What is macular degeneration?
What is macular degeneration?
Macular degeneration — also called age-related macular degeneration (AMD or ARMD) — is a vision change that can gradually create blurry vision over time.
AMD affects the macula, the small central area of the retina that maintains our sharpest vision. The health of the macula determines our ability to read, recognize faces, drive, watch television, use a digital device, and perform any other detailed visual task.
A patient with AMD gradually loses central vision but maintains peripheral or side vision. Blindness is rare in AMD.
Macular degeneration is the leading cause of vision loss among older Americans. According to statistics, one-third of males and one-quarter of females over 75 have some form of AMD.
The prevalence of AMD and the severity of vision loss increases with age, according to the American Optometric Association.
AMD may occur in one or both eyes and may affect each eye differently. AMD is most common in the white population.
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Types of macular degeneration
There are two types of macular degeneration: Dry AMD and Wet AMD
Dry AMD (also called non-exudative AMD) is the most common form, affecting 80-90% of AMD patients.
Dry AMD is due to an accumulation of proteins in the macula that causes the retinal cells above them to lose function. These protein deposits are called drusen. Most patients with dry AMD notice a gradual, painless loss of vision that progresses with time.
Wet AMD (also called exudative AMD) is a more visually threatening condition and accounts for 10-20% of AMD cases.
Wet AMD is caused by leaky blood vessels in the retina. These abnormal blood vessels may leak fluids or blood into the back of the eye.
Patients with wet AMD typically experience more significant vision loss than those with dry AMD. The vision loss caused by wet AMD is often noticed by the patient once the condition is very serious.
In some cases, wet AMD can cause sudden vision loss.
Symptoms of macular degeneration
Early signs of vision loss from AMD include shadowy areas in your central vision or unusually fuzzy or distorted vision. Some patients may notice wavy or distorted words when reading.
Additional symptoms include difficulty seeing details in poor lighting conditions and glare sensitivity.
Many patients do not notice the symptoms of AMD if they are present in only one eye or more pronounced in one eye than the other. When viewing with both eyes simultaneously the symptoms of blur and distortion may not be noticed.
Causes of macular degeneration
Though macular degeneration is associated with aging, research suggests there also may be a genetic component to the disease. Researchers have noted a strong association between development of AMD and presence of a variant gene.
Some researchers believe that over-exposure to sunlight also may be a contributing factor in development of macular degeneration, but this theory has not been proven conclusively.
Risk factors for developing macular degeneration include:
Gender (AMC affects more women than men)
Obesity and inactivity
The American Academy of Ophthalmology (AAO) notes that findings regarding AMD and risk factors have been contradictory, depending on the study. The only risk factors consistently found in studies to be associated with AMD are aging and smoking.
Treatments for macular degeneration
There is no cure for macular degeneration, but some treatments may delay its progression or even improve vision.
Treatments for macular degeneration depend on whether the disease is in its early-stage dry form or in the more advanced wet form.
For dry AMD, there are no FDA-approved treatments, but nutritional supplements containing antioxidant vitamins can reduce the risk of dry AMD progressing to sight-threatening wet AMD.
For wet AMD, the goal of most treatments is to shrink or stop abnormal blood vessel growth and prevent the leakage of fluid into the retina. The first line of treatment is the injection of a medication (Avastin, Lucentis or Eylea) directly into the affected eye. Additional medical and laser procedures are also available to treat wet AMD.
For AMD patients who have suffered any degree of vision loss, low vision devices such as magnifiers, telescopes and apps on digital devices can help to maximize vision potential.
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When to see an eye doctor
If you notice sudden or gradual changes in your central vision, see your eye doctor to rule out macular degeneration as the cause. Yearly, comprehensive eye examinations are recommended as preventative care, especially for those 65 and older.
Eye doctors can detect early signs of macular degeneration before patients experience symptoms. Your eye doctor will likely dilate your eyes to evaluate the retina/macula. Your eye doctor also may use imaging tools to observe any retinal changes.
If you are an AMD patient who has suffered vision loss, schedule an examination with an eye care practitioner specializing in low vision rehabilitation These vision care specialists will evaluate your vision and your daily needs to maximize function.
Currently, the best ways to protect your eyes from developing macular degeneration are to eat a healthy diet, exercise and wear sunglasses that protect your eyes from the sun's harmful ultraviolet (UV) rays.
As you grow older, see an eye doctor regularly as comprehensive eye exams play an important role in AMD prevention.
WHEN WAS YOUR LAST EYE EXAM? Find an eye doctor near you and schedule a comprehensive eye exam.
Page published in March 2019
Page updated in July 2021