Age Related Macular Degeneration
What Do You Need to Know About (AMD)
More than 15 million older adults in America are affected by some form of macular degeneration, a progressive disease which can lead to severe central vision loss in the most advanced form, end-stage AMD. Approximately 2 million Americans have advanced forms of AMD with associated vision loss, which is the leading cause of irreversible vision loss and legal blindness in individuals over the age of 60. Age-Related Macular Degeneration
Although AMD does not cause complete blindness, it robs individuals of their straight-ahead vision, resulting in what is often referred to as a central vision “blind spot”. While AMD does not affect the outer circle of peripheral vision, hence a person will always be able to see things to the side, this vision is too low resolution (blurry) to make up for lost central vision.
For many people, the first sign of AMD is something they notice themselves. Straight lines like doorways or telephone poles may appear wavy or disconnected. When they look at a person, their face may be blurred while the rest of them are in focus. Lines of print may be blurred in the center or the lines may be crooked.
How is AMD Diagnosed?
As the National Eye Institute explains, the early and intermediate stages of AMD usually start without symptoms. Only a comprehensive dilated eye exam can detect AMD. The eye exam may include:
- Visual acuity test: This eye chart measures how well you see at distances.
- Dilated eye exam: This provides a better view of the back of your eye.
- Amsler grid test: This checks whether you are seeing unusual wavy lines.
- Fluorescein angiogram: This test makes it possible to see leaking blood vessels, which occur in a severe, rapidly progressive type of AMD.
- Optical coherence tomography: Like an ultrasound, OCT can achieve very high-resolution images of any tissues that can be penetrated by light—such as the eyes.
During the exam, your doctor is looking for drusen, which are yellow deposits beneath the retina. Most people develop some very small drusen as a normal part of aging. The presence of medium-to-large drusen may indicate that you have AMD. Another sign of AMD is the appearance of pigmentary changes under the retina.
Wet and Dry AMD:
Dry AMD, also called atrophic AMD, is the most common form of age-related macular degeneration and it can be a very slow progression. Macular Degeneration Partnership explains that it occurs when the there is a “breakdown or thinning of the layer of pigment epithelial cells (RPE) in the macula. These RPE cells support the light sensitive photoreceptor cells that are so critical to vision.” As these cells die and drusen build up, the macula is damaged, reducing central vision.
Wet AMD, also called neovascular AMD, is only diagnosed in about 10 percent of patients, according to the National Institutes of Health. Vision loss associated with wet AMD occurs when abnormal or very fragile blood vessels grow under the macular and then leak blood and fluid. This damages the macula. Typically, patients who develop wet AMD often are diagnosed with dry AMD, first.
Treatments for Wet and Dry AMD vary and an ophthalmologist will recommend specific treatments based on severity. For more information about AMD, visit http://www.centrasight.com/about_amd
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