Macular Degeneration: Types, Symptoms, Diagnosis, and Treatment

Macular degeneration is a common but painless eye condition that results from the deterioration of the macula, or the central part of the retina. The macula, a light-sensitive layer of tissue at the back of the eye, is responsible for central or straight-ahead vision, which provides the ability to see fine detail in your direct line of sight.

As the macula deteriorates, it loses its ability to effectively convert light into light signals, thus making the center of your field vision appear blurry, distorted, or black.

Many contributing factors cause macular degeneration, including genetic abnormalities that can cause a form of macular degeneration known as Stargardt disease, which is common in children and teens.

The risk of developing the condition increases significantly with age, which is why it is also commonly known as age-related macular degeneration (AMD or ARMD) in general.

Macular degeneration is progressive, meaning it gets worse over time. But it does not cause total blindness because it does not affect peripheral vision.

AMD is the leading cause of vision problems in people aged 50 and older and affects more than 11 million people in the United States.

Types of Macular Degeneration

Experts classify macular degeneration into three types:

• Dry age-related macular degeneration: The more common type of AMD but is slow in its progression.
• Wet age-related macular degeneration: Less common than the dry form but more aggressive in its progression.
• Stargardt disease: A rare form of macular degeneration. According to the American Macular Degeneration Foundation, 1 in 20,000 cases of macular degeneration involves a child or a teenager, with the main cause being Stargardt disease.

Dry Age-Related Macular Degeneration

According to data pulled from the CDC, National Eye Institute, and Cleveland Clinic, between 80 and 90 percent of people who suffer from macular degeneration have the dry form. The National Eye Institute notes that this type of AMD is most common in people older than 60.

Also known as non-exudative or atrophic AMD, this form of AMD develops when tiny yellow proteins deposits, called drusen, form under the macula. The accumulation of deposits dries and thins the light-sensitive cells in the macula, causing a blurred spot in the center of your vision.

Over time, this blurred spot may gradually get bigger and darker, although most people might not lose central vision completely. Doctors often use terms like early, intermediate and late to describe the progression. In some rare cases, the dry form of AMD leads to wet AMD.

It is also important to note that drusen alone do not usually cause vision loss.

Wet Age-Related Macular Degeneration

Also known as exudative AMD, wet AMD is a more threatening form of AMD that accounts for between 10 to 20 percent of all AMD cases, according to the CDC and Cleveland Clinic. This form of AMD occurs when abnormal blood vessels occur under the retina and macula then leak blood and fluid – a condition known as choroidal neovascularization, or CNV.

The build-up of fluid causes a bulge to form in the macula that results in patients having distorted vision and seeing dark spots in the center of their vision. This form of AMD is more severe and can rapidly lead to a total loss of central vision when the leaking blood vessels eventually for a scar.

Stargardt Disease

Stargardt disease most often develops in children, teens and young adults because of a faulty gene (the ABCA4 gene) from both parents.

The hallmark of the condition is blurry vision, distorted vision or dark spots. Some people also have difficulty seeing or distinguishing colors.

Peripheral vision, or side vision, typically is not affected by Stargardt disease, even if central vision continues to deteriorate.

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Symptoms of Macular Degeneration

The signs and symptoms of AMD might not be apparent in early stages of the disease or if the condition affects both eyes simultaneously, making eye checkups and early detection important.

 Signs and symptoms of dry macular degeneration may include:

• A reduction in central vision in one or both eyes
• Increased blurriness of printed words
• Distortion of straight lines in the field of vision
• The need for brighter lighting when reading or doing close-up work
• Difficulty recognizing faces
• Increased difficulty adapting to low lighting
• Decreased brightness or intensity of bright colors

Signs and symptoms of wet macular degeneration may include:

• Hazy vision
• A blurry spot in your field of vision
• A well-defined blind spot/dark spot in the center of your field of vision due to blood vessels bleeding or leaking fluid
• Rapidly worsening symptoms

The symptoms associated with wet AMD often manifest when the condition is already severe. In some cases, wet AMD can even cause sudden loss of vision.

Causes of Macular Degeneration

The exact cause of all forms of macular degeneration is still unknown. However, the disease has been linked to both genetic and environmental factors. In general, people with a family history of the condition are at a higher risk of developing the condition.

