Macular Degeneration Causes, Symptoms, and Treatment Options
Causes, Symptoms, and Treatment Options
By Roger M. Kaldawy, M.D.
Milford Franklin Eye Center
Macular degeneration, also known as age-related macular degeneration (AMD), is a progressive eye condition that affects millions of people worldwide. It is a leading cause of vision loss, particularly among older adults. Macular degeneration primarily affects the macula, a small area located near the center of the retina responsible for sharp, central vision. This article aims to provide an overview of macular degeneration, including its causes, symptoms, and available treatment options.
Causes of Macular Degeneration
While the exact causes of macular degeneration remain unknown, several risk factors have been identified. Age is a significant factor, as the condition predominantly affects individuals over the age of 50. Genetic factors, family history, smoking, obesity, high blood pressure, and prolonged exposure to ultraviolet light are also associated with an increased risk of developing macular degeneration.
Types of Macular Degeneration
There are two main types of macular degeneration: dry (atrophic) AMD and wet (neovascular) AMD.
Dry AMD is the most common form, accounting for approximately 85-90% of cases. It is characterized by the gradual breakdown of the macula due to the accumulation of drusen, yellow deposits beneath the retina. As the condition progresses, central vision becomes blurred, making it difficult to perform tasks such as reading or recognizing faces.
Wet AMD is less common but more aggressive than dry AMD. It occurs when abnormal blood vessels develop beneath the macula and leak blood or fluid, leading to rapid and severe vision loss. Individuals with wet AMD may experience distorted or wavy central vision, a dark spot in the center of their visual field, or rapid visual decline.
Symptoms and Diagnosis
The early stages of macular degeneration often present no noticeable symptoms, making regular eye exams crucial for early detection. As the condition progresses, symptoms may include:
Blurred or distorted central vision
Difficulty reading or performing activities that require fine detail
Dark or empty areas in the central visual field
Decreased brightness or intensity of colors
Difficulty recognizing faces
A comprehensive eye examination, including a dilated pupil examination, visual acuity test, and imaging tests such as optical coherence tomography (OCT) or fluorescein angiography, can help diagnose macular degeneration and determine its type and severity.
Macular degeneration is a progressive eye condition that affects the central portion of the retina, called the macula. Although there is no known cure for macular degeneration, there are several treatment options available that can help slow down its progression and manage the symptoms. Here are some of the common treatment options:
Anti-vascular endothelial growth factor (anti-VEGF) drugs are injected into the eye to reduce the growth of abnormal blood vessels in the retina. These drugs include medications like ranibizumab (Lucentis), bevacizumab (Avastin), and aflibercept (Eylea). Anti-VEGF therapy has shown significant success in stabilizing or improving vision in many cases of macular degeneration.
Photodynamic Therapy (PDT)
This treatment involves the use of a light-activated medication called verteporfin (Visudyne). The medication is injected into a vein, and then a laser is applied to the abnormal blood vessels in the retina to activate the drug, causing the vessels to close and reduce their leakage.
In some cases, laser therapy may be used to target and destroy abnormal blood vessels in the macula. This treatment is known as focal laser photocoagulation.
Implantable Miniature Telescope
For individuals with end-stage macular degeneration in both eyes and severe vision loss, an implantable miniature telescope (IMT) may be an option. The IMT is surgically placed in one eye to improve central vision by magnifying the images that reach the healthy portion of the retina.
Low Vision Aids
These include devices such as magnifying glasses, telescopic lenses, and electronic visual aids that can help individuals with macular degeneration make the most of their remaining vision.
Certain lifestyle modifications can help manage macular degeneration. These include quitting smoking, eating a healthy diet rich in antioxidants and nutrients (e.g., leafy green vegetables, fish, and fruits), exercising regularly, maintaining normal blood pressure and cholesterol levels, and protecting the eyes from harmful ultraviolet (UV) light.
The AREDS study conducted by the National Eye Institute and concluded in 2001. It showed that the AREDS formula can reduce patients’ risk of the advanced form of AMD by about 25 percent. The formula helps protect people’s central vision, which is needed for reading, driving, recognizing faces and other daily activities.
The AREDS 2 study, which concluded in 2011, tested several antioxidant nutrients that earlier research had suggested might protect the eyes: lutein, zeaxanthin, and omega-3 fatty acids. Omega-3 fatty acids are produced by plants and are present in oily fish such as salmon. Lutein and zeaxanthin are carotenoids, a class of plant-derived vitamins that also includes beta-carotene, and are present in leafy green vegetables. The body uses these nutrients to maintain the health of the retina, the part of the eye that can be damaged by AMD. The AREDS 2 research team did find that the risk of developing advanced AMD was reduced by about 18 percent in study participants who took the variant that included lutein and zeaxanthin but no beta-carotene, compared with participants who took the variant that had beta-carotene but no lutein or zeaxanthin. And those participants whose diets were low in lutein and zeaxanthin at the start of the study, but who took a variant with lutein and zeaxanthin during the study, were about 25 percent less likely to develop advanced AMD, compared with similar participants who did not take lutein and zeaxanthin.
The researchers say that removing beta-carotene from the AREDS formula and adding lutein and zeaxanthin will result in a single formula that is safe and effective for all AMD patients. Another recent AREDS report showed that the benefits of taking the AREDS formula appear to be long-lasting. Participants in the first AREDS study who took the original formula daily for five years continue to enjoy a 25 percent lower risk of developing advanced AMD.
It’s important to note that the choice of treatment depends on the type and severity of macular degeneration, as well as individual factors. If you or someone you know has macular degeneration, it’s crucial to consult with an ophthalmologist or retina specialist who can provide personalized recommendations and guidance based on the specific situation.
At Milford Franklin Eye Center, we use state-of-the-art technology to treat a variety of eye problems, including macular degeneration. We are proud to have a Boston Harvard dedicated retina specialist in our practice, specializing in the treatment of retinal eye disease and AMD. With the presence of this service and equipment that rivals the best found in major teaching eye hospitals, our practice continues to provide world class eye care closer to home.
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