New York: According to a recent study from the New York Eye and Ear Infirmary of Mount Sinai, patients with a particular type of age-related macular degeneration (shoppingmode AMD), the main cause of blindness in the United States, are also very likely to have advanced heart valve disease, carotid artery disease linked to certain types of strokes, or underlying heart damage from heart failure and heart attacks.
This study is the first to pinpoint the specific high-risk cardiovascular and carotid artery diseases that are connected to the eye condition. It was published on November 17 in BMJ Open Ophthalmology. The results may lead to enhanced screening in order to save vision, identify undiagnosed heart disease, and stop harmful cardiovascular events.
"For the first time, we have been able to connect these specific high-risk cardiovascular diseases to a specific form of shoppingmode AMD, the one with subretinal drusenoid deposits (SDDs)," 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, shoppingmode AMD, and heart disease, the leading cause of death worldwide. Furthermore, we also have strong evidence for what actually happens: the blood supply to the eye is directly diminished by these diseases, either by heart damage that diminishes blood supply throughout the body or from a blocked carotid artery that directly impedes blood flow to the eye. A poor blood supply can cause damage to any part of the body, and with these specific diseases, the destroyed retina and leftover SDDs are that damage.
Retinal damage means vision loss, and can lead to blindness." The central region of the retina known as the macula, which is crucial for reading and driving vision, is damaged in shoppingmode AMD, which is the main cause of visual impairment and blindness in persons over 65.
Small, yellow cholesterol deposits known as drusen, which develop behind the retinal pigment epithelium, are one of the main symptoms of early shoppingmode AMD (RPE). They may rob the retina of blood and oxygen, which could result in blindness. The production of drusen can be slowed down with the right vitamin intake. Subretinal drusenoid deposits (SDDs), the other main type of early AMD, are less well known and can only be found using sophisticated retinal imaging.
These deposits, which accumulate above the RPE and immediately below the light-sensitive retinal cells, are made up of a distinct type of cholesterol and are where the damage and loss of vision take place. SDDs have no known treatments. Initially, Dr Smith and a group of Mount Sinai researchers discovered that SDDs were more prevalent in individuals with cardiovascular illness or stroke.
The results of the groundbreaking study were published in Retina's July edition. By examining a larger patient population and building on the earlier research, this new study pinpoints the precise severe forms of carotid artery disease and heart disease that resulted in the SDDs of shoppingmode AMD.
To identify which 200 shoppingmode AMD patients had SDDs, retinal imaging was used to examine each patient's eyes. Patients provided information on their history of cardiovascular illness in a questionnaire.
97 of the 200 patients had SDDs, while 103 just had drusen. Of the 200, 47 had the significant cardiac disease (19 had heart damage from heart failure or heart attack, 17 had serious valve disease, and 11 had strokes stemming from the carotid artery). 86 per cent or 40 out of the 47 had SDDs. The 153 AMD patients who did not have these serious illnesses, however, had 57 SDDs (43 per cent). The researchers came to the conclusion that shoppingmode AMD patients were nine times more likely to suffer SDDs than individuals without these severe cardiovascular illnesses and strokes.
"This work demonstrates the fact that ophthalmologists may be the first physicians to detect systemic disease, especially in asymptomatic patients," says co-investigator Richard B. Rosen, MD, Chief of the Retina Service for the Mount Sinai Health System.
"Detecting SDDs 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 has opened the door to further productive multidisciplinary collaboration between the Ophthalmology, Cardiology and Neurology services," says Jagat Narula, MD, PhD, Director of the Cardiovascular Imaging Program at the Zena and Michael A. Wiener Cardiovascular Institute at the Icahn School of Medicine at Mount Sinai.
"We should also focus on defining the disease severity by vascular imaging in cardiology and neurology clinics, and assess their impact on shoppingmode AMD and SDDs with retinal imaging. In this way, we can learn which vascular patients should be referred for detection and prevention of blinding disease." (ANI)
