Let's Talk About Wet Age-Related Macular Degeneration
A subset of one of the most widespread causes of vision loss in people over 50, this disease is serious, but treatable. Here’s what to know about wet AMD, so you can protect your eyesight now and in the future.by Erin L. Boyle Health Writer
Maybe you had dry age-related macular degeneration (AMD) for years and all seemed fine. You had no symptoms until one day everything went blurry in your eyes. Or maybe you suddenly started noticing how the lines of common objects were getting distorted in your house. And as you read, you felt like you were literally losing letters on the page. It could be, you have wet AMD. Here’s what you should know about it.
Our Pro Panel
We went to some of the nation’s top retina specialists in ophthalmology to bring you the most up-to-date information possible.
Jason Hsu, M.D.
Retina Specialist, Attending Surgeon
Wills Eye Hospital
Raj Maturi, M.D.
Retina Specialist, Clinical Associate Professor
Indiana University School of Medicine
Timothy G. Murray, M.D.
American Society of Retina Specialists
Dry age-related macular degeneration is the early form of AMD that has minimal to no symptoms and is slow to progress. Wet AMD is the serious, fast-progressing form of the disease, with symptoms that limit your central vision.
Think of anything you use central vision for, and it’ll be affected by these symptoms of wet AMD (this list is not exhaustive—there are more symptoms, but these are common ones): Blurring; distortion of lines; loss of some colors; loss of some words while reading.
You might have heard about taking vitamins for eye health. If you had dry AMD, your doctor might have put you on AREDS2, a formulation that includes lutein and zeaxanthin and has been found to reduce the progression of dry AMD by 25%. But by the time you’ve progressed to wet AMD, they’re likely not as effective.
Yes—while there is currently no treatment for dry AMD (though numerous clinical studies for potential treatment are in progress), there is treatment for wet AMD. And luckily, it’s very effective. Called anti-VEGF therapy, the important thing to know about this medication is it’s injected into your eye on a regular basis by a highly trained eye doctor.
Age-Related Macular Degeneration, Refresh
Age-related macular degeneration, or AMD, is a leading cause of irreversible vision loss for people age 50 and older in the U.S. It’s estimated that as many as 14 million Americans have some form of this eye disease, and 196 million people worldwide. As the population gets older, the number grows: By 2050, the disease is expected to affect nearly 22 million Americans.
Here's how the eye works: The front part of your eye is called the cornea. That’s the central transparent area of the eye that covers the iris and pupil and is attached to the sclera or the white part of the eye. The sclera is covered by a thin transparent membrane called the conjunctiva. The iris is the colored part that controls the pupil, and pupil is the round, black part that changes shape according to how much light your eye is exposed to.
Behind the cornea and iris, there is the center part cavity of your eye, which is filled with something called vitreous gel. Go beyond that to the back of the eye and there’s the retina, a thin layer of light-sensitive nerve tissue. It plays a big role in sight: Light reaches the retina from the front of your eye, (You may want to mention that light is focused on to the retina by an inner lens that is located behind the iris) the retina changes it to electrical impulses and passes those along to the optic nerve, which in turn sends the impulses to your brain so you can see.
Inside the retina is a small, central area called the macula. The macula is responsible for what you can see when you look directly in front of you, as well as the ability to discern fine detail and color.
Macular degeneration refers to a group of conditions that cause damage to your macula. AMD is one of those conditions, and as the “age-related” terms implies, the disease typically happens in people who are older. You can have AMD in both eyes or just one, and the status of the disease can progress in one eye and not the other.
Understanding Wet AMD
Wet AMD is a progression from dry AMD, an early-stage form of AMD. The hallmark of dry AMD is something called drusen, deposits that form under the retina.
Most people over the age of 50 have drusen deposits in their eyes. Drusen that have well defined edges are called hard drusen and drusen that have unclear edges and often cluster together are called soft drusen. Larger, soft drusen are at higher risk for progressing to wet macular degeneration. They become a problem in higher numbers (20 or more) or larger size and are exacerbated by factors like inflammation in the body.
