Our eyes go through several age-related changes over the course of our lives. One such change that some older adults experience is called age-related macular degeneration (AMD).
AMD is caused by the wearing down of the macula, a small part of the retina. It leads to a progressive loss of central vision. Central vision enables us to clearly see colors, details, and shapes. Many people with AMD will eventually be considered legally blind.
Research suggests both genetic and environmental factors may contribute to a person developing AMD, but age appears to be the major component.
We’ll break down the findings, as well as how to spot and treat AMD.
Current research indicates both genetic and environmental factors cause AMD.
Research is still ongoing into how exactly having certain genes makes AMD more or less likely. But there is significant evidence certain gene mutations or gene combinations do increase the risk of AMD (more on this in the next section).
One of the best ways to explore the genetic causes and risk factors of health conditions is to conduct
GWAS allow researchers to collect enormous amounts of DNA samples, then search for connections. They might investigate specific DNA markers for a disease or trait, or look for common markers among multiple conditions to establish risk factors.
A genetic variant refers to a change in a gene that affects its function. This is sometimes called a mutation, especially if it leads to a disease.
GWAS has allowed scientists to identify certain gene variants associated with an increased chance of developing AMD.
A lot of these genes had responsibilities related to coding lipid metabolism (storing and using fats for energy) and the extracellular matrix (cell communication and attachment to other cells).
The American Association of Ophthalmology (AAO) summarizes that research suggests variations in two genes are particularly associated with the development and advancement of AMD.
These are the complement cascade (group of genes) on chromosome 1 and the ARMS2/HTRA genes on chromosome 10.
Overall, data indicates there is a strong genetic component for AMD. GWAS will likely contribute to more gene variants being connected with AMD in the future.
As you can tell by the name, age is the primary risk factor associated with AMD. This is because the macula naturally thins and wears down as you age.
However, not all older adults will experience AMD:
ages 55 and olderare the most likely to have macular degeneration.
- AMD is the leading cause of vision loss and blindness for U.S. adults
65 and older.
- AMD affects around
11 millionpeople in the United States overall. This number is expected to rise, as older adults are an increasingly largerportion of the world population.
Rates of AMD appear to be increasing, but this is in part due to a growing older population.
Researchers have identified several other risk factors for AMD, aside from age and genetics.
- Having drusen. Drusen are clusters made up of lipids and proteins that can build up under your retina’s macula. Having drusen isn’t necessarily a sign of vision loss, but it is associated with an increased risk of developing AMD. Large drusen can impair your central vision, and are considered a defining feature of AMD.
- Race. While the exact reasons remain unclear, researchers have repeatedly found that older white people are at the highest risk of developing AMD.
- Smoking. Being a smoker increases your risk for AMD, alongside multiple other health conditions.
- High blood pressure. High blood pressure (hypertension) is linked to an increased risk of AMD.
- Having obesity. You’re at a higher risk for AMD if you’re overweight or obese.
- Eating a diet high in saturated fats. Foods high in saturated fat include certain dairy products, oils, and processed meats.
There are two types of AMD: wet and dry. Each has a different effect on the eye and treatment options.
Dry AMD is more gradual and less intense than wet AMD, which can cause rapid and sudden vision decline. However, wet AMD is more treatable. Oftentimes, early AMD shows no symptoms.
- blurriness in central vision
- trouble seeing in low light
- straight lines look wavy or crooked (late AMD)
- blank spots in vision
- colors are faded
What is the macula?
The macula is a small part of the retina, the light-sensitive tissue at the back of the eye that allows us to see fine details and color. Other parts of the retina allow us to have peripheral, or side vision.
For example, people with AMD may not see the hands of a clock, but they may still see the clock’s numbers around its edges.
About 80 percent of people with AMD experience dry AMD, according to the AAO. Dry AMD occurs when clusters of a protein called drusen grow and cause thinning or distortion of the macula. With this form of AMD, central vision loss is typically gradual.
