Patients with a specific form of age-related macular degeneration (AMD), a leading cause of blindness in the United States, also have a high chance of having underlying heart damage from heart failure and heart attacks, or valvular disease advanced heart or carotid artery disease associated with certain types of stroke, according to a new study from the New York Eye and Ear Infirmary of Mount Sinai.
This research, published November 17 in BMJ Open Ophthalmology, is the first to identify which types of high-risk carotid artery and cardiovascular disease are linked to the eye disorder. The findings may prompt increased screening to save vision, diagnose undetected heart disease and prevent adverse cardiovascular events.
“For the first time, we were able to link these specific high-risk cardiovascular diseases to a specific form of AMD, that with subretinal drusenoid deposits (SDD),” explains lead author R. Theodore Smith, MD, PhD , Professor of 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. In addition, we also have strong evidence of what really happens: the influx of blood to the eye is directly reduced by these diseases, either from heart damage which decreases blood supply throughout the body or from a blocked carotid artery which directly prevents blood flow to the eye. blood can cause damage to any part of the body, and with these specific diseases, the destroyed retina and the remaining SDDs are that damage.Damage to the retina means loss of vision and can lead to blindness.
AMD is the leading cause of vision impairment and blindness in people over the age of 65 and is the result of damage to the central area of the retina called the macula, which is responsible for reading and driving vision. One of the main forms of early AMD is small deposits of yellow cholesterol called drusen, which form under a part of the retina called the retinal pigment epithelium (RPE). They can deprive the retina 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 drusenoid deposits (SDD), are less well known and require high-tech retinal imaging to detect. These deposits contain a different form of cholesterol and form above the RPE and just below the light-sensitive cells of the retina, where damage occurs and vision is lost. There is no known treatment for SDDs. Dr. Smith and a team of Mount Sinai researchers initially found that patients with cardiovascular disease or stroke were more likely to have SDD. That first-of-its-kind research was published in the July issue of Retina. This new study expands on previous work by examining a larger patient population and identifies the specific severe forms of heart disease and carotid artery disease that cause the SDDs of AMD.
The researchers scanned the eyes of 200 AMD patients with retinal imaging to determine which patients had SDD. Patients answered a questionnaire about their history of cardiovascular disease. Of the 200 patients, 97 had SDD and 103 had drusen only. Forty-seven of the 200 had severe heart disease (19 had heart damage from heart failure or heart attack, 17 had severe valve disease, and 11 had strokes resulting from the carotid artery). Forty of 47 (86%) had SDD. In contrast, of the 153 AMD patients who did not have these serious diseases, 57 had SDD (43%). The researchers concluded that AMD patients with these serious cardiovascular diseases and strokes were nine times more likely to have SDD than those without them.
“This work demonstrates the fact that ophthalmologists may be the first clinicians to detect systemic disease, especially in asymptomatic patients,” says co-investigator Richard B. Rosen, MD, head of Retina Service for the Mount Sinai Health System. “The detection of SDD in the retina should trigger a referral to the individual’s primary care provider, especially if no previous cardiologist has been involved. It could prevent a life-threatening cardiac event.”
“This study opened the door for further productive multidisciplinary collaboration between ophthalmology, cardiology, and neurology services,” says Jagat Narula, MD, PhD, director of the cardiovascular imaging program at Zena Cardiovascular Institute and Michael A. Wiener at the Icahn School of Medicine at Mount Sinai. “We should also focus on defining disease severity using vascular imaging in cardiology and neurology clinics and evaluating their impact on AMD and SDD with retinal imaging. This way we can know which vascular patients should be referred for detection and prevention of blinding disease.”
This study was funded by the Regeneron Pharmaceuticals Investigator-Initiated Study, Research to Prevent Blindness Challenge Grant, Macula Foundation, Bayer-Global Ophthalmology Award, and International Council of Ophthalmology-Alcon Fellowship.