The end of vision loss because of aging is within sight.
A simple blood test can determine whether or not a person is likely to develop Age-Related Macular Degeneration, a common form of irreversible vision loss.
AMD is a disorder in the eye in which a portion of the retina known as the macula degenerates. The macula is crucial for clear and central vision in eyesight.
People who contract AMD have a difficult time reading, watching television and seeing faces, even if they are near. Legal blindness is often what the disease leads to, especially in patients who are older than 60.
The contributing factor of age-related blindness was discovered in a gene by researchers at the John A. Moran Eye Center at the U.
The study was led by Kang Zhang, director of the division of ophthalmic genetics at the Moran Eye Center and associate professor of ophthalmology and visual sciences at the U.
"We conducted the study because of the knowledge we had of the major gene contributing to AMD," Zhang said. "There were many studies which pointed to it, but the lab discovered the actual gene, which is a major contributor."
The study focused on the genetics of people who had the disease versus those who didn't to identify the mutant gene that causes AMD.
Within the study, 581 people who had AMD were genotyped, along with 309 people who didn't, and were compared genetically. The study demonstrated that if a person had a mutant copy of a certain gene, he or she had an increased risk of developing AMD.
Researchers in the U lab looked for single nucleotide polymorphisms within people's genotypes that have AMD to find similar genetic mutations.
What they found were changes in areas of the gene, which can be used to identify a patient's risk of developing it, said Zhang.
The blood test determines whether a person who carries the mutant gene is likely to develop AMD. It allows for people who test positive for the mutant gene to adapt their diets and lifestyles to lower their risk of contracting it or delaying its onset.
The research conducted by Zhang has also identified a genetic pathway of AMD, allowing for new drugs to be produced aimed at treating it within this specific pathway, which could lead to more effective ways of treating the disease.
"I hope that this research will focus the scientific community on the gene related to AMD; and secondly, that it will benefit the patient to help those who have it," said Joshua Cameron, a U graduate student in neuroscience and one of the senior authors of the paper released by the study. "This disease is debilitating for millions of Americans and people around the world."
Additional research by departments at the U, such as the Eccles Institute of Human Genetics, as well as several other institutions worldwide contributed to the study, which was published online in the journal Science on Oct. 19.
