What is Dry Macular Degeneration?
Dry macular degeneration is a type of age-related macular degeneration (AMD), the leading cause of vision loss in Americans over 65.1
Dry macular degeneration, also called atrophic AMD, targets central vision and distorts the vision field responsible for seeing straight ahead. It is not painful and does not affect peripheral vision (side vision).
Macular degeneration results from a damaged macula, typically caused by age. The macula is part of the retina located at the back of the eye. It is responsible for central vision, color vision, and sharpness. The macula also helps the retina detect light.
There are three stages of dry macular degeneration: early, intermediate, and late.
Because the disease progresses over several years, early and intermediate stages typically don't produce symptoms. Late-stage symptoms include blurry vision, blank spots, and trouble seeing in low light.
While there is currently not a cure for dry macular degeneration, there are steps you can take to slow disease progression. People with AMD typically don't experience complete blindness because the condition does not affect peripheral vision.
Dry vs. Wet Macular Degeneration
There are two types of AMD: dry and wet.
Dry macular degeneration is the most common type of AMD caused by the thinning of the macula. It is considered less severe than wet AMD.
Wet AMD, also called advanced neovascular AMD, results in faster vision loss and is considered a late form of dry macular degeneration. It is caused by abnormal blood vessels in the back of the eye that damage the macula.
About 10% of people with dry AMD will develop wet AMD. Wet AMD is treated with a combination of injections and laser therapy.3 Both forms of AMD can occur in one or both eyes.
What are the Symptoms of Dry Macular Degeneration?
Early and intermediate stage dry macular degeneration typically doesn't have symptoms. However, delayed eye adjustment to dark places and a change in contrast sensitivity can be early signs.
Because the disease slowly progresses over time, symptoms of severe vision loss don't occur until it has moved into late-stage or wet AMD.
The symptoms of late stage dry macular degeneration include:
- Blurry central vision
- Inability to see fine details
- Trouble seeing in low light
- Straight lines look wavy
- Blind spots in vision
- Colors are less bright
Changes in central vision can affect reading, driving, and identifying faces and everyday objects.
Seeing wavy and crooked lines in your central vision are classic signs of late-stage AMD. Seek medical treatment right away if you experience any of these symptoms.
What Causes Dry Macular Degeneration?
While it isn't clear exactly what causes macular degeneration, age is a leading factor. Over time, the macula starts to thin, leaving the retina vulnerable to damage and central vision loss.
In addition to age, family history, and lifestyle, environmental factors also play a role in the progression of dry macular degeneration.
Who is at Risk for Dry Macular Degeneration?
People over the age of 60 are at a higher risk for developing age-related macular degeneration.
Controllable risk factors include lifestyle and environmental factors that increase a person's chances of developing AMD. These include:
- Cardiovascular disease
- High blood pressure
- Sun exposure without eye protection
- Poor diet
Genetics and family history are uncontrollable risk factors that can lead to AMD. Other uncontrollable risk factors include:
- Light-colored iris (color part of the eye)
- Hyperopia (farsightedness)
- Being female
- Being caucasian
- High levels of C-reactive protein (CRP)
Complications of Dry Macular Degeneration
While the progression of dry macular degeneration is different for everyone, it can lead to complications if not properly managed. Possible complications include:
- Progress into wet AMD
- Charles Bonnet syndrome (visual hallucinations)
- Retinal detachment (medical emergency)
- Anxiety and depression
- Injuries from falls
Alert your eye doctor right away if you are experiencing any AMD-related complications.
When to See a Doctor
Vision naturally changes with age, but specific changes in vision should prompt a visit to the eye doctor right away. These early warning signs include:
- Sudden changes in vision
- Blind spots
- Double vision
- Halos around light
- Wavy lines
- Colors look faded
Routine eye exams can catch eye disorders early, help decrease severe symptoms, and stop the progression of vision loss.
Age-related macular degeneration is diagnosed during a comprehensive eye exam.
After dilating the eyes, an ophthalmoscope is used to examine the retina for a substance called drusen, which are tiny pebbles of proteins that the eye's immune cells do not adequately dispose.
Drusen, seen as white or yellow spots on the retina, is the diagnosing factor for macular degeneration.
A series of other eye exams may diagnose and stage AMD. These can include:
- Amsler grid is a piece of graph paper used to determine if wavy lines are present in the central field of vision.
- Optical coherence tomography (OCT) provides detailed images of the retina and macula.
- Fluorescein angiography is an intravenous dye that highlights the presence of abnormal blood vessels.
While there is no cure for AMD, specific vitamins and dietary supplements can help stop dry macular degeneration from progressing into wet AMD.
The Age-Related Eye Disease Study 2 (AREDS 2) found that a combination of the following antioxidant vitamins and supplements can help reduce the progression of dry AMD by 25%:8
- Vitamin C
- Vitamin E
Along with the AREDS 2 formula, a medical professional may suggest the following dietary and lifestyle changes to slow the progression of dry AMD:
- Eating fruits and leafy vegetables, which are high in antioxidants, vitamins, and minerals
- Eating fatty fish, such as tuna, salmon, sardines, and mackerel, which are high in omega-3s
- Stopping smoking
- Controlling hypertension
- Avoiding processed foods
- Wearing sunglasses
Treatment is different for wet AMD because it involves the growth of abnormal blood vessels.
Gold standard wet AMD treatments include:
- Anti-vascular endothelial growth factor (Anti-VEGF) medications, which are injected into the eye to reduce abnormal blood vessel growth
- Laser surgery to reduce the number of abnormal blood vessels
- Photodynamic therapy (PDT), which uses a laser with dye to target abnormal blood vessels
Depending on disease progression, these treatments might be administered several times over the course of a person’s lifetime to help prevent further vision loss.
While vision loss caused by AMD is not reversible, specific low vision aids are available to help people adapt to low light and central vision changes, including:
- Magnifying glasses
- Reading lamps
- Large font reading material
- Closed-circuit television that magnifies the screen
- Computer tablets
Vision specialists are also available to help people learn to live with vision loss, remain independent, and provide vision rehabilitation.
Can You Prevent Macular Degeneration?
Routine, comprehensive eye exams that include eye dilation are best for catching AMD early and slowing vision loss.
While genetics and family history can't be changed, many dietary and lifestyle changes can slow the progression of AMD, including:
- Vitamins and dietary supplements
- Not smoking
- A healthy diet
- Lowering blood pressure
- Wearing sunglasses and eye protection
- Maintaining a healthy weight
Age-related macular degeneration is a leading cause of serious vision loss among adults over 60. It is caused by the thinning of the macula and the growth of abnormal blood vessels. While it targets central vision, it typically does not affect the peripheral (side) field of vision.
There are two types of AMD: dry and wet. Early stages of dry macular degeneration typically don't have any symptoms until it progresses into the late stage. Late-stage dry AMD symptoms include wavy lines, blurred vision, blank spots, and color fading.
In some cases, dry AMD can lead to wet AMD, which involves the growth of abnormal blood vessels accompanied by faster vision loss.
Dry AMD is treated with vitamins and dietary supplements, and wet AMD is treated with eye injections and laser surgery.
The best ways to prevent AMD are quitting smoking, maintaining a healthy diet, lowering blood pressure, and scheduling routine eye doctor visits.
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