The symptoms of dry AMD tend to worsen progressively over time and can be categorized into three stages.
Wet AMD (also called advanced neovascular AMD) is less common than dry AMD. However, it’s considered more serious because it causes faster and severe vision loss.
Wet AMD is always considered late stage, or stage 3, though it can occur at any time. Wet AMD strikes when abnormal blood vessels quickly grow at the back of the eye and damage the macula.
The vision loss caused by dry AMD is permanent, and cannot be reversed. However, there are ways to slow and manage vision loss symptoms in dry AMD, most notably through ARED supplements.
For wet AMD, symptoms can be slowed or stopped. In some cases, vision changes can even be reversed with anti-VEGF injections.
We’ll discuss the above treatment methods more in depth below.
Currently, there’s no way to cure dry AMD, but certain approaches can help manage symptoms.
- Maintaining strong eye health. Schedule regular eye health appointments so your eye doctor can keep tabs on your changing vision. Lifestyle factors, such as eating a balanced diet, getting enough exercise, and quitting smoking, are beneficial for overall eye health. They may help some people with AMD maximize the vision they have.
- AREDS 2 supplement. For people with intermediate AMD in one or both eyes, some eye specialists recommend a special dietary supplement called AREDS 2. The AREDS 2 supplement is made from large amounts of specific vitamins and minerals that are
shownto slow or stall central vision loss in people with AMD.
- Using low vision aids. These tools help you make the most of the vision you have. Some common low vision aids include digital and handheld magnifiers, spectacles, and audio and dictation software.
- Find emotional support. Going through vision changes and experiencing vision loss can be exhausting and difficult. It’s important you have a strong support network. Consider making an appointment with a therapist to provide yourself a safe space to work through your emotions.
Unlike dry AMD, wet AMD is treatable. Treatments can slow or stop vision loss. Sometimes vision changes can be reversed.
- Anti-VEGF drugs. This medication is administered by injection into your eye on a cycle, usually every month. Anti-VEGF drugs help slow or stop the damage caused by the abnormal blood cell growth that causes wet AMD. This can slow or stop vision loss, and in some cases even improve a person’s vision. Learn more about anti-VEGF injection.
- Photodynamic therapy (PDT). You receive an injection of light-sensitive medication in your arm. Your doctor will then target the blood vessels in your eye that are causing wet AMD vision loss with a special laser, which the medication helps break down.
As with dry AMD, people with wet AMD can help cope with vision loss by using low vision aids to help assist with daily tasks.
There are plenty of ways you can keep your eyes healthy in addition to addressing known AMD risk factors.
Tips for better eye health include:
- scheduling regular eye exams
- quitting smoking
- eating a balanced diet (make sure to get in all your vitamins)
- exercising regularly
- getting plenty of sleep
- maintaining healthy blood pressure and cholesterol levels
AMD is treated by doctors called optometrists and ophthalmologists. These professionals specialize in vision and eye disorders. If you don’t have an eye doctor or surgeon yet, your primary care doctor can refer you.
Vision changes of any kind are a cause to talk with your eye doctor. If you have AMD, timely diagnosis can help you manage and potentially treat the condition as soon as possible.
If you suddenly begin to notice that straight lines appear wavy, this may be a sign of late AMD. Call your eye doctor promptly if you experience this symptom.
AMD is a common age-related eye condition that causes the loss of central vision over time. Dry AMD is more common than wet AMD, but it’s less treatable. The main risk factor for both types of AMD is age.
Current and ongoing research indicates there’s a strong genetic component for AMD. This means if you have a blood-related family member with AMD, your risk of developing it may be higher. However, not everyone with a family history of AMD will develop the condition.
While there’s no cure for dry AMD, low vision aids can help you maximize the vision you have. Wet AMD can be treated with anti-VEGF drugs, which help stop abnormal blood cell growth leading to vision loss.
Talk with your doctor if you are experiencing vision change or loss, or if you have questions about your AMD risk factors.