What is AMD?

Age-Related Macular Degeneration (AMD) is a progressive eye disease that affects the macula, the small central area of the retina responsible for sharp, detailed vision. It is the leading cause of severe, irreversible vision loss among adults over 35 in developed countries.

AMD does not cause total blindness, but it can significantly impair central vision—the vision you rely on for reading, driving, recognizing faces, and performing everyday tasks. Peripheral (side) vision typically remains intact.

Approximately 20 million Americans are currently living with some form of AMD, and that number is expected to grow significantly by 2050 as the population ages.

Watch: Introduction to AMD

Introduction to Age-Related Macular Degeneration (AMD) — M. Cristina Kenney, MD, PhD

How Your Eye Works

To understand AMD, it helps to know how the eye processes light into vision:

The retina is a thin layer of light-sensitive tissue lining the back of the eye. It converts light into electrical signals that travel to the brain via the optic nerve.
The macula is a tiny, specialized area at the center of the retina. Despite being only about 5 millimeters across, it is responsible for all of your central, high-resolution vision.
The retinal pigment epithelium (RPE) is a layer of cells beneath the retina that nourishes and supports the photoreceptors. In AMD, this supportive layer begins to break down.

The macula contains the highest concentration of cone photoreceptors in the eye, giving you the ability to see fine detail and color. When the macula is damaged by AMD, these capabilities decline.

Types of AMD

There are two main forms of AMD, each with different characteristics and progression patterns:

Dry AMD (Atrophic)

Dry AMD accounts for approximately 80–90% of all AMD cases. It develops when small yellow deposits called drusen accumulate beneath the retina. Over time, the macula thins and breaks down.

Progresses gradually over years
May affect one or both eyes
Early stages often have no noticeable symptoms
Advanced dry AMD is called geographic atrophy

Wet AMD (Neovascular)

Wet AMD accounts for roughly 10–20% of cases but is responsible for about 90% of severe vision loss from AMD. Abnormal blood vessels grow beneath the retina (a process called choroidal neovascularization).

Can cause rapid and severe vision loss
Abnormal vessels leak blood and fluid
Always develops from pre-existing dry AMD
Treatable with anti-VEGF injections

Symptoms of AMD

AMD symptoms vary depending on the stage and type of the disease:

Early AMD

Usually no noticeable symptoms
May be detected only during a comprehensive eye exam
Small or medium-sized drusen present

Intermediate AMD

Mild blurriness in central vision
Difficulty seeing in low-light conditions
Need for brighter light when reading or doing close work
Colors may appear less vivid

Late AMD

Noticeable blurry or dark area in the center of vision
Straight lines appear wavy or distorted (metamorphopsia)
Difficulty recognizing faces
Rapid worsening of central vision (especially wet AMD)
Colors appear washed out or faded

Warning: If you suddenly notice that straight lines appear wavy or distorted, or you see a dark spot in your central vision, contact your eye doctor immediately. These may be signs of wet AMD, which requires urgent treatment.

The Amsler Grid

The Amsler grid is a simple visual tool used to monitor changes in central vision. It consists of a grid of straight lines with a dot at the center.

How to Use the Amsler Grid

Wear your reading glasses or contacts if you normally use them
Hold the grid at a comfortable reading distance (about 12–15 inches)
Cover one eye and focus on the center dot with the uncovered eye
Note whether any lines appear wavy, blurry, or missing
Repeat with the other eye

What to Look For

Lines that appear wavy, bent, or distorted
Dark or blank areas in the grid
Areas that look different from the last time you checked

Important: The Amsler grid is a monitoring tool, not a diagnostic test. It is not a replacement for regular comprehensive eye exams by an eye care professional. If you notice changes in your grid results, contact your doctor promptly.

How Doctors Check for AMD

Eye care professionals use several tests and technologies to detect and monitor AMD:

Dilated Eye Exam Your doctor places drops in your eyes to widen the pupils, allowing a detailed view of the retina and macula. This is the most common initial screening method for AMD.
Optical Coherence Tomography (OCT) A non-invasive imaging test that creates detailed cross-sectional images of the retina. OCT can detect fluid, drusen, and thinning of the retinal layers with high precision.
Fundus Photography High-resolution photographs of the retina that provide a permanent record for tracking disease progression over time.
Fluorescein Angiography A dye is injected into the arm and photographs are taken as it circulates through the blood vessels of the retina. This test identifies leaking blood vessels characteristic of wet AMD.

Questions to Ask Your Doctor

If you or a loved one has been diagnosed with AMD, consider asking your eye care provider these questions:

What type and stage of AMD do I have?
How quickly is my AMD likely to progress?
Are there treatments available for my stage of AMD?
Should I be taking AREDS 2 supplements?
How often should I have follow-up eye exams?
What symptoms should prompt me to contact you urgently?
Are there lifestyle changes I can make to slow progression?
Can you recommend low vision resources or rehabilitation services?

                Key Takeaways
                AMD is the leading cause of severe vision loss in adults over 35
There are two types: dry AMD (most common) and wet AMD (most severe)
Early AMD often has no symptoms—regular eye exams are essential
The Amsler grid can help monitor changes between appointments
Early detection gives you the best chance of preserving your vision
Wet AMD requires prompt treatment to prevent rapid vision loss
New diagnostic approaches, including blood-based risk assessment, are being developed

            

Trusted Resources

Learn more from these reputable organizations:

National Eye Institute (NEI) Comprehensive AMD information from the National Institutes of Health
American Academy of Ophthalmology (AAO) Expert eye health resources and AMD guidelines
American Macular Degeneration Foundation (AMDF) Patient education, support, and research updates
BrightFocus Foundation Funding research and providing public education on macular degeneration