Understanding the Different Types of Macular Degeneration

Macular degeneration is an eye disease caused by damage to the macula in the retina, a sensitive piece of tissue in the back of the eye. Also called AMD or age-related macular degeneration, it is more common with age, particularly over age 65.

There are different types of macular degeneration, including dry macular degeneration and wet macular degeneration. Another macular disease called Stargardt disease is a dystrophy with similar symptoms, but it is inherited and occurs to people much younger in life.

This article will discuss these three macular diseases, typical symptoms, what is happening in the eye, and risk factors.

Dry Macular Degeneration

An estimated 11 million people in the United States have some form of macular degeneration. Dry macular degeneration is the most common type of macular degeneration, affecting 85% to 90% of those with the disease.

With dry macular degeneration, the retina’s macula becomes thinner over time. Drusen, which are a buildup of retinal cellular waste products made up of lipid and protein, form within the macula area.

The macula is responsible for your central vision. Central vision is what you see in the middle of your vision when you look straight ahead. It is different from your side or peripheral vision. These drusen disrupt this macular area affecting your central vision.

In the early stage, you may not have any symptoms. As dry macular degeneration progresses, symptoms include:

• Blurry central vision
• Blind spots in your vision (also called geographic atrophy): For instance, you may be reading something, but find that several letters are missing.
• Decreased contrast sensitivity: This means that letters may be hard to read if they are of a similar color to a screen background or the piece of paper they are on.
• Having trouble seeing in a darkened room: It may take your eyes longer than it normally would to adjust.

Depending on its progression, dry macular degeneration may also be called early-stage or intermediate-stage AMD. If it causes vision loss, it is late-stage AMD.

Dry macular degeneration is less advanced than wet macular degeneration. However, it can still cause vision problems. So, it is still important to get it evaluated with regular eye exams, as it can progress to the wet form.

Also, despite its name, dry macular degeneration is not the same thing as dry eye. Dry macular degeneration just means there is no bleeding, as there is in wet macular degeneration.

Wet Macular Degeneration

Among those with macular degeneration, 10% to 15% will have the wet form of the disease. Wet macular degeneration is more serious than dry macular degeneration. It causes you to lose vision faster than with dry macular degeneration. Wet macular degeneration is considered late-stage AMD.

When you have wet macular degeneration, blood vessels grow abnormally under the retina. The blood vessels can leak blood and other fluids and lead to macula scarring.

The main symptom of wet macular degeneration is a gray, red, or black blind spot in your central vision. This loss of vision can happen quickly. This is why regular eye exams are important to help watch for signs of macular degeneration before they become worse.

If you have wet macular degeneration, you may have to monitor it with something called an Amsler grid. An Amsler grid is a type of grid that you look at while holding it at a reading distance. While using the grid, you keep one eye closed or covered while you test the other eye. Your eye doctor will want to know if any lines are missing or look wavy.

Stargardt Disease

Stargardt disease is different from wet and dry macular degeneration because it is an inherited form of macular disease. It is also called juvenile macular degeneration or Stargardt muscular dystrophy.

About 30,000 people in the United States have Stargardt disease, as it occurs in one person out of every 8,000 to 10,000. Other genetic disorders can cause macular degeneration, but Stargardt disease is the most common form.

With Stargardt disease, progressive damage to the macula occurs just as it does with age-related forms of macular degeneration. However, central vision loss happens in your childhood or teen years. Some people may not notice any changes to their vision until they are an adult. Stargardt disease does not usually cause complete blindness.

Symptoms of Stargardt disease include:

• Gradual central vision loss in both eyes
• Gray, hazy, or black spots in your central vision
• More sensitivity to light

While age-related macular degeneration does not usually cause loss of peripheral vision, Stargardt disease can lead to the loss of some side vision with age.

Risk Factors

Risk factors for the age-related forms of macular degeneration include:

• Age over 50 years
• A family history of the disease
• Being overweight
• Being White
• Cigarette smoking
• Eating foods high in saturated fats
• Having heart disease
• Having high blood pressure

For Stargardt disease, the risk factor is an inheritance of certain gene mutations or changes, such as a mutation of the ABCA4 gene.

Summary

The most common types of macular degeneration are age-related dry macular degeneration and age-related wet macular degeneration. An inherited form, Stargardt disease, is less common and can affect people at an earlier age.

The symptoms are related to a loss of central vision, as the macula is affected by drusen (in the dry form) or blood vessel formation and leakage (in the wet form). It can lead to loss of vision.

A Word From Verywell

It’s important to schedule regular eye exams so an eye doctor can monitor for certain common eye diseases, such as macular degeneration. If you have macular degeneration, your eye doctor can help monitor the disease progression and offer any available treatments. Make sure to return for those regular eye exams or treatment appointments.