June 29, 2009

‘Nature’ and ‘nurture’ predictors of AMD

Gene variants, ocular and environmental factors, age, smoking, body mass index, contribute to developing age-related macular degeneration, U.S. researchers say.

Lead author Dr. Johanna M. Seddon, of Tufts University School of Medicine and director of the Ophthalmic Epidemiology and Genetics Service at Tufts Medical Center, said all of these factors were combined and used to develop a predictive and possibly diagnostic model.

More than 1,400 people in the Age-Related Eye Disease Study with an average follow-up time of 6.3 years were evaluated and genetic specimens were genotyped. Both prevalence and development of advanced dry and wet age-related macular degeneration over the course of the study were included in the analyses.

The researchers found all tested variables to be independently associated with age-related macular degeneration. The predictive power of the variables in the formula was very high, and the probability that the risk score based on the group of factors in that model for a progressor was higher than the corresponding risk score for a random non-progressor within the same 10 year age group was 83 percent.

The determinants of the model can be assessed by completing a questionnaire and taking a blood test, and it is a tool which could be used to help guide prevention and treatments, Seddon said in a statement.

The findings were published in the journal Investigative Ophthalmolgy & Visual Science.