Both types of age-related macular degeneration (AMD) can lead to blurriness and visual changes. Dry AMD progresses slowly and causes permanent damage while wet AMD is more severe but more treatable.
Age-related macular degeneration (AMD) is a very common visual impairment. Among adults over 65, AMD is the
AMD doesn’t cause total blindness, but it can severely impair central vision in some people. Our central vision is what allows us to see shapes, colors, and details. Without central vision, it’s hard to recognize faces, read, or drive.
AMD is classified as either wet or dry. Dry AMD is much more common and usually progresses slowly. Wet AMD can lead to more rapid and severe vision loss but is more treatable than dry AMD.
We’ll go over the causes, types, and treatments available for both types of age-related macular degeneration.
The cause of age-related macular degeneration depends on the type of AMD that is occurring.
Dry AMD causes
Dry AMD happens gradually. It’s caused by changes that occur underneath the retina in an important region called the macula. Your macula is in the center of your retina and helps you see clearly.
During dry AMD, clusters made up of lipids (fats) and proteins build up under your macula. These are called drusen. According to the American Academy of Ophthalmology (AAO), large drusen that interfere with central vision are a defining feature of AMD.
This thinning or wearing down of the macula can happen to some people as they age.
Wet AMD causes
Wet AMD happens when irregular blood vessels begin to grow under your eye’s macula. These blood vessels leak fluid into the retina and reduce vision. Over time, scarring within the retina may occur.
Usually, vision loss comes on faster in wet AMD compared to dry AMD.
AMD is very common, affecting around 11 million Americans, according to the
Researchers don’t know exactly why it develops, but there are a few associated risk factors, according to the AAO and NEI.
- Having drusen under your retina. Having drusen isn’t a sign of vision loss. However, the presence of drusen is linked to an increased risk for AMD. Large drusen can impair central vision and become a defining feature of AMD.
- Being over 50. You’re at an increased risk for AMD as you get older due to natural wear and tear on your eyes. People over 50 are at the highest risk of AMD.
- Having a family history of AMD. You have a higher risk of AMD if a parent of a sibling has AMD. There’s some evidence that AMD might be caused by inherited genetic mutations, but researchers are still investigating this link.
- Race. Researchers have repeatedly found that older white people are at the highest risk of developing AMD, but the exact reasons are unclear.
- Being a smoker. Smoking increases your risk for multiple health conditions, including AMD.
- Having high blood pressure. High blood pressure (hypertension) is linked to an increased risk of AMD.
- Having obesity. You’re at a higher risk for AMD if you’re overweight or obese.
- Eating a diet high in saturated fats. Foods high in saturated fat include certain dairy products, oils, and processed meats.
AMD doesn’t cause total vision loss, but it does cause visual impairment. The exact symptoms and progression depend on the type of AMD you have as well as other individual health factors.
Dry AMD symptoms
According to the
- Early. This usually causes no symptoms but might be identified during a routine dilated eye exam.
- Intermediate. Some people still have no symptoms, but others may experience central vision blurriness and trouble seeing in low light.
- Late. In both dry and wet AMD, late stage symptoms may include seeing straight lines as wavy or crooked. Your vision may become significantly less sharp and have some blank spots.
Once dry AMD progresses to late stage dry AMD, the symptoms are the same as the symptoms of wet AMD.
In rare cases, dry AMD can become wet AMD. Since there is no way to predict if this will happen, it’s important that all people with AMD see their doctor for regular examinations.
Wet AMD symptoms
Wet AMD can cause you to see straight lines and edges as warped, wavy, or crooked.
You might also notice:
- a blurry area in the middle of your vision
- blank spots in your vision
- difficulty seeing in dim lighting
- that colors are less vivid than they once were
An ophthalmologist can check for AMD during a dilated eye exam. The first step in a dilated eye exam is to receive eye drops. The eye drops allow your pupils to widen, or dilate, so the ophthalmologist can see into your eye better and check its health.
After having your eyes dilated, they may feel a little uncomfortable and be very sensitive to light.
