Epidemiology a Major Focus of a New National Academies Report

The recently released report Making Eye Health a Population Health Imperative: Vision for Tomorrow¹ from the National Academies of Sciences, Engineering and Medicine (NASEM), written by the Committee on Public Health Approaches to Reduce Vision Impairment and Promote Eye Health, makes nine recommendations for improving eye and vision health, beginning with a call for a national goal to eliminate preventable vision impairment by 2030. As is typical of National Academies’ reports, sound epidemiologic studies enabled the Committee to make strong recommendations, though important gaps in our knowledge remain.

The socio-ecologic model that is widely used in population health lays out a broad framework for understanding the determinants of vision loss, as well as the opportunities for prevention, treatment, and maintenance of function. Although many of the underlying determinants of health—education, poverty, discrimination, health literacy, and the built and natural environments—are well established, specific studies linking them to vision loss were sparse. The consequences of not fully understanding the relationship between the underlying determinants of health and the epidemiology of vision loss and their impact on eye and vision health are significant. In addition to separating the eye and vision care system from much of health care, the siloing of eye and vision care within the health care system has diminished attention placed on the importance of the social and physical environments as central determinants of eye and vision health.

Many of the greatest accomplishments in eye and vision health are preventive. Diseases, such as trachoma, are now rare in the United States. Occupational eye injuries have been markedly reduced by implementation and enforcement of Occupational Safety and Health Administration standards. Yet too many people incur infections from improper care of contact lenses and still suffer eye injuries that could have been prevented by protective equipment—equipment that should be just as standard and normal as the use of seat belts, bicycle helmets and protective sports equipment.

Prevention of eye conditions begins with an understanding of risk factors, yet the Committee found a very mixed picture regarding the impact of common risk factors, such as obesity, physical activity, and tobacco, on eye conditions. Studies to quantify the impact of eye-specific risk factors such as screen time, ultraviolet light exposure, and long periods of close work and interventions to mitigate them are sorely needed to enable effective health information messages to be developed and delivered to the population.

In addition to the upstream issues, inadequate access to care contributes to disparities, yet the literature on health services research on eye care is surprisingly sparse. Studies to improve systems of eye and vision care and better integration with the medical care system and community resources are needed. Many rural areas, for example, have poor access to eye care providers and for patients, such as persons with diabetes, who need to see multiple providers, the challenges of multiple trips to medical centers are barriers to care. Model systems that deliver integrated services to these areas could enhance eye care and improve delivery of other services. Almost all states have requirements for vision screening or examination of pre-school children, yet few have systems in place to assure that those children who are detected actually are assured of the follow up and treatment they need. For those with uncorrectable vision loss, access to vision rehabilitation and reasonable accommodations can improve or maintain quality of life and the ability to perform activities of daily living. However, research on the benefits and cost-effectiveness of vision rehabilitation is very limited, thereby constraining awareness of treatment options for providers to consider and creating missed opportunities for improving health outcomes.

A major challenge for public health is the absence of robust research that would support a set of consistent, evidence-based guidelines, particularly for people who are asymptomatic. Indeed, optometric and ophthalmologic recommendations differ substantially in critical instances. Applying contemporary clinical epidemiologic standards, such as those used by the US Preventive Services Task Force, would greatly facilitate the uniformity of developing recommendations and its subsequent messaging to effect changes in attitudes, knowledge, behavior, and practices. A single set of clinical practice guidelines could not only form the basis for an educational campaign, but unified guidelines could also advise value-driven payment policies related to eye examinations, corrective lenses, assistive devices, and rehabilitation services.

Recent efforts to build an effective surveillance system are a step in the right direction, but important challenges remain. Most basically, a set of standardized definitions, terminology, questions, and metrics would reduce the confusion caused by the interpretation of words whose meaning could change depending on which surveillance system is used. Clinical registries will provide much deeper data resources for understanding eye conditions, but are no substitute for population-based epidemiological studies that assess both self-report and examination-based measures and include everyone in a geographic area, not just those receiving care. A national eye and vision health surveillance system (that includes a combination of all of the above-mentioned approaches) would comprehensively assess the total burden of eye disease and vision impairment including temporal trends—along with risk factors, comorbidities, at-risk populations, and care utilization—and inform decisions about public policy and the prioritization of resources, which in turn would contribute significantly to a population approach to reducing vision impairment and promoting eye health.

The Committee’s recommendations identified several key areas including public health surveillance, research (preventive research, health services research, population health services research, and biomedical research), and evidence-based guideline development with a focus on those areas where there is the greatest opportunity for improvements in population health. Long-term underinvestment in these areas by funders, such as NIH in basic biology and genetics rather than supporting fundamental epidemiologic research into the primary drivers of vision loss, contributes to the challenge of developing programs and activities that can effectively prevent vision impairment, including 8–16 million people with uncorrected refractive error and over 1 million with untreated cataracts. Epidemiology provides the foundation for any population-based approach—it is central to progress in all of the key areas identified by the Committee and warrants greater investment. By focusing their energies on the socio-ecologic etiologies of eye and vision morbidities that affect the greatest number of people over the longest time span, we will make great strides towards eliminating preventable causes of vision loss, improving population eye and vision health, and increasing health equity.

Declaration of interest

The authors were members of the NASEM Committee which wrote the report. No financial support was received for the writing of this article.