Drusen disrupt retinal pigment epithelium (RPE) cells, the caretakers and protectors of the eye’s photoreceptor cells, which are key to vision. As a result, RPE cells and photoreceptor cells degrade, causing the eye disease to progress, possibly to wet AMD.
Here’s what happens in wet AMD:
RPE and photoreceptor cells in your eye steadily deteriorate, which allows abnormal, leaky blood vessels to grow from their normal location into an area behind the retina.
This invasion of new blood vessel growth is known as choroidal neovascularization, or CNV, and is marked by blood vessels that are weak and fragile. They leak fluids, lipids, and blood into the macula, which is the most sensitive part of the retina that controls our central vision.
This leaked fluid or blood causes scarring, kills cells, and obscures central vision in the macula.
This all sounds bad—and it is serious. Once one eye has CNV, your second eye is at high risk for the same occurring. But there’s good news. A treatment called anti-VEGF therapy helps prevent the growth of new blood vessels by blocking vascular endothelial growth factor (VEGF), a compound involved in new vessel creation. Anti-VEGF treatment has been used in cancer therapy too—it targets the same creation of new blood vessels caused by growing cancerous tumors.
And it’s effective: Research shows that following two years of anti-VEGF treatment, more than 95% of people with wet AMD maintained their vision, while up to 40% experienced slight improvement in sight.
So it’s treatable. But what causes it in the first place?
Risk Factors for Wet AMD
While the roots of the disease are still being explored, it appears oxidative stress and inflammation play an important role, as does genetics. Scientists have also identified several risk factors that increase your odds of developing AMD in general, including wet AMD:
Age. Those 50 years and older are more likely to have AMD, and the risk goes up as you approach 80. Approximately 17% of people 55 to 64 have AMD; 37% of those 75 or older have the disease.
Smoking/exposure to secondhand smoke. A seminal study in the medical journal Review of Ophthalmology called smoking the “single most important modifiable environmental risk factor” for all forms of AMD. Quitting can help stop the progression of wet AMD. Also, since the toxins in tobacco products are in the smoke itself, if someone in your home smokes, you’re breathing in the AMD-triggering chemicals.
Race. AMD is a disease that occurs predominately in Caucasian people—the National Eye Institute reports that 89% of Americans with AMD are white. Black and Hispanic American populations each account for about 4% of AMD cases, respectively.
Genetics. Your risk of developing the disease is at least three-fold higher if you have a family member with it. One study found that risk increases 27.8 times if your parent has the disease, and 12 times if your sibling has it.
Along with these known risk factors, there are others that could play a role, including:
Sex. On average, women live longer than men, so they’re more likely to have this age-associated disease—nearly twice as likely by some reports.
Diet. A diet low in certain nutrients, including lutein, zeaxanthin, and antioxidants, might lead to increased risk of AMD. You’ll get plenty of these nutrients and others by following a Mediterranean diet, rich in leafy green vegetables and fish, which was associated with a 41% reduced risk of advanced AMD in a recent study.
Weight. Losing weight, having a healthy blood pressure, good heart health, and lower cholesterol levels, are vital to reducing AMD risk factors as you age.
High blood pressure.
Symptoms of Wet AMD
They can come on gradually, or suddenly—with an abrupt onset, as they say in medical-ese. But no matter how you start having symptoms of wet AMD, they’re definitely noticeable. They can include:
Blurriness. Everything in front of you seems blurry, no matter how hard you try to focus. But you can see fine out of the sides of your eye, called your peripheral vision.
Blind spots. Sometimes, pieces of an image in front of you can disappear.
Distortion of straight lines. If you look at, say, blinds in your house or the frame around your door, and they appear wavy even though you know they are straight.
Loss of colors. You tend to retain blue, green, and red, but other colors are harder to perceive.
