Diagnosis and Treatments for Wet and Dry AMD
Age-related macular degeneration (AMD) may affect your vision as you grow older, causing a blank or blurry spot in the center of your vision. The eye disease is the primary cause of vision loss in people who are 50 or older, according to the American Academy of Ophthalmology.
Which Form Do You Have?
Dry and wet forms of AMD produce similar symptoms but have different causes. Both forms affect the macula, the area of the retina responsible for central and color vision. The retina lines the back of the eye and converts light rays into electrical signals that are sent to the brain via the optic nerve. If cells in the retina are damaged or die, you'll notice blank or distorted spots in your vision.
Most people diagnosed with AMD have the dry form, which occurs when the macula thins and yellow deposits called drusen collect under the retina. The drusen eventually kill the cells in the macula, causing central vision loss.
Leaking blood vessels are responsible for the wet form of the disease. The trouble starts when abnormal vessels begin to grow under the retina. As these new vessels leak blood and fluids, the macula becomes scarred.
What Are the Symptoms of AMD?
AMD symptoms tend to develop very gradually and often aren't noticeable until your central vision is significantly diminished. Fortunately, your eye doctor can detect changes in your macula long before you notice a difference in your vision.
As AMD progresses, you'll lose vision in the very central part of your visual field, but your peripheral (side) vision will remain unchanged. Blurred vision or blank spots will make it difficult to see objects clearly when you look straight ahead. Objects may also appear wavy, or you might notice a decrease in brightness. Central vision loss can make recognizing faces, reading, driving and other everyday tasks difficult.
Who Gets AMD?
Age is a key risk factor in AMD, but it's not the only one. You may be more likely to develop the disease if:
- Other People in Your Family Have Had AMD
- You Have High Cholesterol, Uncontrolled High Blood Pressure or Heart Disease
- Your Meals Often Include Foods That Are High in Saturated Fats
- You Smoke
- You Rarely Wear Sunglasses
- You're Overweight
- You Have Light-Colored Irises
- You're Far-Sighted
- You're Female or Caucasian
How Is AMD Diagnosed?
AMD can often be detected during a simple test at your eye doctor's office. During the test, you'll be asked to look at a grid pattern. Your eye doctor will want to know if the boxes appear the same size; if the lines are straight, blurry or wavy; or if you notice any missing lines or dark areas.
Your eyes will also be dilated to provide your doctor with a clear view of your retina, macula, and optic nerve. If your eye doctor suspects that you have AMD, he may recommend a fluorescein angiography test to evaluate the blood vessels in your retina.
What Types of Treatments Are Available for AMD?
Although there's no way to treat the dry form of AMD, you may be able to slow the progression of the disease by making healthy eating choices, losing weight, quitting smoking, controlling your blood pressure, and wearing sunglasses.
Taking certain vitamins may also slow the disease's progression. Results from the Age-Related Eye Disease Study 2 conducted by the National Eye Institute showed that taking these vitamins can be helpful in some people:
- Vitamin C - 500 mg
- Copper - 2 mg
- Vitamin E - 400 IU
- Lutein - 10 mg
- Zeaxanthin - 2 mg
- Zinc - 80 mg
Several research studies are underway to evaluate new treatments to slow or halt the progression of dry AMD.
Wet AMD treatment targets the leaky blood vessels in your retina using Anti-VEGF or laser treatment. VEGF (vascular endothelial growth factor) is a molecule needed for the growth of new blood vessels. Unfortunately, in some cases, the presence of the molecule may trigger the formation of weak or abnormal vessels. Injecting anti-VEGF into your eye prevents new vessels from developing. Laser surgery may also be used to seal leaky vessels in the macula.
Sources:
American Academy of Ophthalmology: Vitamins for AMD, 5/12/18
American Academy of Ophthalmology: What is Macular Degeneration?, 5/10/19