About Ocular Epidemiology

Under the leadership of Professors Ronald and Barbara Klein, MD MPH, the Ocular Epidemiology Research Group has conducted studies in ophthalmic epidemiology and related fields since 1979. The group has conducted major ongoing projects such as the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) and the Beaver Dam Eye Study (BDES), and has collectively published over 600 papers. Particular areas of focus include diabetic retinopathy, other diabetic complications, age-related macular degeneration, cataract, retinal vasculature signs and their relationship to ocular systemic disease, and genetic studies.

Ron and Barbara KleinThe Wisconsin Epidemiologic Study of Diabetic Retinopathy began in 1979. One of the purposes of the WESDR is to describe the frequency and incidence of complications associated with diabetes (i.e., diabetic retinopathy and visual loss, diabetic nephropathy, and lower limb amputations). Another purpose is to identify risk factors (i.e., poor glycemic control, smoking, and high blood pressure) which may contribute to the development of diabetic complications. Additionally, the WESDR is designed to examine health care delivery for people with diabetes.

The WESDR is in the process of beginning a new phase of studies.  In prior phases examinations were done in a large 40-foot mobile examining van in an eleven-county area in southern Wisconsin and involved all persons with younger-onset type 1 diabetes (996 people) and a stratified sample of older-onset persons mostly with type 2 diabetes (1370 people) who were first examined between 1980 and 1982. The examinations were completed near participants' residences. The van provided standardized conditions to examine participants and minimize participants' travel time.

Many reports have been issued and continue to be issued from the WESDR, and these data have also been used in developing educational programs such as the National Eye Health Education Program's diabetes management guidelines for eye care. Follow-up examinations have continued over the past three decades.

The Beaver Dam Eye Study is a population-based study located in a small city in Wisconsin. The purpose of the study is to collect information on the prevalence and incidence of age-related cataract, age-related macular degeneration, and diabetic retinopathy, which are all common eye diseases in an aging population. The study has also examined other aging issues, such as overall health, quality of life, and environmental and medicinal exposures. Related studies have examined hearing and other sensory disabilities among this population.

The Beaver Dam Eye Study was initially funded in 1987. A private census was conducted and the study population of approximately 6,000 people aged 43 through 84 years living in the city and township of Beaver Dam, Wisconsin were identified. To date, there have been over 300 publications describing the prevalence and incidence of visual loss, age-related macular degeneration, and cataract and associated risk factors. Follow-up examinations have continued and are based at facilities in the Beaver Dam Community Hospital.

The WESDR and the Beaver Dam Eye Study are funded and supported by the National Eye Institute, part of the National Institutes of Health.

The Ocular Epidemiology group also provides retinal photo grading support to major national and international studies such as the Atherosclerosis Risk in Communities (ARIC) study, the Multi-Ethnic Study of Atherosclerosis (MESA) and the National Health and Nutrition Examination Survey (NHANES). It has researched the relationship between aging and macular degeneration, and related gender-specific issues. Overall findings have included the suggestion of a relation between hormone replacement therapy and age-related macular degeneration (AMD), and elucidation of possible genetic factors for AMD and cataracts. The methods deployed in these studies have been adapted by epidemiological and medical researchers worldwide.