What is macular degeneration?

Age-related macular degeneration (AMD), is one of the leading causes of vision loss. In the United States, AMD affects approximately 1% of people aged 65-75, and another 10-20% of the population above the age of 85. Macular degeneration comes from cellular damage in the macula, the central part of the retina responsible for sharp, detailed central vision needed for activities such as reading, driving, and recognizing faces.

Once the macula becomes damaged, it causes gradually progressive vision loss or sudden loss in central vision, while peripheral vision mostly remains normal. Therefore, AMD can develop slowly in some people, and much faster in others. If you have early AMD, it is very rare that you notice a loss of eyesight. This is why it is very important to get regular eye exams to ensure that you can be proactive in slowing down the condition.

Types of AMD and How They Develop

There are two types of AMD that affect the macula: dry and wet.

Dry AMD

All patients with AMD start with the dry type, and approximately 90% of all people with AMD have the dry type. Dry AMD is caused by build up of waste products from the retina’s high photoreceptor metabolism in the macula. These waste products form deposits called drusen. Drusen are yellow deposits of lipids and protein waste products located under the retina. People with AMD cannot efficiently remove this waste. Over time, the drusen population and size begin to increase, thereby, increasing the severity of the condition. 

In early stages of Dry AMD, you won’t notice any changes to your eyesight, but your eye care professional will notice changes in your macula. In the moderate stage of Dry AMD, your vision will begin to get blurry centrally. If you reach the advanced stage, you may completely lose your central vision. In the advanced stage of dry AMD, there is a condition known as geographic atrophy, which causes large patches of cell loss. This results in patchy loss of central vision.

Wet AMD

Wet AMD is less common than dry AMD, and it happens when there is blood vessel growth in the macula beneath your retina. In wet AMD, levels of VEGF (vascular endothelial growth factor) increase significantly, which causes the production of abnormal and leaky blood vessels into the retina. These vessels are very weak, so fluid and blood leak out and accumulate under the retina, causing cellular damage and subsequent vision loss. Wet AMD is much more aggressive than dry AMD, and is more likely to lead to sudden vision loss. Wet AMD requires immediate treatment.

From Dry to Wet

AMD always begins as the dry form and may later turn wet in approximately 10-15% of patients.

Risk Factors - What Increases the Odds?

Age is the strongest risk factor, and risk rises sharply after the ages 55-60. However, AMD is caused by a combination of non-modifiable and modifiable factors.

Non-modifiable risk factors

• Getting older

• Family history of AMD or genetics

• Some demographic factors such as being female or being Caucasian increases the risk

Modifiable risk factors

• Exposure to UV light

• Smoking

• Poor diet and high body-mass index

• High blood pressure, high cholesterol, cardiovascular disease

• Prior cataract surgery may also contribute in some cases

Prevention and Healthy Habits

• Do not smoke

• Be aware of family history

• Eat leafy greens

• Avoid highly processed snacks/junk food

• Exercise daily

• Wear sunglasses and a hat in sunlight

• Maintain a healthy weight

• Normal blood sugar, blood pressure, and cholesterol levels

Symptoms and Early Signs of Dry AMD

Dry AMD commonly develops gradually and affects both eyes, although one eye may be worse than the other. Because of this slow and gradual progression of dry AMD, it is often difficult for individuals to notice visual changes right away, or at all. Common symptoms and signs of dry AMD may include:

• Blurred central vision, especially noticeable when doing close work or reading

• Difficulty adjusting from normal form bright to dim lighting conditions

• Colors appear washed out

• Patchy central vision loss

Symptoms and Early Signs of Wet AMD

Wet AMD often develops from the dry form, but the progression is more rapid and severe. Warning signs may include:

• Completely dark or empty areas of central vision

• Rapid loss of visual clarity, which makes fine details much harder to distinguish

• Objects appearing smaller or farther away than they are

• Severely faded colors

• Visual distortion, where straight lines appear to be curved or missing in sections

Because Wet AMD can cause sudden, irreversible damage, anyone experiencing abrupt distortion or loss of central vision needs to consider seeking immediate evaluation by an ophthalmologist.

Diagnosis

• Dilated eye exam: eye drops dilate and enlarge your pupils so the eye doctor can view drusen and damage in the macula.

• Amsler grid test: displays numerous straight (horizontal and vertical) lines with a large dot in the middle. If you see distortion in the lines, it may indicate that you have wet AMD.

• Fluorescein angiography: fluorescein is injected into a vein in your arm by a medical professional. The dye is tracked through a specialized camera as it passes through your eye’s blood vessels. The photos taken by this camera disclose any leaks in your macula.

• Optical coherence tomography: The patient looks into the lens as the machine takes cross-sectional images of the macula.

• Optical coherence tomography angiography: A non-invasive imaging technique that uses light waves as a diagnostic tool. The machine takes photographs and creates 3D images of the blood flow in the patient’s eye.

Treatment and Management

To put it simply, there is no cure for macular degeneration. Because of this, even with the proper treatments, you may still continue to experience symptoms. However, starting the treatment process early can slow the progression of the disease and even reverse the damage in cases of wet AMD.

Treatments for AMD include:

The Age-Related Eye Disease Studies (AREDS and AREDS2) have found many supplements that help reduce risk of progression and vision loss in dry AMD.

• Vitamin E

• Vitamin C

• Lutein

• Copper

• Zinc

• Zeaxanthin

Treatments for Wet AMD

There are currently two available treatments that slow down the progression of Wet AMD:

• Anti-VEGF injections

• Laser Therapy (infrequently)

Treatment for Severe Dry AMD (Geographic Atrophy)

• Complement inhibitor injections

Injections and lasers are only performed by trained ophthalmologists.

Living with AMD

As the macula weakens, vision steadily declines, and it may become increasingly difficult to do basic activities such as reading, driving and recognizing faces. Because AMD only affects central vision, your peripheral vision will remain intact. There are things you can do to work around the declining central vision. You can try repositioning things or objects in your home to make use of your areas of sharper vision. You may find some spaces appear to be much darker than they are. To compensate for this, use brighter light bulbs in a room, and when you’re doing a task, try shining a bright light directly on what you’re trying to do. Because having AMD makes color muted, purchase bright colored belongings to help you recognize objects. For example, organizing brightly colored pillows or blankets make it easier to see seating. Using colored paint, you can also put vibrant colors on different household objects, such as toothbrushes, books, electronics, kitchen supplies, etc. You can also use a magnifying glass as a reading aid.

I encourage you to contact your local eye care professional to arrange an exam for AMD. If you found this page helpful, please join our mission, and sign the Macular Mission Pledge in order to help us continue to achieve our goal of spreading awareness about AMD. Thank you and remember, EARLY DETECTION SAVES SIGHT!