Hallucinations. When portions of your vision are compromised, sometimes your brain fills in the blank spots with images of its own creating. This most often happens in advanced wet AMD cases and is known as Charles Bonnet syndrome.
Difficulty seeing faces. You might not be able to see part of a person’s face or struggle to recognize someone you know well.
Loss of letters while reading. You’ll be reading along and suddenly, you can’t see the letters right there on the page. (You might see “le ers” instead of “letters”.) If you position your head differently or move the page, the letters appear again.
Diagnosing Wet AMD
To determine if you have this disease, your ophthalmologist will conduct two forms of tests:
Eye exam: After your pupil is dilated by drops, your doctor will use a slit lamp (a microscope with a bright light) to see through your dilated pupil to the back of your eye. It’s a familiar set-up: You sit at a table, place your chin in a stand and your forehead against a strap to steady your head, and your doctor focuses that bright light into your eye. Then he or she looks through the microscope to see your eye in layered detail for signs of wet AMD.
Imaging test: Your doctor will use an imaging device to take highly detailed images of your retina to determine how advanced your AMD is. These can include:
Optical coherence tomography (OCT): An imaging test that uses light waves to take super-fast, highly accurate pictures of your retina. If you’re diagnosed with wet AMD, your doctor may continue using OCT imaging to track how the blood vessels in your eye are responding to treatment. OCT is noninvasive, quick, and painless.
Fluorescein angiography (FA): A special camera that takes rapid, sequential pictures of the blood vessels and other structures of your retina after fluorescein dye is injected into an arm vein and then circulates in your eye, highlighting the blood vessels.
Indocyanine green angiography (ICGA): A diagnostic procedure that uses ICG dye, also injected into an arm vein, to examine the blood flow in the choroid—the layer of blood vessels that lies underneath the retina. This test is different from FA because it can show leaks under a layer of blood—fluorescein can’t.
If you are diagnosed with wet AMD, know this: The treatment for AMD is so effective, it is highly unlikely that you will go blind—and you may even regain some sight you’ve lost.
If you don’t have treatment, however, or if you skip follow-up treatment visits, your risk of vision loss rises significantly. Wet AMD causes 90% of all vision loss related to AMD.
So what is this treatment we keep talking about? Read on.
Wet AMD Treatment
The most common medications given for wet AMD are known as anti-VEGF agents, a class of drugs that includes:
The drug Avastin (bevacizumab) has also been used “off-label” for treatment. Typically, the drug is used for treating cancers including colorectal and lung, but also helps prevent new blood vessel growth in wet AMD.
These are intravitreal medications, given by an injection into your eye. Based on your specific needs, you’ll receive a dose of this medication anywhere from every 4 weeks to every 6 months, or longer.
Before you flip at the idea of a needle in your eye, know this: A trained eye doctor gives the injection—usually a single shot—in a matter of seconds. Many ophthalmologists use a numbing agent first, and you should feel no pain (possibly slight pressure). The medication is given through the side of your eye typically, meaning you don’t see the needle.
If you have any worries, fears, or concerns, talk to your doctor about them before the first treatment. So often, your eye doc will anticipate anxiety before anti-VEGF treatment—this isn’t their first time treating a patient, likely, and after all, who wouldn’t be concerned about having a needle put in their eye?—so express what you’re feeling to them. They can help you through the process with tips and tricks, like having you squeeze a stress ball, holding the hand of a willing assistant, or gripping the arm of your chair as they inject the drug.
Another treatment for wet AMD, photodynamic therapy, can help control the blood vessel growth and bleeding. It’s often effective when combined with anti-VEFG treatment. With this treatment, your doctor will inject the drug Visudyne (verteporfin) into a vein in your arm. This illuminates the blood vessels in your eye, which are then treated with a laser.
Wet AMD Progression
Virtually no disease is static, and your condition can worsen over time. You’ll want to know what to be on the lookout for, so you can talk with your doc about what’s happening and make changes in your treatment plan accordingly. Here are some ways you can monitor your vision to prevent further wet AMD progression:
Check your sight. Use an Amsler grid (the common AMD visual test, showing a grid with a dot in the center) as the screensaver on your computer, or as the backdrop on your tablet. Distorted grid lines or inability to see the dot means it’s time to talk with your doctor.
