The Cardio Connection: Heart Health Influences Ocular Diseases, Study Says

Exercise regularly, don’t smoke, and avoid high cholesterol foods—all tenets of optimal health that patients frequently receive from their primary care physician and other doctors. They’ll especially hear this refrain from their cardiologist, as these behaviors are commonly associated with a healthy heart. But patients may not be aware of the effect these lifestyles choices have on their vision as well. With cases of visual impairment in the United States set to double by 2050, ophthalmologists may want to consider adding this language to their work-ups as well.

A new study published in The American Journal of Medicine shows the connection between cardiovascular health and the prevalence of ocular diseases, such as glaucoma, cataract, age-related macular degeneration (AMD), and diabetic retinopathy (DR). The study used interviewer-administered questionnaires, physical examinations, and specimen collections to examine 6118 Americans (with an average age of 57). The investigators reported a “remarkable decrease in the odds” of these sight-threatening conditions with increasing levels of ideal cardiovascular health.

Specifically, the authors used the American Heart Association’s “Life’s Simple 7 (LS7)” metrics to show subjects’ odds of developing one of these ocular diseases. The LS7 quantifies an individual’s ideal cardiovascular health based on seven cardiovascular disease risk factors: smoking, physical activity, body mass index, diet, blood pressure, total cholesterol, and blood glucose. The study found that worsening L27 metrics are associated with greater instances of DR, even after being adjusted for age, sex, race, education, and income. Excusing those factors, researchers also found increased risk for AMD, cataract, and glaucoma. 

Younger, non-Hispanic, Caucasian females with education beyond high school, and who live above the poverty line had the most optimal cardiovascular health, according to the study. Other demographic groups varied across levels of cardiovascular health and ocular disease. Notably, 55% of participants with AMD also had inadequate cardiovascular health, the research shows. Additionally, 84% of participants who had  DR also had inadequate cardiovascular health.

The researchers say the associations they found indicate that patients with cardiovascular diseases require increased screening to identify potential ocular diseases, in particular DR .¹  The link between DR and heart disease was the most stark in this study, and the report offered insight into that specific connection. Heart disease can reduce the flow of blood, leading to hypoxia and oxidative stress.¹ This oxidative stress is what can lead to the development of retinopathy.¹ “Additionally, oxidative stress is also known to cause resistance of diabetic retinopathy to reverse after good glycemic control is reinstituted” the authors explain. “This is likely because of the accumulation of damaged molecules and reactive oxidative species that are not easily removed even after the reestablishment of good glycemic control.”

The same interventions that aim to prevent cardiovascular disease could potentially prevent ocular diseases because of the profound overlap in risk factors. The study also suggests more opportunity for collaboration between cardiologists and ophthalmologists. With more overlap in care, increased screenings for critical cardiovascular and ocular diseases can lead to a higher quality of life for patients. 

The authors did offer a glimmer of hope, saying their findings “suggest that interventions to prevent cardiovascular diseases hold promise in preventing ocular diseases.”

Reference

De La Cruz N, Shabaneh O, Appiah D. The Association of Ideal Cardiovascular Health and Ocular Diseases Among US Adults.Published online August 19, 2020.  Am J Med. doi: https://doi.org/10.1016/j.amjmed.2020.06.004. 

This article originally appeared on Ophthalmology Advisor