What is Macular Degeneration?

Macular degeneration is a complex, progressive eye disease that causes deterioration of the retina and damages the macula, the small, oval-shaped area at the center of the retina responsible for color vision, fine detail, and straight-ahead vision. Peripheral vision is unaffected, but the loss of the central field of vision can make activities of daily life difficult if not impossible. While seldom resulting in total blindness, advanced AMD can cause life-changing loss of central vision. See an animation of central vision loss.

The most common type of macular degeneration is age-related macular degeneration (AMD), the leading cause of irreversible vision loss in adults over age 60 in the US and worldwide. According to the American Macular Degeneration Foundation, AMD currently affects nearly 20 million Americans.

According to the World Health Organization‘s (WHO) 2020 World Vision Report, approximately 196 million people worldwide have been diagnosed with Macular degeneration. It is incurable and lost vision cannot be restored, but AMD’s progression may be slowed, and treatments are available for the late stages of the disease.

What Causes Macular Degeneration?

The exact cause of AMD remains unknown, although factors that drive its development and progression are becoming better understood. It is commonly believed that AMD is roughly 50% due to genetic makeup and 50% due to environmental and lifestyle factors that can increase disease risk/progression (and can also be modified to reduce risk/progression).

People whose parents have/had AMD are at approximately twice the risk of getting AMD themselves, when compared to someone whose parents have not had AMD. Several influential genes that are most associated with AMD play a role in the complement system, which is part of the immune system that attacks invading bacteria. Genes involved in cholesterol metabolism, collagen production and cell signaling have also been associated with risk for AMD.

Environmental or lifestyle factors that are associated with the greatest risk for AMD include poor diet, smoking, and exposure to the damaging blue range of sunlight.

Not all macular degeneration progresses to a later stage that results in vision loss.  Knowing one’s family history with AMD, understanding the modifiable risk factors that contribute to its development and progression, and monitoring through regular eye exams can help reduce risk and impact.

Types of Macular Degeneration

There are two types of AMD: wet and dry. Eighty percent of people with AMD have the dry variety, caused by a buildup of plaque-like deposits called drusen, and a thinning of the macular tissue, leading to further atrophy and dead zones (called Geographic Atrophy). Less common, but more dramatic, wet macular degeneration is caused by faulty blood vessel growth and leakage into the macula.

All macular degeneration begins as the dry form and can progress to either late dry AMD or wet AMD, or both.

Dry AMD sometimes progresses without affecting central vision, while wet AMD always affects central vision.

Risk Factors for Age-Related Macular Degeneration

Age is the primary risk factor for AMD, and the risk of developing it increases with age. One in three people age 75+ are at risk of getting it, and those who have it in one eye are at increased risk of developing it in the other eye.

Other risk factors include:

• Family history of AMD
• Lifestyle: A diet high in saturated fats and sugary carbs, and low in antioxidants increases risk, as does physical inactivity, obesity, and unprotected exposure to direct sunlight
• Smoking doubles your chance of developing AMD
• Poor air quality
• Race: Caucasians are likelier than other ethnic groups to develop it

Is Macular Degeneration Hereditary?

As noted above, a family history of AMD increases your risk. Juvenile Macular degeneration, called Stargardt disease (or Stargardt macular dystrophy & degeneration), is hereditary and can affect young people and even infants. Like AMD, Stargardt causes loss of central vision, sensitivity to light, fading of color, and/or color blindness, but its cause (genetic) and treatment are different. Learn more about Stargardt disease.

Symptoms of Macular Degeneration and Disease Progression

 In general, AMD  progresses over years in three stages: 

• Early dry AMD may cause no physical or vision symptoms. AMD that is detectable by a dilated pupil exam and other imaging techniques may begin to develop as early as age 40+.
• Intermediate dry AMD causes no change in vision in some people, while others notice blurred vision, difficulty seeing in low light, and colors may appear faded may occur in one’s 50s.
• Late AMD often brings blurriness and/or wavy central field vision, increased difficulty seeing in low light, loss of contrast sensitivity, and faded colors. Another symptom of late AMD is a blank spot in the center field of vision caused by retinal cell loss (geographic atrophy). These symptoms are more common for those in their 60s, 70s, and beyond.

Signs of Macular Degeneration, Exam, and Diagnosis

Many people ask, is there is a test for Macular degeneration?The answer is yes, there are several!

