Wet vs. Dry Age-Related Macular Degeneration (AMD)
Age-related macular degeneration (AMD) is a progressive eye disease that blurs your central vision. It affects around 20 million Americans. While it is the leading cause of vision loss in older adults, per the National Eye Institute, it does not cause total blindness. But you may become legally blind.
There are two types of AMD: wet, or neovascular (involving new blood vessel growth) and dry, or non-neovascular. The main difference between dry and wet macular degeneration is what’s occurring in the eye.
What Happens in the Eye in AMD?
The most common form of AMD (about 80 percent of cases, according to Johns Hopkins Medicine) is dry AMD, in which light-sensitive cells in the macula (part of the retina that processes central vision) gradually break down.
Occurring much less frequently, wet AMD happens when abnormal blood vessels start to grow beneath the retina, leaking fluid and blood into the surrounding area, and causing visual distortion and blurry or blind spots.
Wet macular degeneration always begins with dry AMD, says Mayo Clinic. But dry AMD does not always lead to wet AMD. (Dry AMD does not mean dry eyes; the name just indicates that wet AMD is not present.)
Some of the signs and symptoms of dry and wet macular degeneration are the same or similar. They include dark spots in your vision and distortions or bends in what would normally be straight lines.
Many people with dry AMD in the earlier stages experience no symptoms, or only mild symptoms like slight blurriness in the center of their vision or difficulty seeing in dim light.
Signs and symptoms of dry AMD include the following:
Smudges or dark spots appear in your vision, especially in the morning.
Colors appear faded.
Bright lights are irritating.
You have difficulty adjusting your vision when you go from dark to light environments.
Straight lines appear to bend.
When you read, words tend to disappear.
Signs and symptoms of wet AMD include the following:
Straight lines appear to bend.
You have blurry central vision or a blind spot anywhere in your field of vision.
You have difficulty adjusting your vision when you go from dark to light environments.
You have difficulty seeing fine detail without a very bright light.
You experience trouble with face recognition.
You should schedule an appointment with an eye care professional promptly if you experience symptoms of either dry or wet AMD.
In early stages, dry macular degeneration may not cause symptoms, but an eye doctor can see signs of the disease during an exam. It’s important to get an annual eye exam so it can be caught early on.
Both types of AMD are diagnosed using tests that can reveal changes in the macula and retina. These tests include:
Visual Field Test You will be asked to look at a grid of straight lines with a dot in the middle, called an Amsler grid, to see if any lines look wavy or broken, and if the center dot is obscured.
Eye Exam With Dilation Your doctor will put drops in your eyes that widen your pupils, then observe your retina using a special lens.
Fluorescein Angiography After injecting a yellow dye called fluorescein into a vein in your arm, your doctor can observe the dye as it travels through blood vessels in the eye, revealing any abnormal blood vessels.
Optical Coherence Tomography (OCT) This diagnostic tool takes photos of the back of the eye, including the retina and macula. No dye or other medication is necessary.
Optical Coherence Tomography Angiography Using the OCT device, this imaging method uses laser light reflection in place of fluorescein to produce images of blood flow through the eye.
There are certain factors beyond your control that may heighten your risk for either type of AMD:
Age Signs of AMD occur in 14 percent of people ages 55 to 64, in 20 percent of those ages 65 to 75, and in around 40 percent of people over 75.
Gender AMD occurs more often in women than in men.
Race AMD is more common in white people.
Eye color People with blue eyes are at heightened risk.
History of AMD If you have AMD in one eye, your risk of developing it in the other eye is higher, and the risk of the second eye developing wet AMD is greater.
While there isn’t much you can do about your genetic lottery ticket, there are steps you can take to minimize your risk of developing AMD:
Follow a healthy diet.Eat lots of vegetables and fruits and reduce your consumption of saturated fats and processed foods. One study found that participants who ate a Mediterranean-type diet had a lower risk of progression to late AMD. Fish consumption was also important.
Lose excess weight. Obesity can increase your risk for dry AMD, according to a research review.
Maintain healthy blood cholesterol and blood pressure levels. High cholesterol and high blood pressure are not only bad for your heart, but for your eyes as well.
Protect your eyes from UV rays and blue light. Ultraviolet and blue light from the sun and electronics can damage the retina. Wear UV protected sunglasses when you’re outdoors, and reduce blue screen light by using blue light filters on your computer.
Get regular eye exams. The American Academy of Ophthalmology recommends that most adults get a complete eye exam starting at age 40, and that adults ages 65 and over get a full exam every year or two (depending on what eye conditions you have). Prompt detection of AMD, and other eye conditions, can help you get the treatment you need to slow or stop vision loss.
There are currently no treatments for early stages of AMD. Your best bet is to follow the preventive strategies listed above and get regular eye exams.
For intermediate-stage dry AMD, certain supplements called AREDS2 can slow the progression of the disease. The second Age-Related Eye Disease Study (AREDS2), sponsored by the National Eye Institute, found that a formulation of vitamins C and E, copper, lutein, zeaxanthin, and zinc reduced the progression of intermediate AMD to advanced AMD by 25 percent and reduced vision loss by 19 percent. If you’ve been diagnosed with AMD, ask your doctor if AREDS2 supplements could help you.
In 2023, two new drugs were approved in the United States for the treatment of advanced dry AMD (known as geographic atrophy). These treatments — pegcetacoplan (Syfovre) and avacincaptad (Izervay) — are given by injection into your eye in an office procedure, either monthly or every other month. While these drugs have been shown to help slow the progression of advanced dry AMD symptoms, they won’t reverse existing symptoms or completely stop your vision from getting worse.
Wet AMD is treated primarily with injections of antivascular endothelial growth factor (anti-VEGF) drugs, which can stop the growth of new, abnormal blood vessels in the macula. The treatment requires repeated, sometimes monthly, injections into the eyes.
If you do end up with low vision, all is not lost. A variety of aids can help you read, write, tell time, and identify objects. A low-vision specialist can help you identify which aids might help and how to use them. Options include:
Optical magnifying glasses or telescopes
Electronic magnifying devices
Voice recognition and text reading software
Large-print books and publications
Talking clocks, phones, and watches
You may also benefit from seeing health professionals who can help you adapt to your vision limitations — such as learning new ways to do daily activities with an occupational therapist, or dealing with the psychological challenges of vision loss with a counselor. A support group for people with vision loss may also be an option in your area.
