Glossary - Macular Degeneration Terms

Reviewed by: HU Medical Review Board | Last reviewed: May 2023


Age-Related Eye Disease Study (AREDS)

The 2001 Age-Related Eye Disease Study (AREDS) found that a supplement formula can reduce the risk of developing advanced AMD. The researchers' recommended formula contained vitamins C and E, beta-carotene, copper (cupric oxide), and zinc.4

Age-Related Eye Disease Study 2 (AREDS2)

The same AREDS research group conducted a second study in 2006 called AREDS2. They looked at whether changes to the supplement formula had any effect on the progression of AMD. The new recommended formula contains vitamins C and E, copper (cupric oxide), lutein, zeaxanthin, and zinc.4

Age-Related macular degeneration (AMD)

A leading cause of vision loss in older people. Age-related macular degeneration (AMD) causes damage to the macula, which is the center of the retina. The macula helps you process what you see right in front of you (your central vision). When the macula is damaged, it results in black spots, blurriness, or blind spots in vision.1

Amsler grid

A test that helps alert you to changes in your vision or any progression of macular degeneration, particularly wet AMD. Similar to graph paper, this black-and-white grid can be used to spot changes in your condition. If you see any wavy or broken lines, dark spots, or missing areas, your macular degeneration may be progressing.3

Anti-VEGF therapy

Medicine that is injected into the eye to block the molecule VEGF, or vascular endothelial growth factor. VEGF is a protein that promotes the growth of abnormal blood vessels. Abnormally high levels of VEGF in the eyes can lead to wet AMD and severe vision loss.2


Bruch’s membrane

A membrane that separates the pigmented layer of the retina from the eye's choroid. Bruch's membrane regulates the exchange of nutrients, oxygen, fluid, and metabolic waste between the retina and your body's general circulation.5



A layer of tissue between the retina and the sclera. The choroid contains blood vessels that provide nourishment to the retina.6

Choroidal neovascularization

Growth of new, abnormal blood vessels from the choroid through Bruch’s membrane and into the sub-retinal pigment epithelium (RPE) space. This occurs with wet AMD and some cases of myopic macular degeneration (MMD).7


The clear, front part of the eye. The cornea bends light so it is focused on the retina.6


Dilated eye exam

A simple, painless exam that allows an eye doctor to check for many common eye problems. A doctor first puts drops into your eyes to dilate your pupils, allowing more light into your eyes. A dilated eye exam usually checks how clearly you see, your side (peripheral) vision, how light enters your eye, the pressure in your eyes, and the muscles around your eyeballs.8


A unit of measurement that represents the optical strength of a lens. Your diopter strength is the focusing strength of your glasses or contacts. A higher prescription has larger diopter numbers, and a milder prescription has smaller diopter numbers.9


Yellow deposits beneath the retina that are normal with aging. Drusen are made up of lipids and proteins. Having many drusen is often a sign of AMD.10


Condition that occurs when the macula slowly gets thinner with age. Dry AMD causes loss of central vision.11


Fluorescein angiography

An eye test that uses dye and a camera to check blood flow in the retina and choroid. It helps doctors diagnose and monitor eye diseases that can affect your retina.12


Geographic atrophy (GA)

An advanced form of AMD. Geographic atrophy (GA) affects the macula of the retina, causing blind spots in your central vision and permanent vision loss.13



The colored part of the eye. The iris also includes the pupil, which is a hole in the middle of the iris that gets smaller (constricts) and larger (dilates) to allow varying amounts of light into the eye.6



Part of the eye located right behind the pupil. The lens further focuses light that comes in through the cornea onto the retina. The lens also changes shape to help the eye focus on near or far objects. This is a reflex called accommodation.6

Low vision

A vision problem that makes it hard to do everyday activities. Low vision cannot be fixed with glasses, contacts, medicine, or surgery.14



Part of the retina that is responsible for central vision.6


Another word for nearsightedness. This means you can see objects that are nearby but may have trouble seeing objects farther away. People who have myopia have a larger or more oval-shaped eyeball. This makes light focus in front of the retina instead of on it.9

Myopic macular degeneration (MMD)

A type of macular degeneration that can occur in people with severe nearsightedness (myopia). MMD occurs when the retina slowly stretches over time. This process causes the eyeball to become more oval-shaped and the retina to become thinner. As that happens, the macula also stretches and becomes thinner. This leads to blurry, distorted central vision.9


Occupational therapist (OT)

A trained professional who uses functional activities to educate and help people maintain independence and safety at home or work. Occupational therapists (OTs) help people who have a variety of disabilities and injuries. OTs can help people with macular degeneration rearrange their house so it is easier to get around, learn how to use assistive devices, or modify their routine to take their low vision into account.15


A medical or osteopathic doctor (MD or DO) specializing in eye and vision care. Ophthalmologists have completed college, medical school, and specialized training, and they are licensed in both medicine and surgery. They can diagnose and treat eye disorders, perform surgery, and prescribe and fit glasses and contacts. Some also conduct research.16

Optic chiasm

Place in the brain where the 2 optic nerves come together.6

Optic nerve

A structure that connects each eye to the brain. The optic nerve also sends the pictures the eye sees to the brain for processing.6

Optical coherence tomography (OCT)

A noninvasive test that uses light waves to take pictures of your retina. Optical coherence tomography (OCT) pictures allow your eye doctor to map and measure the layers in your retina. The results help doctors diagnose and treat eye conditions like AMD and glaucoma.17


Technicians who have gone through training to properly fit glasses frames and lenses, contact lenses, and other devices to correct eyesight. They do not diagnose or treat eye disease. They also do not perform eye exams or write prescriptions for corrective vision devices.16


Healthcare professionals who specialize in primary vision care. Optometrists provide vision testing and eye exams, prescriptions for glasses and corrective lenses, and prescriptions for some medicines for certain eye diseases. They complete college followed by 4 years of optometry school to earn a doctor of optometry degree (OD).16



Specialized light-sensing cells that include rods and cones. Rods perceive black and white, and they are mostly used in night vision. Cones perceive color and are used in central vision.6



A thin, see-through structure covering the inner wall of the eye. The retina contains 10 layers of specialized cells, including rods and cones. When you look at something, the images are first projected onto the retina before traveling through your optic nerve to your brain.6

Retinal pigment epithelium (RPE)

A layer of cells deep in the retina. The retinal pigment epithelium (RPE) helps photoreceptor cells in the retina work by processing vitamin A products, absorbing light, and transporting nutrients.6

Risk factor

Something that increases a person's chance of developing a disease or other health issue.18


Stargardt disease

A genetic eye disorder that causes vision loss in children and young adults. In people with Stargardt disease, photoreceptor cells die off, causing central vision loss. The condition is sometimes called juvenile or early-onset macular degeneration.19



Part of an eye exam where eye pressure is measured. This is helpful in screening people for glaucoma.20


Visual acuity

Clarity or sharpness of vision. Ideal visual acuity is generally described as 20/20 vision. This means you can see clearly and easily at 20 feet what should typically be seen at that distance.21

Visual cortex

The area of the brain that receives visual information from the retina. The visual cortex helps process information about images and then sends the information to other parts of the brain. It is located in the back of the head.6

Visual field test

A test that measures how much vision you have in either eye and how much vision loss you may have. A visual field test is also used to check how your vision may be affected by eyelid issues. Eye doctors use several types of visual field tests. Regular tests are key for people who are at risk for vision loss from eye disease or other problems.22



A condition that occurs when abnormal blood vessels grow beneath the retina. These blood vessels are prone to swelling and leaking, which can damage the macula. Wet AMD is also called advanced neovascular AMD.1

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