Macular degeneration risk factors: who is more likely to get AMD

What AMD is

AMD happens when aging damages the macula, the part of the retina that controls sharp, straight-ahead vision. It is a leading cause of vision loss for older adults, and about 11 million people in the United States have it. AMD does not cause complete blindness, but losing central vision can make it harder to see faces, read, drive or do close-up work (NEI).

There are 2 types. Most people have dry AMD, where the macula gets thinner with age; it moves through early, intermediate and late stages, usually slowly over several years. Wet AMD is a less common type of late AMD in which abnormal blood vessels grow at the back of the eye and damage the macula; it usually causes faster vision loss. Any stage of dry AMD can turn into wet AMD (NEI) (MedlinePlus).

Who is more likely to get AMD

Your risk goes up as you get older. NEI says people age 55 and older are more likely to have AMD, and that risk is also higher for people who (NEI):

• have a family history of AMD
• are White (NEI uses the word Caucasian)
• smoke

MedlinePlus lists the same 3 and adds 2 more: having high cholesterol and having high blood pressure (MedlinePlus). It says the cause of AMD is unknown and is believed to be a mix of aging, genes and lifestyle factors such as smoking and diet (MedlinePlus). Having late AMD in 1 eye also puts you at higher risk of late AMD in the other eye (NEI).

Age, family history and race cannot be changed. Smoking, blood pressure and cholesterol can. See the quit smoking check, high blood pressure risk factors and high cholesterol risk factors.

Dry and wet AMD risk factors

NEI and MedlinePlus give one list of risk factors for AMD as a whole; they do not give separate lists for dry and wet AMD (NEI) (MedlinePlus). Wet AMD is always late stage, and any stage of dry AMD can turn into it (NEI).

Symptoms

Early dry AMD does not cause symptoms. In intermediate dry AMD some people notice mild blurriness in their central vision or trouble seeing in low light (NEI). In late AMD, wet or dry, you may notice (NEI) (MedlinePlus):

• straight lines that look wavy or crooked
• a blurry area near the center of your vision that may grow, or blank or dark spots
• colors that look less bright
• more trouble seeing in dim light

NEI calls wavy straight lines a warning sign for late AMD: if you notice it, see your eye doctor right away (NEI). MedlinePlus says the same for any sudden change in your vision (MedlinePlus).

How AMD is found

Eye doctors check for AMD as part of a dilated eye exam, sometimes with an imaging test called optical coherence tomography (OCT). Because early AMD has no symptoms, NEI says people at risk because of age, family history or other factors should get regular eye exams and ask their doctor how often (NEI). The vision screening check for older adults covers what the US Preventive Services Task Force says about screening in primary care, which is a different question from an exam by an eye doctor.

What may lower your risk

NEI says research shows you may be able to lower your risk of AMD, or slow vision loss from it, with these choices (NEI):

• quit smoking, or do not start
• get regular physical activity
• keep blood pressure and cholesterol at healthy levels
• eat healthy foods, including leafy green vegetables and fish

MedlinePlus lists the same steps and adds keeping a healthy weight and getting regular eye exams (MedlinePlus).

Common questions

What are the predisposing factors for macular degeneration?

"Predisposing factors" is another way to say risk factors. NEI names age (55 and older), a family history of AMD, being White and smoking (NEI). MedlinePlus also names high cholesterol and high blood pressure (MedlinePlus).

Can AMD be treated?

It depends on the type and stage. There is no treatment for early AMD, so the eye doctor keeps watch with regular exams. For intermediate AMD, special dietary supplements (vitamins and minerals) may stop it from turning into late AMD. For wet AMD, medicines injected into the eye (anti-VEGF drugs) or photodynamic therapy may stop further vision loss. There is currently no treatment for late dry AMD, but low vision devices and vision rehab can help (NEI).

Is AMD related to cataracts or glaucoma?

They are different eye diseases, each with its own list of risk factors. See cataract risk factors and glaucoma risk factors.