Macular Degeneration: Signs, Symptoms, Treatments
To understand what macular degeneration is, you must first understand the function of the retina’s macula.
The macula is the very center part of the retina, responsible for producing sharp, clear, and focused vision.
The retina is the light-sensitive layer of cells at the back of the eye. The retina detects colors with its specialized cells called cones and rods. It also sends visual signals to the brain through the optic nerve.
The brain then forms the images we see and produces the sense we call sight.
Although many retinal diseases can cause total blindness, macular degeneration rarely results in this. Vision loss is almost always limited to the central visual field, with peripheral vision that is relatively intact.
As its name suggests, macular degeneration affects only the macula. However, it’s still capable of causing serious problems because many activities are highly compromised, especially for the elderly.
Macular degeneration can cause the central visual field to look like a black doughnut hole, making it hard to see. Activities like crossword puzzles, knitting, sewing, reading, and watching television may become extremely difficult, if not downright impossible.
People with this condition may not even recognize the faces of people they know and love. Often abbreviated AMD (and sometimes ARMD), the condition affects one-quarter of females and one-third of males over the age of 75, at least to some degree.
According to the American Optometric Association, the risk of contracting AMD and experiencing its more severe complications rises with age.
For a list of more eye conditions, you can go here.
Types of Macular Degeneration
There are two types of AMD: dry or non-exudative and wet or exudative. The dry form is typically less of a threat to sight and accounts for 80 to 90 percent of all cases of AMD.
Wet AMD and Neovascularization
The wet form affects about 10 to 20 percent of all persons with the condition and is generally more serious. It involves the growth of abnormal blood vessels at the back of the eye, a process called neovascularization.
In medical terminology, the prefix neo means new, and the term vascular refers to blood vessels, hence the name.
The body uses neovascularization to compensate for faulty blood vessels in the retina. When these normal blood vessels begin to fail, the body grows new ones to take their place.
However, these new blood vessels are weak. They bleed and leak fluids into the area, causing further retinal damage. These vessels also commonly grow underneath the macula where no blood vessels are supposed to be, as the retina needs to be flat.
Blood vessels growing underneath the macula may cause straight lines to look wavy. A special chart called the Amsler Grid is a tool people with AMD can use at home to indicate possible AMD and document any worsening.
The Amsler Grid looks like a square with tiny boxes in it and a dot in the middle. All lines should look straight. If they do not, AMD may be the cause.
Dry AMD
Dry AMD occurs when deposits of yellowish proteins called drusen appear in the macula. These proteins may resemble bits of pollen. These deposits are abnormal and can cause retinal damage and loss of function over time.
Drusen are easily seen during a dilated eye exam.
The dry and wet forms tend to gradually produce vision loss over time, but the wet form sometimes causes sudden vision loss.
Symptoms of Macular Degeneration
These generally include disturbances in the central visual field, including shadows and blurry, fuzzy, or distorted areas. When reading, some patients may notice that letters and lines appear to be wavy. For example, when looking at a crossword puzzle, the patient may see columns of wavy lines instead of straight ones.
Low-light vision will tend to worsen, and the person may have greater sensitivity to light.
Symptoms may not be apparent in the early stages of the disease, especially if only one eye is affected or is not as affected as the other. AMD in both forms may occur in one eye or both.
Involvement of both eyes may be more likely when certain factors, especially smoking, cause the condition.
Macular Degeneration Causes and Risk Factors
AMD has several known risk factors, although anyone can get it. The American Academy of Ophthalmology notes that some published risk factors remain unproven, but most studies indicate that smoking and aging are definite risk factors.
You cannot prevent aging, but you can and should stop smoking. Cigarette smoke is toxic to the eyes and raises the risk of both AMD and cataracts.
Macular degeneration is a terrible eye disease that will compromise nearly every aspect of your life. It’s a disease best avoided if at all possible.
Other risk factors in addition to aging and smoking may include:
1. Obesity
2. Gender
3. Cardiovascular disease
4. Family history
Treatment
There is no cure for AMD. However, over the last 20 years, promising AMD treatments have become available.
There are no specific treatments for dry AMD, but special vision supplements containing vitamins E and C, the trace minerals copper and zinc, and the antioxidant compounds zeaxanthin and lutein may help slow disease progression.
AREDS Eye Health Supplements
Some people take these supplements for AMD prevention. While effectiveness has not yet been proven, clinical trials conducted by the National Eye Institute have indicated they may be helpful.
Antioxidants may help to limit, prevent, or even improve AMD by protecting the retinal cells from damage caused by toxic compounds called free radicals. Antioxidants work to neutralize free radicals in the retina and all over the body.
Although there is no conclusive proof these eye health nutritional supplements work, they are not expensive, are unlikely to cause any harm, and contain necessary nutrients needed by the body anyway.
There is some controversy about lutein and zeaxanthin and if they help the retina. However, there is no proof that they can cause any harm when taken as directed.
If you choose to use these supplements, first ask your eye doctor about them. Let them suggest a brand for you to try. You will generally be looking for supplements approved by AREDS, which stands for Age-Related Eye Disease Study.
AREDs is the name referring to several AMD clinical trials conducted by the National Eye Institute.
Other AMD Treatments
For the wet AMD form, the more serious one, effective drugs called biologicals have been developed. Called by their brand names Lucentis, Avastin, or Eyelea, these drugs may inhibit the neovascularization process and preserve or even improve vision.
Success rates for these drugs are fairly high, and the data and results are wonderfully encouraging.
Wet AMD may also be treated with laser therapy to try to seal off leaky blood vessels. However, laser therapy may be limited because it can also worsen vision problems.
AMD patients may also benefit from low-vision devices like magnifiers, telescopes, and apps. Some eye doctors specialize in this field.
One study indicated that those diabetes-related health issues had a higher prevalence of wet AMD than other types of AMD.
Preventing AMD
There is no proven method to avoid AMD. However, regular eye exams will help spot it while it’s still in its early stages and potentially the most treatable.
If you smoke, STOP! It’s one thing you can do to possibly avoid AMD or other serious diseases and improve your health overall.
Get regular eye exams. These should be dilated eye exams, not cursory ones used to check your vision or for new eyeglasses or contact lenses.
A dilated eye exam uses special drops to dilate the pupils so that the eye doctor can get a good view of the retina and spot potential problems as early as possible.
You should also eat a healthy diet, exercise, and protect your eyes from the sun by wearing sunglasses rated for UVA and UVB light.
Find a Top Eye Doctor Near You
If you’re concerned about AMD, especially if you’re over the age of 65, have a family history, or are a current or former smoker, we can help.
Our doctors are all highly qualified and all welcome new patients. If you’d prefer a female or male eye doctor or one in a particular area, just let us know. Our referrals are customized just for your needs.
We look forward to helping you find a great eye doctor.
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