Vessel disease in the eyes could signal heart disease, too

Does the eye betray what the heart is doing? When it comes to the health of this organ, it just might, says a study in the March issue of the journal Heart.

Researchers followed 199 people with diabetes and 2,768 without, all of whom were participating in Australia's Blue Mountains Eye Study for 12 years. The presence of retinopathy was assessed in retinal photographs, and reports of mortality associated with coronary heart disease were gathered from the country's National Death Index. Nearly 29% of those with diabetes and almost 10% of those without had evidence of this eye disease. Retinopathy increased the risk of death from a cardiovascular cause in those with diabetes by 121% and in those without by 33%.

"The retina is a unique site, where the condition of the microcirculation can be noninvasively viewed," wrote Jie Jin Wang, PhD, one of the authors and a senior research officer in the University of Sydney's ophthalmology department, in an e-mail. "We assume that the changes we see in the retina ... may occur in the small vessel system ... of the heart, the brain and elsewhere."

The fact that retinopathy can be caused by diabetes and is a marker of cardiovascular health in this population is well-documented, and regular eye exams are part of routine care for these patients. Still, this study is one of the first to find that the eye may be a "mirror of systematic health" for all, says an accompanying editorial.

This study and others "open a whole new field of risk-factor assessment for some major systematic diseases," wrote Dr. Paul J. Foster, PhD, the editorial's lead author and a professor at the University College London's Institute of Ophthalmology, also by e-mail. "Techniques for imaging the eye and performing automated, quantitative grading of these images is rapidly improving. It is interesting to consider the future potential for automated examination of the eyes in assessing the risk of heart disease and other major systemic disease."

Study authors suggest that retinopathy might become a part of cardiovascular disease risk assessment, because it is independent of other factors currently used. Physicians praised the study for showing that signs of retinopathy could be important in the general population.

"Retinopathy is not only a window. It's also a canary in the coal mine in showing the earliest signs of problems," said JoAnn E. Manson, MD, DrPH, chief of preventive medicine at Brigham and Women's Hospital in Boston. She also is a professor of medicine at Harvard Medical School.

Physicians expressed caution, though, about attempting to get more eye exams for patients. The information gleaned probably won't change already common advice for a healthier diet and more exercise. Access to comprehensive eye exams also may be challenging.

"[This study] certainly makes sense, and it raises some very interesting possibilities. The eye is a good place to see what might be going on elsewhere," said Tillman Farley, MD, a family physician and medical director of the Salud Family Health Centers in Fort Lupton, Colo.

"But I don't know that looking for retinopathy is going to change my recommendations to people, and we cannot even get a lot of diabetics in for retinopathy screening," he added.

Also, these researchers used fundus photography, which is not widely available in the primary care setting. The tools that are commonly used by primary care physicians to examine the eye miss about half of all retinopathy cases.

"This [study] is another excellent example of the importance of a complete ophthalmologic examination in the management of patients with systemic disease. But the question is, how do we translate this into clinical practice?" asked George A. Williams, MD, an American Academy of Ophthalmology trustee and chair of ophthalmology at Beaumont Hospital in Royal Oak, Mich. "We need a better way to accurately image the retina in patients outside of the ophthalmologist's office. Most ophthalmologists have this technology, but we're not managing heart disease."

In addition, experts wondered what it meant about heart health when patients didn't have signs of retinopathy. Some also expressed an interest in investigating retinopathy evaluation as a noninvasive alternative to assessing the possibility of heart disease in patients who present with chest pain.