Patients with a specific form of age-related macular degeneration (AMD), a leading cause of blindness in the United States, are more likely to have underlying heart damage from heart failure and heart attacks, advanced heart valve disease, or carotid artery disease associated with types of Certain strokes, according to a new study from New York Eye and Ear Hospital at Mount Sinai.
This research was published on November 17 in BMJ Open Ophthalmology, is the first to identify the types of cardiovascular disease and high-risk carotid artery disease associated with this eye disorder. The findings could lead to increased screening to preserve vision, diagnose undetected heart disease, and prevent adverse cardiovascular events.
“For the first time, we were able to link these high-risk CVDs to a specific type of AMD, the type that has subretinal drosinoid deposits,” explains lead author R.S. Ophthalmology at the Icahn School of Medicine at Mount Sinai. “This study is the first strong link between the leading cause of blindness, AMD, and heart disease, the leading cause of death worldwide. Moreover, we also have strong evidence of what is actually going on: decreased blood flow to the eye is directly caused by these diseases, Either from damage to the heart that reduces blood flow throughout the body, or from a blocked carotid artery that directly impedes blood flow to the eye. Destroyed retinas and leftover SDDs are those damages. Retinal damage means loss of vision, and can lead to blindness.”
AMD is the leading cause of visual impairment and blindness in people over the age of 65 and is caused by damage to the central area of the retina called the macula, which is responsible for reading and driving vision. One early form of AMD consists of small yellow cholesterol deposits called drusen, which form under a part of the retina called the retinal pigment epithelium (RPE). The retina can be deprived of blood and oxygen, leading to vision loss. Drusen formation can be slowed down by appropriate vitamin supplementation. The other major form of early AMD, subretinal tuberous deposits (SDDs), are less well known, and require high-tech retinal imaging to detect them. These deposits contain a different form of cholesterol, and form above the RPE, just below the photosensitive cells of the retina, where damage occurs and vision is lost. There is no known cure for SDDs. Dr. Smith and a team of researchers at Mount Sinai first found that patients who had had cardiovascular disease or stroke were more likely to develop cardiovascular disease. This research, the first of its kind, was published in the July issue of Retina. This new study expands on this previous work, looking in a larger number of patients, and identifies specific severe forms of heart disease and carotid artery disease that cause SDDs of AMD.
The researchers analyzed the eyes of 200 AMD patients with retinal imaging to identify which patients had SDDs. The patients answered a questionnaire about their history of cardiovascular disease. Of the 200 patients, 97 had SDDs and 103 had BDs only. Of the 200 patients, 47 had severe heart disease (19 had heart damage due to heart failure or a heart attack, 17 had serious valvular disease, and 11 had a carotid artery stroke). Forty of the 47 (86 percent) had SDDs. By contrast, of the 153 AMD patients who did not have these severe diseases, 57 had SDD (43 percent). The researchers concluded that AMD patients with severe cardiovascular disease and stroke were nine times more likely to develop cardiovascular disease than those without.
“This work illustrates the fact that ophthalmologists may be the first physicians to detect systemic disease, particularly in asymptomatic patients,” says co-investigator Richard P. Rosen, chief of retina at Mount Sinai Health System. “Detection of SDDs in the retina should lead to referral to the individual’s primary care provider, especially if no previous cardiologist was involved. This may prevent a life-threatening cardiac event.”
“This study opened the door to more fruitful multidisciplinary collaborations between ophthalmology, cardiology, and neurology services,” says Jagat Narula, MD, PhD, director of the Cardiovascular Imaging Program at Zen and the Michael A. Weiner Cardiovascular Institute at the School of Medicine. Icahn Medicine at Mount Sinai. “We should also focus on determining disease severity by imaging angiography in cardiology and neurology clinics, and assessing its impact on AMD and SDDs through retinal imaging. This way we can know which vascular patients to refer for blinding detection and prevention.”
This study was funded by a Regeneron Pharmaceuticals Investigator study, Research to Prevention Blindness Challenge grants, the Macula Foundation, a Bayer-Global Ophthalmology Award, and the International Ophthalmological Council-Alcon Fellowship.