts about possible therapies for RP with drugs
With the exception of vitamin A palmitate, there are currently no drugs available to actually treat people with RP. But work by scientists around the country is beginning to lay the foundation for the development of pharmaceutical agents that one day might alleviate or prevent the symptoms of RP.
Several drugs treatments have been proposed to slow down progression of Retinitis pigmentosa. There are following treatment are know as hyperbaric oxygen delivery, topical brimonidine tartrate, vitamins, docosahexaenoic acid, gangliosides, lutein, oral nilvadipine, ciliary neurotrophic factor, and valproic acid. All treatments seems to be safe but did not show significant benefit on visual function. Although all medical treatments for RP appear safe, evidence of effectiveness is limited.
Important! Please note that:
- Never try on your own drug therapies as a self prescription.
- The decision to use any drugs should be discussed with your local eye specialist
- It is difficult to predict how anyone will respond to particular drugs and in certain conditions there is a risk of getting side effects.
About vitamin A
Some practitioners also consider vitamin A as a possible treatment option to slow down the progression of RP. Research suggests taking high doses of vitamin A (15,000 IU/day) may slow progression a little in some people, but the results are not strong enough. Taking too much vitamin A can be toxic and the effects of vitamin A on the disease is relatively weak. Talk to an eye care professional to determine if taking vitamin A is right for you or your child.
Gene therapy research
Since RP is usually the result of a defective gene, gene therapy has become a widely explored area for future research. The goal of such research would be to discover ways healthy genes can be inserted into the retina.
Gene therapy is based on simple logic: If a gene is defective, replace it with one that is not defective. While this may sound simple, the actual procedure of gene therapy is very complex. There are a number of reasons why RP is a disease particularly suited to the use of gene therapy. First and foremost, some of the defective genes have been identified. Also, there are a number of applicable animal models in which gene therapy can be tested for effectiveness and safety. While all of the above factors make gene therapy a promising future approach for treating RP, there are still many obstacles remaining. One key question is how to actually introduce the healthy gene into diseased cells. In laboratory experiments, researchers have found that a neutralized virus can transport a healthy gene to degenerating photoreceptor cells. This viral delivery method must be made safe and effective before gene therapy can be tested in humans.
Retinal cell transplantation
Retinal cell transplantation is a procedure that may have promise for people with RP in the future, although it is still in its early experimental stages. Scientists hope to restore sight or prevent further vision loss by transplanting healthy retinal cells. Retinal transplantation has shown some promise in animal models. As a result, researchers have begun testing the safety of this experimental therapy in humans. While promising, retinal cell transplants must first be proven safe and effective in clinical trials before they can be made available as a therapy for patients. Currently, the progress of transplant research is rapidly evolving. Attempts at transplanting healthy retinal cells into sick retinas are being made experimentally and have not yet been considered as clinically safe and successful.
Retinal prosthesis is also an important area of exploration because the prosthesis, a man-made device intended to replace a damaged body part, can be designed to take over the function of the lost photoreceptors.
An artificial vision device called the Argus II has also shown promise for restoring some vision to people with late-stage RP. The Argus II is a prosthetic device that functions in place of lost photoreceptor cells. It consists of a light-sensitive electrode that is surgically implanted on the retina. A pair of glasses with a camera wirelessly transmits signals to the electrode that are then relayed to the brain. Although it does not restore normal vision, in clinical studies, the Argus II enabled people with RP to read large letters and navigate environments without the use of a cane or guide dog. Argus II device has not proven effective, but the FDA has determined that its probable benefits outweigh its risks to health.
Novel researches dedicated to growth factors
Growth factors are a group of molecules. If they are introduced to a diseased retina, they might prevent or delay the degeneration of photoreceptor cells. Growth factors are small proteins that sustain cells or cause cells to multiply. When healthy cells are injured, growth factors go to work to repair cellular injury and prevent cell death. Scientists have demonstrated that several different growth factors can keep injured and dying photoreceptor cells alive in rats. They have even found that injecting the factor into the eye of a rat with an inherited retinal degeneration can delay the onset of the disease. There is a long way to go to determine important information about growth factors and other drugs regarding potential toxicity and appropriate dosages. But the interest in growth factors continues, and increasing support for this work from The Foundation Fighting Blindness as well as drug companies and the federal government, is helping to accelerate the pace of research into what could be a future treatment for retinal degenerations.
Non invasive therapeutic electrical stimulation of the retina
Therapeutic electrical stimulation is a relatively new technology developed in 90th and has been used clinically since 1991. It is a non invasive and non surgical way of natural restoration of visual functions done by applying weak currents around the eye. Stimulations are not aimed at the replacement of damaged cells, but are focused on an increase in the functionality of preserved neurons on the retina and on the enhancement activity of the visual system at all levels. Approximately 55% of all the RP patients experience increasing of seeing area (central area in 30 degree) in about two times. The other 45% of the patients demonstrate enlargement of VF size for 25-75% from initial level.
Besides VF loss, many RP patients have a lot of no less severe complaints such as night blindness, disturbed central vision, high light sensitivity combined with light glare and difficulties in adapting to environments with different illumination.