Rates of AMD Declining
January 20, 2011 - This month, American scientists reported some good news – fewer Americans over age 40 are showing signs of Age-Related Macular Degeneration (AMD).
The study examined the eyes of over 5500 Americans and compared the results to a similar large study done 15 years earlier. These examinations were able to detect AMD at the earliest stages. The researchers led by Dr. Ronald Klein, professor at the University of Wisconsin School of Medicine, showed that about 30% fewer Americans had signs of AMD.
The scientists speculate that this drop may reflect the declining numbers of smokers – a major risk factor for AMD. Improvements in diet, physical activity and blood pressure control could also contribute to the change.
In total, the study showed that 6.5% of Americans over the age of 40 have some signs of macular degeneration. Most of these individuals would have had few, if any, symptoms. Less than one percent of those over age 40 had late stage AMD.
Although a study like this has not been done in Canada, it is likely that Canadian patterns are similar. Click here for tips on AMD prevention from our AMD Information Centre.
A Note on Statistics
This story is a good example of the power of statistics to enlighten... and confuse.
The study explores the prevalence of AMD, the proportion of people in a certain age group that will develop AMD.
While the prevalence of AMD is dropping, the overall number of people with AMD is increasing. Why? Today there are more seniors living in North America then there were just a few years ago. In fact, the population of Canadian seniors has doubled since 1981 and is expected to double again by 2036.