What Is Macular Degeneration? Causes, Symptoms & Treatment

senior-male-with-macular-degeneration

Macular degeneration is a disease of the central retina (called the macula) that affects central vision. It is the leading cause of vision loss among people over age 65. 

Because it affects only central vision, macular degeneration does not cause total blindness. However, it can make most daily activities like driving and reading difficult or impossible.

What Causes Macular Degeneration?

The exact cause of macular degeneration is still not understood, but it is thought to be associated with atherosclerotic changes in the tiny blood vessels that nourish the macula, compromising the blood flow to this part of the retina.

What we do know is that age clearly plays a role in the progression of this disease. For this reason, it is often referred to as age-related macular degeneration (AMD).

Types of Macular Degeneration

Macular degeneration has two forms:

  • Dry AMD – This is the more common form of AMD, affecting approximately 90% of those with macular degeneration.  It typically develops slowly and causes mild visual distortion to moderate central vision loss.
  • Wet AMD – This form affects only 10% of people with macular degeneration but causes more severe vision loss. In wet AMD, new blood vessels that form under the macula leak fluid and can cause a rapid and severe loss of central vision.

How Common Is AMD?

Macular degeneration is the most common cause of severe vision loss among individuals over age 65. It’s estimated that over 11 million people in the United States have AMD.

AMD affects about 9% of the population over age 40 and causes vision loss of 20/200 or worse (legal blindness) in 15-20% of those with the condition. 

Age is the greatest risk factor for macular degeneration. Those over the age of 75 have a roughly 30% risk of developing macular degeneration compared to about a 2% risk for people in their 40s.

Other risk factors for macular degeneration include:

  • Smoking
  • A family history of AMD
  • High cholesterol
  • Excessive exposure to sunlight
  • High dietary intake of saturated fat and cholesterol
  • Uncontrolled hypertension
  • A high body mass index in men
  • Race (AMD affects Caucasians more than people of other races)
  • Gender (Women are twice more likely to develop AMD than men)

What Are the Symptoms of AMD?

macular-degeneration-loss-of-sight-in-central-vision-zone

Macular degeneration is painless. However, visual symptoms are constant and limited to the central area of a person’s visual field. These include:

  • Distorted vision
  • Blurred vision
  • A central darkened spot or empty area

Can Macular Degeneration Be Treated?

Macular degeneration, a leading cause of vision loss among older adults, poses significant challenges in treatment, particularly in its advanced stages. But advancements in medical research have led to the development of various treatment options aimed at slowing the progression of the disease, preserving as much vision as possible, and, in some cases, improving sight.

Current treatment options for macular degeneration include:

  1. Anti-VEGF Therapy – One of the most effective treatments for wet AMD involves the use of anti-VEGF (Vascular Endothelial Growth Factor) injections. These medications help reduce the growth of abnormal blood vessels in the eye that cause wet AMD and can even improve vision in some patients.
  2. Laser Therapy – Laser treatment can sometimes be used to treat certain types of wet AMD by destroying abnormal blood vessels in the retina. However, this treatment is less common than anti-VEGF injections due to the potential for damaging surrounding healthy tissue.
  3. Photodynamic Therapy (PDT) – PDT is another treatment for wet AMD, where a light-sensitive drug is injected into the bloodstream, which then gets activated by shining a specific type of laser light into the eye. This helps to seal off leaking blood vessels without harming the surrounding tissue.
  4. Low Vision Aids – For those with advanced macular degeneration (loss of vision due to AMD), various low vision aids and devices can help individuals maximize their remaining vision. These tools include magnifying glasses, special lenses, and electronic devices designed to enlarge or enhance visual information.
  5. Lifestyle Changes and Supplements – While not treatments per se, certain lifestyle changes and nutritional supplements can help slow the progression of AMD. The AREDS2 study, a major clinical trial, found that a specific combination of vitamins and minerals (including vitamins C and E, lutein, zeaxanthin, zinc, and copper) can reduce the risk of AMD progressing to a more severe stage.

Can Macular Degeneration Be Prevented?

holding-eyeglasses-in-one-hand-and-vitamins-in-other

As mentioned earlier, recent research suggests that taking certain antioxidant vitamins and other nutritional supplements may help slow or prevent the development of macular degeneration in some individuals.

Vitamins A, C, and E; zinc; carotenoids; and lutein may be beneficial in maintaining a healthy retina. These substances, however, have not been shown to reverse existing damage to the retina from AMD.

Other actions you can take to lower your risk of AMD include:

  • Getting plenty of exercise
  • Maintaining a healthy weight
  • Eating a balanced diet
  • Avoiding or quitting smoking
  • Taking vitamin supplements daily

Excessive exposure to sunlight is also a risk factor for AMD, so it’s a good idea to wear sunglasses outdoors. Ideally, you want sunglasses that provide 100% UV protection. A wide-brimmed hat also helps limit the amount of UV radiation that reaches your eyes.

Conclusion

While there is currently no cure for macular degeneration, the array of existing treatments combined with emerging therapies offers hope for individuals diagnosed with this condition. 

Patients should have regular check-ups with their eye doctor, who can provide the latest information on treatment options and management strategies tailored to their specific stage of AMD. Early detection and treatment are key to managing macular degeneration and maintaining quality of life.