Macular degeneration is one of the most common causes of vision loss in adults age 50 and older, yet there often are no symptoms in its earliest stages. But now there is strong evidence that if you have another common disease of aging that it’s time to get your eyes checked—immediately. The new research also provides a more clear-eyed view of the path to preventing this vision thief.
WHAT YOUR HEART HAS TO SAY ABOUT YOUR EYES
Researchers have long suspected that there’s a link between heart disease and age-related macular degeneration (AMD). The two diseases share many risk factors beyond simply age—smoking, high blood pressure, high blood cholesterol levels, diabetes and obesity. But research attempting to connect the dots between these risk factors and the two diseases has been inconsistent. One study found an association with stroke but not coronary heart disease, while another found an association with coronary heart disease but not stroke.
A new study from “down under” used a more powerful measure than risk factors—clinical evidence of the extent and severity of coronary heart disease. The Australian researchers carefully studied the eyes of men and women with suspected heart disease who were already scheduled to have an angiogram. The results have implications both for early diagnosis and prevention of AMD.
EARLY SIGNS OF A LEADING CAUSE OF BLINDNESS
While the more than 1,600 subjects ranged in age from 23 to 92, the average age of those who had coronary heart disease was just over 60. By contrast, the late stage of macular degeneration that actually causes vision symptoms (problems with ability to see fine detail, reading and driving and eventually even seeing faces) often doesn’t occur until people reach their late 70s or early 80s. Early macular degeneration, and often the intermediate stage, has no symptoms, although it can be detected by a comprehensive eye exam. By the time that vision is impaired, it’s harder to treat.
The men and women in the study all had coronary angiography, a procedure in which dye injected into a catheter shows how blood flows through the arteries to the heart. The angiograms allowed cardiologists to take precise measurements to grade the severity of blockage in the coronary arteries. Severity was quantified two ways—first by the number of vessels with significant obstruction, and then by using a Gensini score, a more sophisticated calculation that places emphasis on the more important artery segments. The participants also had their eyes checked out very carefully for signs of AMD.
Results: About 6% of the men and women had early AMD and 1.4% had late AMD. Those who had serious artery blockage were much more likely to have early AMD. After adjusting for age, gender, body mass index, smoking, diabetes and other risk factors, the participants with a narrowing of more than 50% in any one artery segment were nearly twice as likely to have early AMD compared with participants without artery narrowing. Those with narrowing in all three main coronary arteries were 2.7 times more likely to have early AMD. The Gensini score was also highly associated with early AMD—participants with the highest Gensini scores were more than twice as likely as those with the lowest scores to have early AMD.
There were some differences between men and women, too, another indication that heart disease affects the genders differently. For women, there was no link between artery blockage and early AMD, but those with the highest Gensini score were five times more likely to have early AMD. More research is needed to understand how coronary artery disease affects the genders differently and how this relates to early AMD risk, the researchers conclude. But clearly there was risk for both genders.
A CLEAR AND PRESENT DANGER
The take-away messages from this study couldn’t be clearer…
• If you or someone you know has coronary heart disease, don’t wait to get your eyes checked. According to the Agency for Healthcare Research and Quality, all adults with no risk factors should have a comprehensive eye exam (which includes AMD testing) every five to 10 years. Those aged 40 to 54 may need to have it repeated only every two to four years…aged 55 to 64, every one to three years…those 65 and over, every one to two years. That’s fine for the general population, but this study suggests that people with heart disease should be checked immediately—and ask their doctor how often they should get rechecked.
• Go to your optometrist, ophthalmologist or retina specialist for a comprehensive eye exam. While many (not all) optometrists do screen for signs of AMD, opthamologists, (including those who are retina specialists) generally have much more sophisticated equipment. So you may be referred to one if an eye exam finds something suspicious. Opticians generally don’t screen for AMD.
• There’s no cure for this sight-robbing disease, but the process can be slowed down with a heart-healthy lifestyle and supplements, and it needs to be monitored so that when it does need treatment in the late stage, that starts right away.
• If you have both conditions, make sure your cardiologist and your eye specialist both know all of the medications and supplements you are taking. Blood thinners—prescription medications as well as aspirin and fish oil, for example—may cause bleeding problems, including in your eyes, that could make vision problems worse.
The new research also reinforces that a healthy lifestyle is important for the prevention of a wide variety of age-related diseases. Preventing macular degeneration is about more than just taking the right vitamins. According to the American Academy of Ophthamology, other eye diseases that are related to cardiovascular health include cataracts and retinopathy, often found in people with diabetes. Take care of your heart and you may be taking care of your eyes, too.