The first sign of this eye disease is a loss of the ability to adapt from a bright environment to darker surroundings. This change, while detectable by dark adaptation testing, is so subtle that most people do not realize that it is a symptom of disease and do not get tested. 

Most frequently,  during a comprehensive eye exam with pupil dilation, the first indications of AMD are drusen — small amounts of cellular waste, yellow or white in color, that can be seen littering the surface of the retina. Most people over age 50 will have some drusen present. Some people experience no progression of the disease beyond this point. A high volume of drusen, however, can be an early indication of AMD, as can macular pigment change.

Screening Tools

Early detection in an eye exam before changes in vision occur offers the best chance of preserving useful vision. Most people, however, do not seek help until they experience symptoms of vision loss  If you have a family history of AMD or have one or more of the known risk factors, speak with your physician or eye doctor about how frequently you should have regular eye exams with dilation.

A comprehensive eye exam will include a visual acuity test (the letter chart) and the Amsler grid, which looks like graph paper and is used to detect wavy vision or gaps in vision.

Other diagnostic tests to detect the presence and progress of AMD include:

• FA: Fluorescein angiography—Dye is injected into the arm that travels to blood vessels in the eye and is captured by a special camera showing leaks or changes in the retina.
• ICGA: Indocyanine green angiography—Dye is injected into the arm to look deeper into the retina.
• OCT: Optical coherence tomography—This non-invasive imaging test that looks for abnormalities in the retina and monitors response to treatment.
• OCTA: Optical coherence tomography angiography—is non-invasive imaging that looks for blood vessel abnormalities in the retina

Macular Degeneration Treatment

There are several treatmentsfor AMD, depending on its stage and whether it is wet or dry. Treatment is focused on slowing disease progression.

Early stage dry AMD should be monitored with regular eye exams. Interventions  include maintaining an AMD-healthy diet, which has been shown to reduce the likelihood of transitioning to later stages of the disease. Regular physical activity and maintaining recommended body weight and blood pressure also reduce risk for disease progression.

For intermediate dry AMD in one or both eyes, in addition to maintaining the proper diet, special dietary supplements known as the AREDS or AREDS2 formula can slow progression. Learn more about supplements for AMD. A non-invasive treatment, known as photobiomodulation, that stimulates energy production in retinal cells and slows disease progression, was recently approved by the FDA.

For late dry AMD (geographic atrophy, or GA), two recently FDA-approved treatments  can slow the growth of areas of atrophy. Both of these — Pegcetacoplan and Avacincaptad Pegol — are Injections into the eye Recent studies show that the AREDS and AREDS2  supplements are also effective in late dry AMD.

Wet AMD can be treated with Anti-VEGF (anti-vascular endothelial growth factor) medication injections into the eye to inhibit the growth of abnormal blood vessels and leakage, and to prevent further vision loss. Photodynamic therapy (PDT) uses non-thermal lasers and medication to target and treat abnormal blood vessels in the eye and can also prevent progression.  Laser photocoagulation treatment is a minimally invasive procedure — or surgery – that can prevent further vision loss caused by wet AMD. As with any medical treatment or procedure, these come with both benefits and risks. Speak with your doctor about the best option for you. Learn more about treatments for wet AMD.

Treatment for wet AMD does not stop the progression of dry AMD. Although there is currently no treatment to halt late stage dry AMD, robust research into treatments continues.

Self-care for AMD at any stage, as well as for prevention, includes a maintaining a healthy diet, staying physically active, not smoking, monitoring your vision for any changes, and reporting any vision changes as soon as possible to an eye care specialist.

Vision Rehabilitation Therapy Delivers Solutions

In addition to treatment, vision rehabilitation can provide life-changing results:

• Independent Living Skills Training teach tailored strategies that help clients safely and confidently navigate life in their community.
• Orientation & Mobility Training (O&M) includes white cane training and dog guides.
• Assistive Technology features the latest and most effective magnifiers, screen readers, speech recognition software, and other aids.
• Low Vision Aids & Devices compensate for vision loss using magnifiers, special glasses, talking devices and appliances, and many more.

• Employment Services & Vocational Rehabilitation provide guidance and techniques to help overcome vision-related challenges on the job.
• Braille Training for reading and writing in this international tactile language is empowering and edifying.
• Support Groups & Counseling can be socially enriching and emotionally fortifying.

Learn more about Macular Degeneration and hear about success stories through this series of videos from the American Macular Degeneration Foundation.