A Bold Pursuit of a Vision

The Klein Legacy After 40 Years

Drs. Ronald and Barbara Klein joined the University of Wisconsin School of Medicine and Public Health in the 1970s to pursue their interest in vision and ocular research. In particular, they were interested in diabetic retinopathy and common age related eye diseases. Their research approach was informed by their training in epidemiology and public health. Thus, they enrolled defined population-based samples of participants who were followed over many years in the studies that have come to be known as the Ocular Epidemiology Research Group (OERG).

The first of these studies was the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR). The original National Institutes of Health-National Eye Institute funding was for five years. Further questions arose from this phase of the study and the group was then successful in obtaining subsequent funding to continue and expand the findings from this study. Ultimately, the group successfully competed for funding for nearly 40 years with supplemental funding from the Retina Research Foundation. The thrust of the diabetes studies was to determine the frequency and severity of complications from type 1 and type 2 diabetes – including retinopathy, kidney diseases, vascular diseases, amputations and functional correlates of these conditions, as well as potential risk factors, such as glycemic control, blood pressure, reproductive factors and more. In addition, relationship of changes in health care practices to complications has been obtained. Data from the WESDR was important in the development of educational programs for patients, like the National Eye Health Education Program guidelines.

While the WESDR was actively accumulating information about diabetes, the Kleins began a different study focused on common age-related eye diseases in an American community–Beaver Dam, Wisconsin. Starting in 1988, the Beaver Dam Eye Study (BDES) examined approximately 5,000 persons from that community, and came back into the community for additional examinations every 5 years afterwards for the next 25 years. This study collected information on the prevalence and incidence of age-related cataract, age-related macular degeneration and diabetic retinopathy–all common eye diseases in an aging population. The study also examined other aging issues, such as overall health and frailty, quality of life and related environmental and medical exposures. Data from the BDES indicate that in people 75 years of age or older, the cumulative incidence of visual impairment after accounting for the competing risk of death is 25%, of which 4% is severe. This finding reveals a public health problem of considerable magnitude, as the US population in this age group is expected to increase by 55% from 18 million in the year 2005, to 28 million by the year 2025.

“The Kleins’ work directly measuring the prevalence and incidence of eye disease in the general population — both in Beaver Dam and other population-based studies — is foundational for understanding the burden of eye disease in the United States, and increasingly the global burden of eye disease. This information provides the basis for much of the world’s efforts to alleviate blindness”

John Kempen, MD, MPH, PhD, MHS, an international expert in vision science and ophthalmic epidemiology at Massachusetts Eye and Ear.

Although the Kleins’ legacy continues to contribute to the body of vision science and ultimately, to the future of vision health, their last NIH grant will end in 2019. The Ocular Epidemiology Research Group’s remaining members are moving on, however, the methods employed in the Kleins’ studies will endure as epidemiological and medical researchers worldwide have adapted them.

James Onofrey, long-time administrator for the Kleins’ grants, reflects on their audacious pursuit of a vision. “They had the confidence to seek NEI-NIH funding for this type of study and the moxie to convince entire communities to continue their participation across the years. They maintained a long-standing research team to recruit, examine and re-examine these populations for more than three decades. This type of work can only be taken on by the most unflappable and determined researchers,” says Onofrey. “Patients in ophthalmology, diabetes, cardiovascular and geriatrics care have benefited without knowing the contributions made by these two researchers and their team. Both patients and researchers in places as far flung as the Netherlands, Australia and Singapore have benefitted from, and been inspired by, the research conducted by the Kleins. The ophthalmology world and the University of Wisconsin in particular owe them a debt of gratitude.”