What is Macular Degeneration?
Age-related macular degeneration (AMD) refers to an eye disease that can make your central vision blurry. You can develop it as you age due to damage to the macula.
The macula forms part of the retina where light-sensitive tissue lies. It's responsible for sharp, central vision. Macular damage is the leading cause of vision loss in older adults.
While AMD may not result in complete blindness, you can lose your central vision. Partial loss of this field of vision could make it more challenging to distinguish faces, read, drive, or do close-up work like cooking or fixing items around the house.
The severity of AMD can vary from one person to the next. This means that it can develop slowly or quickly. If you experience early AMD, you may not even be aware you have a vision problem for a long time.
Because of this, you should undergo regular eye exams. With early detection, you may be able to prevent or mitigate further macular damage.
There are two types of macular degeneration:
- Dry macular degeneration is the most common, occurring in 85 to 95% of cases.
- Wet macular degeneration is when abnormal blood vessels grow under the macula, leaking fluid and blood. Wet macular degeneration always begins as the dry form.
How to Test for Macular Degeneration
If you believe you have AMD, you should visit your local eye clinic and speak with an eye doctor. You'll undergo a comprehensive eye examination, including various tests, to rule out or diagnose the condition.
Different testing approaches include:
- Amsler Grid
- Retinal examination
- Fluorescein angiography
- Optical coherence tomography
What is an Amsler Grid Test?
The Amsler grid test is one of the many standard tools used to perform a diagnosis. The grid consists of a single square composed of a grid pattern and a black dot in the middle. The test helps identify problem spots in your field of vision.
You can perform the test at home or in your local eye clinic.
How to Use an Amsler Grid Test
If you want to use the Amsler grid test correctly, follow these steps once a day, every day:
- Put on your regular reading glasses if you have them. Hold the grid at eye level an approximate distance of 12 to 15 inches away from your face in good light.
- Then, cover your left eye.
- With your right eye only (uncovered), look right at the dot in the middle and lock your focus there.
- While staring at the center dot with your uncovered eye, pay attention to the grid lines in your peripheral vision. If any lines or areas look blurry, wavy, dark, or blank, speak with your eye doctor.
- After you have done one eye, switch and perform the same tasks with the other eye.
What Does the Amsler Chart Look Like if You Have Macular Degeneration?
A person with macular degeneration won't see the Amsler grid/chart the same way as someone without eye health issues. If you have AMD, the grid could appear to have wavy lines or blank sports.
If this occurs, it is important to speak with an eye doctor immediately. Early diagnosis could help your eye doctor establish a treatment regimen and prevent further damage.
How Effective is an Amsler Grid Chart for Testing Macular Degeneration?
Current best practices will promote the use of an Amsler grid chart to test macular degeneration. However, according to a study, the sensitivity of Amsler Grids can be less than 50%.3
This means that some individuals with macular degeneration may not believe they have the condition when, in reality, they do.
Despite this, the Amsler grid chart is still useful. It's economical and can be performed at home daily. Until another adequate replacement comes about, using amsler grids combined with knowledge of risk factors and clinical history can help with early detection.
If you believe you have AMD, you should visit your eye doctor. You can undergo other tests to help establish a proper diagnosis and start treatment, if necessary.
What Causes Macular Degeneration?
AMD is a complex disease. Researchers and doctors still don't know its exact cause. Some believe that genetic components and environmental factors play a role in your susceptibility to macular damage.
Here are some risk factors:
- Age. The majority of AMD cases happen in people over the age of 50.
- Family history. There are specific genes related to AMD onset.
- Race. Caucasians face an increased risk of AMD.
- Smoking. Smoking or exposure to secondhand smoke raises your likelihood of developing AMD.
- Unhealthy diet. Research suggests that obesity and unhealthy diets may amplify disease severity.
- Cardiovascular disease. You could have a higher chance of developing the wet form of macular degeneration if you have health issues that involve your heart or blood vessels (e.g., high blood pressure or hypertension).
What are the Symptoms of Macular Degeneration?
If you have macular degeneration, your symptoms may vary according to the disease stage. For example, dry AMD has three stages: early, intermediate, and late. Because it's progressive, symptoms tend to get worse as time passes.
Here is the progression of AMD:
- Early. People with early cases of dry AMD won't show symptoms.
- Intermediate. At this stage, some may still not show changes in their visual field. Others may experience mild blurriness in central vision or have trouble seeing in low-lighting settings.
- Late/Wet. Those in this stage may observe a blurry area in their central vision. As time progresses, this blurry area could increase in size, becoming a blind spot. Other effects include dimmer colors, straight lines appearing wavy, and poor vision in low light.
Macular degeneration takes the lead in the main causes of vision loss, affecting more than 10 million Americans.
How to Treat Macular Degeneration
Macular degeneration can't be cured. It's a progressive disease. However, early detection can reduce symptom severity and slow disease progression.
Disease type and stage will determine the kind of treatment you will receive. In general, though, your healthcare provider may consider the following therapeutic approaches:
Clinical trials found that combining vitamin and mineral intake could slow the progression of dry AMD.2 AREDS supplements are vitamins C and E, lutein, zinc, copper, zeaxanthin, and beta carotene (this is not recommendable for smokers due to an increased risk of lung cancer).
Antivascular endothelial growth factor (anti-VEGF)
This is a treatment for wet AMD that includes blocking VEGF production, a protein that contributes to the creation of blood vessels. Your eye doctor will inject anti-VEGF into a numbed eye to delay or stop blood vessel development. Vision could improve as a result.
Photodynamic therapy (PDT)
A healthcare professional will use both an injectable light-sensitive drug and laser treatment to eliminate extra blood vessels in the eye. You may undergo a combination treatment with anti-VEGF.
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