What Causes Macular Degeneration?

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Age-related macular degeneration (AMD) is an eye condition that impacts approximately 12.6% of Americans aged 50 and older. It can cause significant vision changes, including visual distortions, alterations of the visual field, and even blindness. Macular degeneration is actually a leading cause of vision loss among people aged 50 and older in the U.S. It is also the most common cause of blindness in the developed world.

However, while AMD is relatively common, not everyone knows what it involves. AMD is a problem with degeneration of the central part of the retina in the eye, an area called the fovea. When this happens, you can experience central vision loss, which makes it harder to read and drive.

There are two types of AMD, dry and wet. Dry AMD is more common; it’s what 90% of AMD patients have. Dry AMD happens when the layers of the macula on the eye get thinner over time. Wet AMD is when new blood vessels grow behind the retina in the eye and then leak fluid. 

Many people want to know what causes AMD, particularly if it creates opportunities to reduce their risk. Here’s a look at what’s known about the causes of AMD.

Causes of Dry Macular Degeneration

Overall, it isn’t clear what causes dry AMD. According to the Mayo Clinic, research suggests that genetics may play a role, as could environmental factors and lifestyle choices. For example, a person’s diet may influence their chances of developing the condition. Smoking seems to increase the odds that dry AMD will occur, as does being obese. Individuals with cardiovascular disease and atherosclerosis are potentially at a higher risk of developing the condition.

As the name implies, age is also a significant part of the equation. Dry AMD is more common in people aged 60 and older. As a person ages, certain changes in the eye can occur that affect the macula. With dry AMD, as the macula tissues thin and the cells responsible for vision are lost, it can cause vision loss.

Causes of Wet Macular Degeneration

Wet AMD often develops as dry AMD worsens. Therefore, the causes of wet AMD are similar to the causes of dry AMD. 

This condition involves irregular blood vessel growth, which can occur in anyone who has dry AMD. If the blood vessels leak, fluid can build up, leading to macular irregularities that cause visual distortions or vision loss.

The most significant risk factor is typically age, as it becomes more common as people get older. Smoking and obesity may increase someone’s likelihood of developing the condition, as may genetic factors or cardiovascular disease. A person’s diet could also be a factor. Eating antioxidant-rich foods and getting enough omega-3 fatty acids may reduce a person’s risk. As a result, a person not including those in their diet may increase their chances of developing the condition.

Next Steps

The risk of AMD may be unavoidably higher for some people because of the link it has to family history and genetics. But there are also risk factors that are within your control, such as smoking and obesity. The best way to prevent AMD is to make healthy lifestyle choices and visit your doctor for routine eye exams. If you have a family history of AMD, talk to your doctor about how often to get tested and how to reduce your risk with lifestyle changes.  

Further reading:

  1. Ruia S, Kaufman EJ. Macular degeneration. [Updated 2022 Aug 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560778/
  2. Stevens A. “Top causes of vision loss and blindness.” AARP. Published 04 Dec 2020. https://www.aarp.org/health/conditions-treatments/info-2020/causes-of-blindness.html 
  3. Centers for Disease Control and Prevention. “Prevalence of age-related macular degeneration (AMD).” Last reviewed: 31 Oct 2022. https://www.cdc.gov/visionhealth/vehss/estimates/amd-prevalence.html 
  4. American Macular Degeneration Foudnation. “Dry vs wet age-related macular degeneration.” Accessed Mar 2023. https://www.macular.org/about-macular-degeneration/what-is-macular-degeneration/types/dry-vs-wet-macular-degeneration 
  5. Mayo Clinic. “Dry macular degeneration.” Published 23 Nov 2022. https://www.mayoclinic.org/diseases-conditions/dry-macular-degeneration/symptoms-causes/syc-20350375#:~:text=Clinic-,Causes
  6. Mayo Clinic. “Wet macular degeneration.” Published 21 Feb 2023. https://www.mayoclinic.org/diseases-conditions/wet-macular-degeneration/symptoms-causes/syc-20351107