Excellent Eye Care
What is Macular Degeneration?
Macular degeneration, or age-related macular degeneration (AMD) is a leading cause of vision loss in Americans 60 and older. It is a disease that destroys your sharp, central vision. You need central vision to see objects clearly and to do tasks such as reading and driving.
AMD affects the macula, the part of the eye that allows you to see fine detail. It does not hurt, but it causes cells in the macula to die. In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. Regular comprehensive eye exams can detect macular degeneration before the disease causes vision loss. Treatment can slow vision loss. It does not restore vision.
Types of Macular Degeneration
Wet AMD. In wet macular degeneration, abnormal blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive retinal cells (photoreceptors) in the macula and creates a central blind spot (scotoma) in the affected person’s visual field.
Choroidal neovascularization (CNV), the underlying process causing wet AMD and abnormal blood vessel growth, is the body’s misguided way of attempting to create a new network of blood vessels to supply more nutrients and oxygen to the eye’s retina. Instead, the process creates scarring, leading to sometimes severe central vision loss.
Dry AMD. Dry macular degeneration is an early stage of the disease. It appears to be caused by aging and thinning of macular tissues, depositing of pigment in the macula, or a combination of the two processes.
Dry AMD is diagnosed when yellowish spots known as drusen begin to accumulate in and around the macula. It is believed these spots are deposits or debris from deteriorating tissue.
Gradual central vision loss may occur with dry macular degeneration; but usually the visual impairment is not as severe as that caused by wet AMD. However, visual impairment from dry AMD can continue to progress year after year, eventually leading to significant vision loss.
Who is at risk for age-related macular degeneration?
Aging is a primary risk factor for AMD. Each decade of life after age 40 significantly increases one’s risk for the disease. This is one reason why having routine eye exams after age 40 is so important.
Other risk factors for age-related macular degeneration include:
As stated above, recent studies have found that specific variants of different genes are present in most people who have macular degeneration.
Smoking is a major risk factor for AMD. Research has shown that, in some populations, smoking was associated with about 25 percent of AMD cases causing severe vision loss. Another study found that people who live with a smoker have twice the risk of developing AMD.
Researchers have found that people with dry AMD who were obese had more than double the risk of developing advanced macular degeneration, compared with people of normal body weight.
People with dry AMD who perform vigorous activity at least three times weekly reduced their risk of developing advanced AMD, compared with people with dry AMD who were sedentary.
A European study found that high blood pressure may be associated with development of macular degeneration.
Frequently Asked Questions
AMD causes no pain.
AMD blurs the sharp central vision you need for straight-ahead activities such as reading, sewing, and driving. An early symptom of wet AMD is that straight lines appear wavy. The most common symptom of dry AMD is slightly blurred vision. You may have difficulty recognizing faces. You may need more light for reading and other tasks. Dry AMD generally affects both eyes, but vision can be lost in one eye while the other eye seems unaffected. As dry AMD gets worse, you may see a blurred spot in the center of your vision. Over time, as less of the macula functions, central vision in the affected eye can be lost gradually.
In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. AMD is a common eye condition among people age 50 and older. It is a leading cause of vision loss in older adults. And vision lost cannot be restored. That’s why early detection and treatment are so important. Make an appointment with one of our experienced macular degeneration specialists.
The National Eye Institute is conducting and supporting a number of studies to learn more about AMD. For example, scientists are:
- Studying the possibility of transplanting healthy cells into a diseased retina
- Evaluating families with a history of AMD to understand genetic and hereditary factors that may cause the disease
- Looking at certain anti-inflammatory treatments for the wet form of AMD
- This research should provide better ways to detect, treat, and prevent vision loss in people with AMD.
Early treatment of intermediate AMD can delay and possibly prevent the advanced stages of AMD from occurring. When treating Wet AMD, the doctor will prescribe either injectable drug treatments, laser surgery, or photodynamic therapy based on the location and extent of the abnormal blood vessels. In rare cases, submacular hemorrhage displacement surgery may be used.
Once Dry AMD reaches the advanced stage, no form of treatment can prevent vision loss. However, treatment can delay and possibly prevent intermediate AMD from progressing to the advanced stage. The National Eye Institute’s Age-Related Eye Disease Study found that taking certain vitamins and minerals may reduce the risk of developing advanced AMD.