Retinitis pigmentosa (RP) is an inherited eye disorder that causes damage to the retina. At this time there is no cure for this disease; however, there are some treatments that help slow the disease. There is a great deal of research in progress at this time.
1. Stem Cell Research Advances
Research being conducted at the Gavin Herbert Eye Institute of the University of Irvine has been successful at proving it is possible to replace damaged rods and cones of the retina with photoreceptor progenitor stem cells from immature retinas. They are working to standardize a method to transfer the stem cells as this procedure will replace rods and rejuvenate cones, which will restore vision.
The California Institute for Regenerative Method reviewers scored the procedure a 98 out of a possible 100 as applicant for grants to continue research. This funding will make clinical trials a possibility within three years.
2. Gene Therapy has been Successful in Curing PR in Dogs
The research team at the University of Pennsylvania has proven they can prevent or reverse retinitis pigmentosa in dogs. The defects in the dogs with this genetic disease are identical to that of people. There are similarities between dogs and humans in their eye anatomy, disease characteristics, physiology and their response to gene therapy. It took more than 10 years of collaboration between clinicians to achieve these results.
This study used a combination of surgical techniques and genetic tools to assure the therapy targets just the diseased cells. The procedure uses a viral vector to target rods and cones. Then, a healthy RPGRgene acts as a promoter, which is a piece of genetic code that switches on the gene if the viral vector penetrates the correct damaged cell. This is obviously a complicated procedure to understand, but scientist are optimistic about its curative value for retinitis pigmentosa.
3. Hyperbaric Oxygen Chamber
Hyperbaric oxygen therapy has been shown to help preserve the patient’s visual acuity and the visual field. It also preserves the ERG response. The ERG is a recording of the electrical currents produced in the retina in response to a light stimulus. The hyperbaric oxygen therapy was shown to preserve the vision over a ten year study. One consideration with HBOT is that it has shown to accelerate cataracts in some cases.
3. Argus II Retinal Prosthesis
The U.S. Food and Drug Administration have approved the Argus II retinal prosthesis, also known as the “bionic retina.” This is a device that took 20 years to develop by Second Sight Medical Products, Inc. Argus II is designed for patients who have severe vision loss or are completely blind. The patients have a surgically implanted electrode that bypasses the photoreceptor cells. A miniature camera is mounted on glasses that connects to a video processing unit that is worn on the patient’s belt.
It does not completely restore vision, but it does allow the person to see images and distinguish better between light and dark. This helps patients perform their basic tasks more easily. It will only help approximately 4,000 people, but certainly those 4,000 people have an improved quality of life.
There are several clinical studies in various stages throughout the world to find a cure of retinitis pigmentosa. They do not yet have the technology to actually transplant an eye, due to the intricacies of the brain-eye connection. Scientists believe they will have a cure during the next few years for this disorder.