Adapted from EurekAlert and the Journal of the American Medical Association
Variations of two common genes are associated with progression to more advanced forms of age-related macular degeneration, and factors such as smoking and being overweight greatly increase this risk, according to a study in the April 25, 2007 issue of the Journal of the American Medical Association (JAMA).
Age-related macular degeneration (AMD) occurs when the center of the inner lining of the eye suffers thinning, atrophy, and in some cases bleeding. This can lead to visual impairment and legal blindness, and is associated with variations in the CFH and LOC387715 genes. It is believed that no previous studies have examined the relationships between common variations in these genes and progression from early or intermediate stages of macular disease to advanced forms of AMD associated with visual loss, according to background information in the article.
Johanna M. Seddon, M.D., Sc.M., of Tufts-New England Medical Center, Boston, and colleagues assessed whether certain genetic variants have prognostic importance for progression to advanced AMD and related visual loss. The study included 1,466 white participants in the Age-Related Eye Disease Study (AREDS), a U.S. multicenter clinical trial conducted from 1990 to 2001 with an average follow-up time of 6.3 years.
The researchers found that the genetic variations of the CFH and LOC387715 genes were associated with progression to more advanced AMD after controlling for other factors associated with AMD, such as smoking.
The authors of the study say that it is premature at this time to consider genetic testing of individuals with various stages of AMD. However, in the future, a risk profile that includes genetic and environmental factors, may lead to targeted screening and closer monitoring of individuals who are at higher risk of visual loss due to AMD progression.
Macular Degeneration Research, a program of the American Health Assistance Foundation is proud to have previously funded Dr. Seddon for her work concerning biological factors related to age-related macular degeneration.