Wet age-related macular degeneration (AMD)

Normal vision and vision with macular degeneration depicted

As macular degeneration develops, clear, normal vision (shown left) becomes impaired by a distorted blur with missing areas. With advanced macular degeneration, a blind spot typically forms at the center of your visual field (shown right).

 

What is wet age-related macular degeneration?

Wet macular degeneration doesn’t affect peripheral vision but can cause significant central vision loss.

Age-related macular (MAK-u-luhr) degeneration is a chronic eye disease that affects the part of the retina responsible for your central vision (the macula). The disease is one of the most common causes of vision loss in older adults over 65. Macular degeneration typically causes blurred or distorted vision or a blind spot in the center of your visual field. It doesn’t affect your side (peripheral) vision

Wet macular degeneration is one of two types of age-related macular degeneration. The other type — dry macular degeneration — is more common and may be less severe. The wet type, which affects only about 10 to 15 percent of those with macular degeneration, always begins as the dry type.

 

Wet macular degeneration vision loss can be caused by:

        • Abnormal blood vessel growth. Abnormal blood vessels can grow into the macula starting from a layer beneath the retina, called the choroid. These blood vessels can leak fluid or blood, interfering with the retina’s function.
        • Fluid buildup in the back of the eye. When fluid leaks under the retina, it can collect and distort the macular layers.

SYMPTOMS

AMD symptoms

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 NEITrusted Source, dry AMD is categorized into three stages:

          • 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, all people with AMD must 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

CAUSES

Dry AMD

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

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.

Risk Factors

AMD is very common, affecting around 11 million Americans, according to the National Eye Institute (NEI)Trusted Source.

Researchers don’t know exactly why it develops, but there are a few associated risk factors, according to the AAO and NEI.

These include:

        • 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.

 

DIAGNOSIS

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 layersTrusted Source of 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.

Learn more about what to expect at a routine eye exam.

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.

AMD treatment and management

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

Wet AMD treatments can help stop further vision loss and reduce the number of irregular blood vessels in your eyes.

Currently, there are two treatment optionsTrusted Source for wet AMD:

        • 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.

Dry 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 Age-Related Eye Disease Study (AREDS)Trusted Source, which was then followed by a second study, AREDS2. They found a combination of certain vitamin and mineral supplements can help lower the risk of progression toward advanced AMD by around 25 percent.

The supplement recommendations by the 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
lutein 10 mg
zeaxanthin 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.

Learn more about the best foods for eye health.

Coping strategies

Low vision tools can also help you adapt to vision changes and maximize the vision you have.

According to the NEITrusted Source, strategies for dealing with AMD vision loss include:

        • 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

What is the difference between dry and wet macular degeneration?

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.

 

When to See a Doctor

See an eye doctor regularly and as soon as possible if you notice any changes to your vision. Wet age-related macular degeneration can appear suddenly and progress quickly. Treatment may help slow vision loss and preserve independence.

Can you prevent AMD?

There’s no way to prevent AMD. However, you can take steps to reduce your risk and keep your eyes healthy. These include:

Takeaway

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.

 

Reference(s): Mayo Clinic Home Pagehealthline.com

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