Risk Factors of Macular Degeneration

The risk factors that can influence whether someone develops macular degeneration include:

• Aging
• Genetics (a family history of the disease)
• Sex (women are more prone to developing macular degeneration)
• Race (people with lighter skin tones are disproportionately affected by macular degeneration)
• Obesity and inactivity
• Smoking
• Cardiovascular disease
• High blood pressure
• High cholesterol

The American Academy of Ophthalmology notes that the findings on AMD risk factors are contradictory depending on the study. Although no one overriding factor predisposes people to macular degeneration, the academy also notes that the only risk factors consistently associated with AMD across the studies are aging and smoking.

Articles published in the British Journal of Ophthalmology and the International Journal of Ophthalmology also hold this view, but more research is needed.

How Is Macular Degeneration Diagnosed?

The key to managing macular degeneration is early detection. Among the tests to take at home or in an eye doctor’s office are:

• Basic eye examination
• Amsler grid
• Fluorescein Angiography
• Optical Coherence Tomography (OCT)

• Genetic testing

Basic Eye Examination

Doctors can spot the onset of AMD with a routine eye exam during a eye checkup. One of the earliest signs is the presence of drusen under your retina or pigment clumping. After dilating your pupils with eye drops, your doctor will also check for damage caused by drusen or an accumulation of fluids.

Amsler Grid

You can conduct this test at home, but your doctor can also give you one. It checks for defects in the center of your vision by looking at a pattern of straight lines that resemble a checkerboard – the Amsler grid.

If you notice that some of the straight lines appear wavy, darker, blurry, or are missing, it might be a sign of wet macular degeneration.

If you are doing this at home, follow these steps:

• Download an Amsler grid: here is a sample provided by The American Academy of Ophthalmology
• Wear your glasses or contacts as normal
• Hold the grid about 12 to 15 inches away from your face
• Cover one eye
• Look directly at the center dot with your open eye and focus on it
• While focusing on the center dot, observe if in your side vision all lines look straight and clear
• Repeat these steps with the other eye

If you notice that some of the straight lines appear wavy, darker, blurry, or are missing, contact your doctor immediately.

Your doctor will also use this test to monitor progress during treatment.

Fluorescein Angiography

Also referred to as indocyanine green angiography, doctors will inject colored dye into a vein on your arm. They will then use a special camera to take pictures as the dye travels to the blood vessels in your eye, highlighting them. If there are abnormal blood vessels or vessels bleeding or leaking fluid in your macula, the photos will show their exact location and type.

Optical Coherence Tomography (OCT)

This non-invasive test takes detailed cross-sectional images of your retina to help the doctor spot areas of swelling, thinning, and thickening. It is also used to track progress during treatment.

Genetic Testing

Doctors use genetic testing to identify young people at risk of Stargardt disease. Both parents must be carriers of a defective gene to pass the condition to one of their children.

Treatment Options for Macular Degeneration

Although there is no definitive cure for age-related macular degeneration, several different approaches may be used to manage the condition and slow its progression depending on the form of macular degeneration you have.

For Stargardt disease, scientists hope that a gene therapy approach in the future may be helpful in replacing the defective genes that cause the condition.

Your doctor will determine the specific treatment for AMD based on:

• Your age, overall health and medical history
• Your tolerance for specific procedures, medications and low-vision therapies
• Extent and nature of the disease
• Expectations for the course of the disease
• Your opinion or preference

Treatment Options for Dry Age-Related Macular Degeneration

No treatments exist for dry macular degeneration, although there are many clinical trials in progress. Dry AMD is slowly progressive and often affects one eye more than the other. People with this condition can therefore live relatively normal and productive lives.

Unfortunately, once dry AMD reaches the advanced stage, nothing can prevent further loss of vision. To slow this progress, patients can make lifestyle changes and take a combination of vitamins and nutritional supplements, AREDS and AREDS2 formulas (like Preservision AREDS2).

Because dry AMD does not cause total blindness, vision rehabilitation and low vision devices such as a telescopic lens implant can be used to develop new ways to perform daily living activities, build visual skills and adjust to living with AMD.

Treatment Options for Wet Age-Related Macular Degeneration

Doctors have various treatment options available to help slow the progression of wet AMD, preserve existing vision and, if started early enough, recover some lost vision. Medication, therapies and even surgery are possible.

