What is age-related macular degeneration?
Age-related macular degeneration (AMD) is the leading cause of severe vision loss among older Americans, more than glaucoma and cataracts combined. AMD is most likely to occur in those 50 and older.
AMD is the deterioration of the macula, the small central area of the eye’s retina responsible for sharp, central vision. It has three stages: early macular degeneration, intermediate macular degeneration, and late macular degeneration.
- Early macular degeneration – Early macular degeneration is diagnosed by the presence of medium-sized drusen, yellow deposits beneath the retina about the width of an average human hair. People with early macular degeneration typically do not have vision loss.
- Intermediate macular degeneration – People with intermediate macular degeneration usually have large drusen, pigment changes in the retina, or both. There may be some vision loss at this stage, but most people will not experience any symptoms.
- Late macular degeneration – In addition to drusen, vision loss from damage to the macula will also become noticeable in this stage.
There are also two basic types of macular degeneration: dry and wet.
- Dry macular degeneration – This is the more common type of macular degeneration. With dry macular degeneration, the tissue of the macula gradually becomes thin and stops working correctly.
- Wet macular degeneration – Wet macular degeneration is less common but much more severe. Wet macular degeneration occurs when fluids leak from newly-formed blood vessels under the macula, causing scarring of the macula. Vision loss progresses faster than it does with dry macular degeneration.
What are the symptoms and signs of AMD?
In the early stages, signs and symptoms of AMD can go unnoticed. However, early signs of vision loss from AMD can include:
- The gradual loss of ability to see objects clearly
- The loss of clear color vision
- Objects appear distorted or fuzzy
- A dark or empty area in the center of vision
What causes AMD?
The exact cause of AMD isn’t known. However, genetic and environmental factors may play a role in the development of AMD. The development of AMD is also more likely if a person is:
- Overweight
- A smoker
- Caucasian
- Female
- Has a family history of macular degeneration
- Eats a diet high in saturated fat
What is it like to see through the eyes of someone with AMD?
AMD creates a loss of vision in the center of the eye. As a result, you cannot see fine details. Tasks like cooking, reading, and even having a simple conversation with someone can become difficult. In addition, straight lines like sidewalks and doorframes will appear warped. To better understand AMD’s effect on sight, use the Vision Simulator at versanthealth.com/visionsimulator.
How is AMD diagnosed?
Regular eye exams are essential for maintaining healthy eyes and vision since people may not experience vision loss in the early stages of the disease. Eye care professionals often detect early signs of AMD before symptoms occur. A dilated eye exam may include the following:
- Visual acuity test – This eye chart measures how well you see at distances.
- Dilated eye exam – Your eye care professional will place drops in your eyes to widen or dilate the pupils, which provides a better view of the back of your eye. Using a special magnifying lens, they will look at your retina and optic nerve for signs of AMD.
- Amsler grid – Your eye care professional may also perform a brief test using an Amsler grid that measures your central vision. Changes in your central vision may cause the lines in the grid to disappear or appear distorted, which is a sign of AMD.
- Fluorescein angiogram – If your eye care professional detects some defect in your central vision, such as distortion or blurriness, they may order a fluorescein angiography. In this test, a fluorescent dye is injected into your arm to examine the retinal blood vessels surrounding the macula. This process makes it possible to see leaking blood vessels, a symptom of rapidly progressive AMD.
During the exam, your eye care professional will look for drusen. While most people develop some very small drusen as a normal part of aging, medium-to-large drusen may indicate that you have AMD.
Another sign of AMD is the appearance of pigment changes in the retina. As these cells break down and release their pigment, your eye care professional may see dark clumps of released pigment and less pigmented areas.
How do you treat AMD?
There is currently no known cure for AMD. However, some treatments and lifestyle changes, like exercising, avoiding smoking, and protecting your eyes from ultraviolet light, may help prevent dry macular degeneration’s progression to the wet form.
Wet macular degeneration can be treated with laser treatment if detected early. Another option is photodynamic therapy, used with FDA-approved drugs to stop abnormal blood vessel growth.
Sources:
- https://www.allaboutvision.com/conditions/amd.htm
- https://www.aao.org/eye-health/diseases/amd-macular-degeneration
- https://www.macular.org/what-macular-degeneration
- https://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/macular-degeneration
- https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/age-related-macular-degeneration
- https://preventblindness.org/february-age-related-macular-degeneration-amd-low-vision/
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