February 8, 2018 | Categories: Health Care
Age-related macular degeneration is the leading cause of loss of visual acuity (vision sharpness) among people over 50 years old. “Macular degeneration is also the most common cause of legal blindness in this country,” says Ron Adelman, MD, director of Retina and Macula Center at Yale Medicine. The condition, which affects the center of the retina, called the macula, affects more than 10 million Americans – more than cataracts and glaucoma combined. Yale Medicine has a cutting-edge approach to retinal conditions. For some of the retinal surgeries at our installations, the success rate is above 90 percent.
Although a patient may not have symptoms for a while, the first indicator of macular degeneration can be that the patient doesn’t see colors as brightly or intensely, or straight lines could seem warped. As the condition progresses, symptoms can include a gradual or even sudden loss of central vision. The patient might also perceive dark, blurry areas in the center of her vision.
The biggest risk factor for macular degeneration is age. The condition also has higher incidence rates among people with a family history of it, Caucasians, and smokers. AMD is also more common among women, and additional risk factors include high blood pressure, high cholesterol, heart disease, light iris color, sun exposure, farsightedness and even a low dietary fish intake.
When the cells of the macula deteriorate, images aren’t received correctly. Still, early stage AMD doesn’t affect vision. Later, if the disease progresses, people experience wavy or blurred vision, and, if the condition continues to worsen, central vision may be completely lost.
After discussing a patient’s vision issues, an ophthalmologist will do a clinical examination with a slit lamp, a low-power microscope combined with a high-intensity light source that can be focused as a thin beam and looks at the front of the eye.The doctor may also use several types of imaging (such as fluorescein angiography, indocyanine green angiography, or optical coherence tomography) to determine if AMD is in the retina and in the layers beneath it.
According to those findings, AMD is classified as “dry” or “wet.”
“If ‘wet macular degeneration’ (which is also known as neovascular AMD) is untreated, the central vision would be significantly affected, causing a legal blindness,” Dr. Adelman says.
With “dry AMD,” (non-neovascular AMD) there is a gradual breakdown of the light-sensitive cells in the macula that convey visual information to the brain, and degeneration of the supporting tissue beneath the macula. Those changes can cause vision loss, which is why, Dr. Adelman says, the conditions “need to be treated in a timely manner.” “Wet AMD,” (neovascular AMD) is a late-stage macular degeneration that occurs when abnormal blood vessels grow underneath the retina. These new blood vessels can leak fluid and blood, which may lead to swelling and damage of the macula. The damage may be rapid and severe, and if it’s untreated, the central vision would be significantly affected, and causes a legal blindness, says Dr. Adelman. So, many retinal diseases need to be treated in a timely manner.
The ophthalmologist may suggest a common retinal procedure, “intravitreal injection,” which means injection into the eye. This particular injection is likely to combat vascular endothelial growth factor (VEGF), a protein that promotes the growth of new abnormal blood vessels in the eyes. “Although that seems to be painful, patients tolerate it very well,” Dr. Adelman says. “With some topical anesthetics, like eye drops, patients feel relatively comfortable a minute or two after the procedure.” Patients may need several of those injections over the course of a month or longer to treat the affected eye or eyes.
Intravitreal injection is commonly used as a very effective treatment for wet macular degeneration, although the condition can’t be cured. “With those injections of medications, 95 percent of the time, patients can have stable vision again and do not lose vision,” Dr. Adelman says.
The National Eye Institute conducted testing and found that daily intake of some high-dose vitamins and minerals can slow progression of the disease in people who have intermediate AMD, and those who have late AMD in one eye.
One trial found that vitamins C and E, and beta-carotene, zinc and copper, could reduce the risk of late AMD by 25 percent. Another trial found that adding lutein and zeaxanthin or omega-3 fatty acids may help reduce the risk of late AMD.
Retinal surgeries are commonly performed at Yale Medicine, and the success rate has significantly improved in recent years. Patients may come in the morning, have the surgery, and then leave the hospital or the surgery center by noon, Dr. Adelman says.
“At Yale Medicine, our center of attention is on the patient and the best outcome for patients and their families,” Dr. Adelman says.
The team is also at the forefront of developing new therapeutics for the condition, he says. “We have participated in a large number of clinical trials that resulted in some of the new treatment for retinal diseases,” Dr. Adelman says. “In addition, our researchers have helped to develop new approaches in the lab for retinal conditions that are slowly going to be introduced to clinical medicine.”
This article was originally written for the Yale School of Medicine’s website in 2016.
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