Medications for Wet Age-Related Macular Degeneration

This is the primary treatment option for wet AMD. It involves the injection of medications called anti-VEGF agents, which stands for vascular endothelial growth factor. These medications help stop the growth of abnormal blood vessels by blocking the effects of growth signals sent by the body to generate new blood vessels. They are able to effectively stabilize vision in many patients and even improve the level of visual acuity in some patients. The medications used to treat wet age-related macular degeneration include;

• Bevacizumab (Avastin)
• Ranibizumab (Lucentis)
• Aflibercept (Eylea)
• Brolucizumab (Beovu)

Anti-VEGF medications are administered by injecting them directly into the affected eye. The procedure is done with a very fine needle under the cover of anesthetic eye drops so patients can be comfortable. This treatment is administered regularly over several months under the guidance of your doctor. Although there are possible risks associated with this treatment, if effective, this treatment has been shown to restore vision in some people and prevent blindness in up to 90% of those who receive it.

Therapies and Surgical Procedures for Wet Age-Related Macular Degeneration

Medical professionals have three strong treatment options for wet AMD. They are:

• Photodynamic Laser Therapy. The doctor injects a light-sensitive drug, verteporfin (Visudyne), into the patient’s bloodstream, where it is absorbed by the abnormal blood vessels. The doctor then shines a laser into your eye that triggers the medication to damage the abnormal blood vessels.
• Laser Photocoagulation. This is an older procedure in which a laser is used to seal off abnormal blood vessels to give them a chance to regrow, as detailed by Johns Hopkins Medicine. However, as with laser photocoagulation, the treatment may also destroy healthy surrounding tissue. For this reason,only patients with new vessels away from the exact center of vision (fovea) can receive this treatment.
• Low Vision Rehabilitation. Since wet AMD does not affect your peripheral (side) vision, it does not cause total blindness. For this reason, many people can significantly benefit from having the help of a healthcare professional to guide them find ways to adapt to their vision using special eyewear and other assistive devices. A low vision rehabilitation therapist, eye doctor, occupational therapist, or other healthcare professional with specific training in this area can be of great assistance.

Lifestyle Changes, Home Remedies & Supplements that Help with Macular Degeneration

Below are some of the steps you can take to slow vision loss upon receiving a diagnosis of macular degeneration.

• Don’t smoke. And if you smoke, seek help to quit. Smokers are more likely to develop advanced macular degeneration.
• Adopt a Healthy Diet. Choose a diet rich in antioxidant vitamins which promote eye health. Vegetables such as spinach, kale, squash, and broccoli have a high level of antioxidants, including zeaxanthin and lutein, which benefit people with macular degeneration. Food with high levels of zinc including high protein foods like beef, lamb, and pork as well as non-meat sources like yoghurt, milk, cheese, whole wheat bread, and whole-grain cereals are beneficial to people with macular degeneration. Healthy saturated fats such as olive oil as also a great choice. Research published on the Association for Research in Vision and Ophthalmology shows that a diet rich in omega-3 fatty acids such as those found in tuna, salmon, and walnuts can lower the risk of advanced AMD.
• Manage Your Health. If you have other medical conditions such as high blood pressure or cardiovascular disease, follow your doctor’s guidance to keep the condition under control.
• Maintain a Healthy Weight and Exercise Regularly. Reduce your calorie intake and increase the amount of exercise.
• Have Routine Eye Check-ups. Consult with your doctor on a good schedule for follow-ups ensuring that you perform self-assessments in-between visits with an Amsler grid.

Vitamin Supplements

If you have intermediate or advanced AMD, taking a high dose of antioxidant vitamins and minerals may help lower the risk of vision loss. Research sponsored by the National Eye Institute, AREDS, and AREDS2, shows great benefit in taking a formulation that includes the following:

• 500 milligrams (mg) of vitamin C
• 80 mg of zinc (as zinc oxide)
• 2 mg of zeaxanthin
• 400 international units (IU) of vitamin E
• 2 mg of copper (as cupric oxide)
• 10 mg of lutein

While taking supplements may be helpful, there are also side effects so be sure to consult with your doctor about which supplements are right for you.

