It is well known that certain diseases, such as diabetes can lead to glaucoma and exposure from high energy visible light (also known as blue light) can damage the macular pigment in the eye. What many don’t know is that some ethnic groups are at higher risk of vision conditions, regardless of exposure to difference wavelengths of light or the presence or absence of certain diseases.
A study done at the University of Texas Heath School of Public Health found 36 percent of Hispanic families in the U.S. that have a common form of retinitis pigmentosa (which is passed down through families) developed the disease because they carry a mutation of the arrestin-1 gene.
Arrestin-1 is a dominant gene since only one mutation is needed for retinitis pigmentosa. Other genes that cause retinitis pigmentosa are recessive, which means two gene mutations are needed to cause the disease. When the study’s senior author Stephen Daiger, Ph.D. first started researching retinitis pigmentosa in the 1980s, he and others were looking for the “one” gene that causes the disease. As it turns out, over 70 genes are linked to retinitis pigmentosa and while there isn’t a cure, treatments being developed that have shown promise in slowing the progress of the disease.
Of course, retinitis pigmentosa isn’t the only eye disease linked to an ethnic group. Another study was done at the University of Southern California Roski Eye Institute and this study found that Chinese-Americans have higher rates of “wet” age related macular degeneration than Caucasians and other ethnic groups in the U.S. They also had higher rates than Chinese persons living in either rural or urban areas of China. This suggests the combination of environmental and behavioral factors might be at work.
These studies underscore the importance of regular eye exams, since many of these conditions don’t present with any symptoms in the early stages. While there is no cure for retinitis pigmentosa or macular degeneration, there are treatments that can slow the progression of these diseases. These treatments work best during the early stages.
Clinical trials are also very important. There are studies being done on ways to treat and hopefully cure these diseases. One such treatment was recently approved by the Food and Drug Administration. The treatment is a form of genetic therapy for retinal diseases caused by a mutation in the RPE65 gene. This gene is responsible for blindness from Leber’s congenital amaurosis and some forms of retinitis pigmentosa. The clinical trials for this treatment improved vision for 13 out of the 20 patients in the trial. These patients were able to navigate mazes in low to medium levels of light, show improvement in light perception, and they had better peripheral vision.
While being a member of a certain ethnic group doesn’t mean that a person will automatically develop retinitis pigmentosa or macular degeneration, it is still important to be aware of what could happen based on your genetic background. That knowledge, coupled with regular eye exams and the practicing of a healthy lifestyle, can help to preserve vision.