About the Beaver Dam Eye Study

The Beaver Dam Eye Study is funded by the National Eye Institute, one of the 20 National Institutes of Health. The purpose of the Study is to collect information on the prevalence and incidence of age-related cataract, macular degeneration and diabetic retinopathy, which are all common eye diseases causing loss of vision in an aging population. The study was designed to discover (or detect) causes of these conditions. The study also has examined other aging problems, such as decline in overall health and quality of life and development of kidney and heart disease.

The study was initially funded in 1987. A private census was conducted in the city and township of Beaver Dam, Wisconsin, and found that there were approximately 6000 people aged 43 through 84 years. Approximately 5000 of them participated in the baseline examination between 1988 and 1990. Five-, 10-, 15-, and 20-year follow-up examinations have taken place and 3700, 2800, 2100, 2000, and more than 1900 people participated in each of the respective examination phases.So far there have been more than 300 publications describing the prevalence and incidence of visual loss, age-related macular degeneration, cataract, and associated risk factors as a result of this study. An important finding from the study is the association of cigarette smoking with both cataract and age-related macular degeneration. Another important finding is the description of the relationship of early abnormalities such as retinal drusen and increased and decreased retinal pigment with the progression to late stages of age-related macular degeneration. This information has been used to provide estimates of these conditions in the general population, to develop protocols, and to provide estimates on the number of participants needed to conduct large clinical trials on age-related macular degeneration.

Systems were developed to image (photograph) parts of the eye involved in cataract and age-related macular degeneration. A standard scale was developed in the Beaver Dam Eye Study to describe the severity of these abnormalities. The imaging systems and standard scale developed by the Beaver Dam Eye Study have been used in other epidemiological studies of these eye diseases including, the Blue Mountains Eye Study in Australia, the Rotterdam Study in the Netherlands, and the Los Angeles Latino Eye Study. These studies have also adapted protocols developed by the Beaver Dam Eye Study. Comparisons of the data from the Beaver Dam, Blue Mountains, and Rotterdam studies showed that despite a number of differences in exposures among the populations, the prevalence of late stages of age-related macular degeneration were similar. The strong association of cigarette smoking and macular degeneration was found in all three populations.

The Beaver Dam Eye Study completed its 20-year follow-up at the end of 2010. The purposes of the follow-up were to observe the long-term course of cataract, macular degeneration, diabetic retinopathy, other retinal diseases, and to monitor the decline in vision as the Eye Study participants age. We examined the relationship of long-term exposures (e.g., blood pressure, lipid levels, exposure to UV-light, and medications) to these eye conditions. We are measuring the effect of these eye conditions on function, quality of life, and future needs for medical counseling and rehabilitative services. This follow-up will provide needed information on the long-term evolution of age-related eye conditions. It will also enable us to better understand risk factors for eye conditions that will explain why some people contract these conditions and others are protected.