Prevention of Macular Degeneration

You can reduce your risk of developing macular degeneration with the following tips:

• Quit smoking
• Regular exercise
• Maintain a healthy weight
• Avoid ultraviolet and blue light which the AMDF shows are harmful to the retina
• Wear proper eye protection when outdoors to reduce your risk for AMD and maintain eye health
• Choose a diet healthy in antioxidants and nutrients

The AREDS/AREDS2 diet may help slow the progression of AMD, delay or even minimize vision loss. Additionally, as published in the journal Ophthalmology, eating a Mediterranean Diet emphasizing whole grains, vegetables, fruit, fish, olive oil, some dairy, and red wine is linked with a lower risk of developing wet AMD.

Outlook for People with Macular Degeneration

While macular degeneration might seem like an intimidating and scary condition to contend with, people rarely lose all their vision from age-related macular degeneration. With dry AMD, vision loss happens gradually and can take a long time to occur so you can keep most of your vision. During this time, most people will still be able to do many normal daily activities. Wet AMD is a leading cause of permanent vision loss and if it affects both eyes, it can significantly lower your quality of life and you might be considered legally blind.

Early detection with regular dilated eye exams can help slow the disease progression and reduce the risk of vision loss.

Make sure you follow through on your routine eye check-ups and if you experience any changes in vision between visits, contact your doctor right away.

Frequently Asked Questions

What are the early signs of macular degenerations?

The Macular Disease Foundation Australia notes that most people cannot detect any signs that they have macular degeneration during the early and intermediate stages of the condition. That is because the earliest sign of AMD is drusen in the macula which can only be detected by an eye doctor during a dilated eye examination.

However, as the disease progresses, the earliest signs you will get are blurred or distorted vision, dark or hazy patches in the center of your vision, and difficulty reading. Since the condition is painless, most people presume most of the early signs as tiredness or sleepiness thus making routine eye exams crucial in the early detection of macular degeneration.

What is the main cause of macular degeneration?

The exact cause of macular degeneration remains unknown. However, there is strong evidence that heredity and environmental factors play a key role in developing macular degeneration.

Can you fix macular degeneration?

Unfortunately, there is no definitive cure yet for macular degeneration. However, there are various treatment options that can slow the progression of the disease and keep you from having severe loss of vision.

References

1. Eye Anatomy: Parts of the Eye and How We See. (March 2021). The American Academy of Ophthalmology.

2. What Is Stargardt Disease? (May 2021). The American Academy of Ophthalmology.

3. Stargardt Disease – Juvenile Macular Degeneration. (May 2021). The American Academy of Ophthalmology.

4. Age-Related Macular Degeneration (AMD) Data and Statistics. (July 2019). The National Eye Institute.

5. Epidemiology of age-related macular degeneration (AMD): associations with cardiovascular disease phenotypes and lipid factors. (December 2016). Eye and Vision.

6. Stargardt Disease Defined. (March 2021). American Macular Degeneration Foundation

7. Age-Related Macular Degeneration. (August 2021). Centers for Disease Control and Prevention.

8. Age-Related Macular Degeneration. (December 2020). Cleveland Clinic.

9. Age-Related Macular Degeneration. (January 2021). American Academy of Ophthalmology.

10. Smoking and Age-Related Macular Degeneration: Review and Update. (December 2013). British Journal of Ophthalmology.

11. Smoking and age-related macular degeneration: the number of pack-years of cigarette smoking is a major determinant of risk for both geographic atrophy and choroidal neovascularisation. (December 2005). International Journal of Ophthalmology.

12. Have AMD? Save Your Sight with an Amsler Grid. (May 2020). The American Academy of Ophthalmology.

13. Age-Related Macular Degeneration (AMD). (June 2015). Johns Hopkins Medicine.

14. Age-Related Eye Disease Studies (AREDS/AREDS2). (April 2020). National Eye Institute.

15. Living with AMD-Age-related macular degeneration (AMD). (April 2021). National Health Services.

16. Photodynamic Therapy for Age-Related Macular Degeneration. (June 2015). Johns Hopkins Medicine.

17. Circulating Omega-3 Fatty Acids and Neovascular Age-Related Macular Degeneration. (March 2014) Association for Research in Vision and Ophthalmology.

18. Risk Factors for Macular Degeneration. (May 2020). American Macular Degeneration Foundation.

19. Mediterranean Diet and Incidence of Advanced Age-Related Macular Degeneration. (August 2018). Ophthalmology.

20. Symptoms of age-related macular degeneration. (June 2019). Macular Disease Foundation Australia.