Tufts Medical Center Researchers Create A New Predictive Model For Age-related Macular Degeneration (AMD)

Main Category: Eye Health / Blindness
Also Included In: Genetics;  Clinical Trials / Drug Trials
Article Date: 24 Apr 2009 - 4:00 PDT

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Researchers at Tufts Medical Center have created a formula for predicting how likely it is that individuals with certain genetic profiles and lifestyle behaviors will develop advanced Age-related Macular Degeneration (AMD), a potentially blinding condition that currently affects an estimated two million older Americans and is increasing dramatically as the population ages.

The study, led by Johanna M. Seddon, MD, ScM, Professor of Ophthalmology at Tufts University School of Medicine and Director of the Ophthalmic Epidemiology and Genetics Service at Tufts Medical Center, evaluated six genotypes that either increase or decrease risk for AMD. In addition to age, sex, and education, she also incorporated smoking status and higher body mass index (BMI) which increase risk of AMD, and supplementation with a high-dose formulation of antioxidants and zinc which delays progression of the disease. Using their new algorithm, Dr. Seddon and her colleagues determined that several genotypes plus the lifestyle factors can predict progression to the advanced forms of AMD with a certainty as high as 83%. The paper, "Prediction model for prevalence and incidence of advanced age-related macular degeneration based on genetic, demographic, and environmental variables" was published in the May issue of the journal Investigative Ophthalmology & Visual Science.

Their research also shows that although AMD has a strong genetic component, healthy behaviors can modify your genetic susceptibility. For example, among individuals with one genotype, the homozygous C3 risk genotype, the likelihood of progression to the advanced form of AMD increased from about three-fold for nonsmokers to nearly 10-fold for smokers.

"Our algorithm could help with the selection of study participants for treatment trials and could one day enable doctors to choose the most efficacious treatment for individual patients," Dr. Seddon said. "It also gives any older person concerned about AMD, or any patient with early stages or a family history of AMD, even more incentive to avoid risk factors such as smoking and excessive weight."

The study included 1,446 individuals from the Age-Related Eye Disease Study who had 6.3 years of follow-up, of which 279 progressed to the advanced stages of AMD.

About Tufts Medical Center

Tufts Medical Center is a not-for-profit, 439-bed academic medical center that is home to both a full-service hospital for adults and Floating Hospital for Children.

Source: Tufts Medical Center