Understand wet AMD symptoms. Blurriness and loss of vision, particularly in the center of your line of sight, can be the major indicators of wet AMD—it’s what you need to be on the look-out for, in both eyes.
Call your doctor if you experience lasting changes. If you notice a sudden visual distortion or blurriness, give it 24 hours. Still a problem after that time? Call your eye doctor and ask for an urgent exam.
No one is going to tell you dealing with wet AMD is easy (at least, no one who has it or has witnessed a loved one deal with the condition). But as far as treatable diseases go, wet AMD is a pretty safe bet for responding to aggressive and consistent care. Regular self-testing is key, and so is sticking with your appointments—try to see it as your badge of courage: You are all the more legend among family and friends for being shot, literally, in the eye.
Wet AMD and Definition: BrightFocus Foundation. (n.d.) “What Causes Macular Degeneration?” brightfocus.org/macular/causes
Dry AMD: American Macular Degeneration Foundation. (n.d.) “Dry vs Wet Age-Related Macular Degeneration.” macular.org/dry-vs-wet-macular-degeneration
AMD and Drusen: Investigative Ophthalmology & Visual Science. (2003). “Drusen-Related Degeneration in the Retina.” iovs.arvojournals.org/article.aspx?articleid=2182253
AMD and RPE: Johns Hopkins Medicine. (n.d.) “Macular Degeneration.” hopkinsmedicine.org/wilmer/conditions/mac_degen.html
Wet AMD and Both Eyes: JAME Ophthalmology. (1997). “Risk Factors for Choroidal Neovascularization in the Second Eye of Patients With Juxtafoveal or Subfoveal Choroidal Neovascularization Secondary to Age-Related Macular Degeneration.” jamanetwork.com/journals/jamaophthalmology/article-abstract/642161
Wet AMD and Age: American Academy of Ophthalmology. (n.d.) “Age-Related Macular Degeneration.” aao.org/bcscsnippetdetail.aspx?id=9711f063-ed7b-452b-8708-c4dad0d893e8
Wet AMD and Smoking: Review of Ophthalmology. (2006). “The Biology of Smoking and AMD.” reviewofophthalmology.com/article/the-biology-of-smoking-and-amd
Wet AMD and Secondhand Smoke: Centers for Disease Control and Prevention. (2018). “Health Effects of Secondhand Smoke.” cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/health_effects/index.htm
Wet AMD and Race: National Eye Institute. (2019). “Age-Related Macular Degeneration (AMD) Data and Statistics.” nei.nih.gov/learn-about-eye-health/resources-for-health-educators/eye-health-data-and-statistics/age-related-macular-degeneration-amd-data-and-statistics
Wet AMD and Mediterranean Diet: Ophthalmology. (2019). “Mediterranean Diet and Incidence of Advanced Age-Related Macular Degeneration.” aaojournal.org/article/S0161-6420(18)30721-8/fulltext
Wet AMD Symptoms: National Eye Institute. (2019). “Age-Related Macular Degeneration.” nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/age-related-macular-degeneration
About VEGF: University of Rochester Medical Center. (n.d.) “Vascular Endothelial Growth Factor.” urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=vegf
Wet AMD Treatment: American Academy of Ophthalmology. (2019). “How is AMD Treated and Diagnosed?” aao.org/eye-health/diseases/amd-treatment
AREDS2: Ophthalmology. (2012). “ The Age-Related Eye Disease Study 2 (AREDS2): Study Design and Baseline Characteristics (AREDS2 Report Number 1).” ncbi.nlm.nih.gov/pmc/articles/PMC3485447/
Wet AMD and Vision Check: American Macular Degeneration Foundation. (n.d.) “Amsler Chart to Test Your Sight.” macular.org/amsler-chart