Your eye doctor might recommend additional testing to help confirm an AMD diagnosis. This could include:
- Optical coherence tomography (OCT). OCT uses a special light beam to
scan multiple layersof your eye’s tissues. It generates high quality, cross-sectional images. OCT is completely noninvasive and has become a go-to tool for diagnosing various eye diseases.
- Fluorescein angiography. This test uses a special dye alongside a type of retinal photography to help your doctor see both regular and irregular blood vessels in your eye. After receiving eye drops to widen your pupils, you will have an injection of yellow dye into your arm. The dye will quickly travel to the blood vessels in your eyes, causing them to shine or stand out. Your doctor will then take photos. There is no radiation exposure.
- Amsler grid test. Your eye doctor might have you look at an image called an Amsler grid to test for blurry or blank spots in your field of vision. The Amsler grid is a black grid with a black dot in the middle. If you have late AMD, it may cause these lines to appear wavy, warped, and blurred. The Amsler grid can also be used as a daily test for people with AMD.
It’s also possible to have AMD alongside other eye conditions, such as cataracts or glaucoma. This can cause complete vision loss in certain cases. It’s important to attend regular eye checkups to catch any vision changes.
There are a few different treatments available for AMD. Some treatments, such as treatments to help you adapt to low vision, can be helpful for people with either wet or dry AMD. Other treatments are specific to the type of AMD you have.
Wet AMD treatments can help stop further vision loss and reduce the number of irregular blood vessels in your eyes.
Currently, there are
- Anti-VEGF medications. Anti-VEGF treatment can stop the protein that causes blood vessels to grow and leak in the eye. This reduces how many irregular blood vessels are in your eye. Anti-VEGF medications are injected into the vitreous cavity at the back of your eye after a numbing agent is applied. The process usually takes around 10 to 15 minutes and may need to be repeated every few weeks to months.
- Photodynamic therapy (PDT). PDT uses lasers alongside a special light-sensitive medication called verteporfin. The lasers then target and break down blood vessels causing vision loss. This treatment is generally used alongside anti-VEGF drugs and only for severe cases of wet AMD.
There is no cure for dry AMD and no treatments known to reverse its effects on your vision.
However, the NEI conducted a large study called the
The supplement recommendations by study are as follows:
|Nutrient||AREDS formula||AREDS2 formula|
|vitamin C||500 mg||500 mg|
|vitamin E||400 IU||400 IU|
|beta carotene||15 mg|
|copper (cupric oxide)||2 mg||2 mg|
|zinc||80 mg||80 mg|
Both formulas are commercially available. Remember to talk with your doctor before adding any supplements to your diet. The first AREDS formula is not recommended for current and former smokers since beta carotene may increase lung cancer risk.
Additionally, eating nutrient-rich foods, like dark, leafy greens, vegetables, and fish, has been shown to help some people with dry AMD. Your eye doctor can help you figure out the right combination of dietary measures and vitamins to help with your dry AMD.
Low vision tools can also help you adapt to vision changes and maximize the vision you have.
According to the
- using sunglasses for UV protection
- using magnifiers when reading
- using brighter overhead lights or lamps to improve visibility
- trying screen readers or other assistive technologies
- making sure your home is easy to navigate
- consulting with a vision rehabilitation specialist
- seeing a therapist for emotional support
“I started watching TV programs on my computer, which was easier than the larger-but-more-distant TV screen in my living room.”
— Muriel J. Smith
There’s no way to prevent AMD. However, you can take steps to reduce your risk and keep your eyes healthy. These include:
AMD is a very common cause of vision loss in older adults.
Dry AMD makes up the majority of cases, progressing slowly and causing permanent vision damage. Wet AMD is rarer and more severe but also more treatable than dry AMD. Research suggests a combination of nutrient supplements can help slow down dry AMD.
The progression of wet AMD can be slowed and even partially reversed with anti-VEGF medications and laser treatment options.
Both types of AMD can lead to blurriness, blank spots, and wavy lines in the center of your vision. Low vision aids may be a useful management tool for both.
Talk with your doctor about your risk factors for AMD or any troubling symptoms you may be experiencing. Scheduling and attending routine eye exams, especially as you get older, is a great way to stay on top of your AMD risk and overall eye health.