What is Macular Degeneration, Its Causes, Treatments, and Prevention Methods?

Age-related macular degeneration (AMD) is a medical condition that affects the retina of the eye as people age. It is commonly known as age-related macular degeneration. There are different types of AMD, and it can cause central vision loss. In this article, we will discuss in detail what macular degeneration is, its symptoms, causes, treatment options, and prevention methods.

What is Macular Degeneration?

Age-related macular degeneration (AMD) is an eye disease that affects central vision. It typically occurs in individuals aged 50 and older. AMD impacts the macula, the central part of the retina.

The retina is located at the back of the eye and controls central vision. People with AMD often experience central vision loss, making it difficult to see objects directly in front of them. However, peripheral vision, or the ability to see objects to the side, usually remains unaffected. AMD can affect one or both eyes and can vary in severity.

What Causes Macular Degeneration?

The most common cause of macular degeneration is genetics, although it can also occur in individuals with no family history. It happens when the macula—located at the back of the eye—begins to deteriorate for unknown reasons. Age is considered a major contributing factor.

Other risk factors and causes include:

• Family history of AMD
• Obesity
• Smoking
• High blood pressure
• Diet high in saturated fats
• Diabetes
• Head injuries
• Infections
• Poor nutrition

Types of Macular Degeneration

There are two main types of AMD:

1. Dry AMD

This is the most common form, accounting for about 90% of cases. It develops when small yellow protein deposits called drusen accumulate under the macula, leading to its drying and thinning.
Vision loss in this type progresses slowly, and most people retain some central vision. In some cases, dry AMD can progress to wet AMD.

2. Wet AMD

This type occurs when abnormal blood vessels grow under the retina and macula. These vessels leak blood and fluid, causing swelling in the macula and dark spots in central vision.
Wet AMD represents about 10% of AMD cases but is more severe and can lead to rapid central vision loss.

Stages of Macular Degeneration

Dry AMD progresses through three stages:

• Early AMD: Changes in the macula occur, but vision remains unaffected.
• Intermediate AMD: Vision becomes blurry or wavy.
• Advanced AMD: Central vision is significantly impaired.

Wet AMD is already considered an advanced stage of the disease.

Symptoms of Macular Degeneration

The macula transmits visual signals from the optic nerve to the brain. When damaged, the brain can't accurately interpret the images seen by the eye. In early stages, symptoms may not appear. As the condition progresses, the following symptoms may develop:

• Difficulty seeing in low light
• Blurred or distorted vision
• Trouble recognizing colors
• General visual distortion
• Straight lines appearing wavy
• Dark or empty spots in the central field of vision

How is Macular Degeneration Diagnosed?

Diagnosis begins with a comprehensive eye exam. Other diagnostic tools may include:

• Retinal Exam: The doctor examines the retina after dilating the pupils with medication.
• Amsler Grid Test: The patient looks at a grid resembling a checkerboard. Wavy or missing lines may indicate AMD.
• Fluorescein Angiography or OCT (Optical Coherence Tomography): These imaging tests detect fluid or blood under the retina. A dye may be injected into a vein in the arm, and images are taken as it flows through the retinal vessels. Abnormal vessels and leaks can be identified.

How is Macular Degeneration Treated?

There is currently no definitive cure for AMD, but early treatment can slow its progression and lessen its impact. Depending on the type of AMD, treatments may include nutritional supplements, medications, photodynamic therapy, or laser treatment.

Supplements for Dry AMD

Studies have shown that specific vitamins and minerals can slow the progression of dry AMD and support eye health in older adults. Key supplements include:

• Vitamin C
• Vitamin E
• Lutein
• Zinc
• Copper
   

Medications for Wet AMD

Several drugs are used to treat wet AMD by targeting vascular endothelial growth factor (VEGF), which stimulates the formation of abnormal blood vessels. These are typically administered via injections into the eye:

• Aflibercept
• Ranibizumab
• Bevacizumab
• Faricimab-svoa
• Brolucizumab
   

Photodynamic Therapy for Wet AMD

This treatment combines a light-sensitive injectable drug with a laser to destroy abnormal blood vessels in the eye.

Laser Photocoagulation

This surgical laser treatment seals off leaky blood vessels. However, it’s now rarely used due to the effectiveness of anti-VEGF injections.

Complications of Macular Degeneration

Loss of central vision can make certain tasks difficult, including:

• Reading
• Recognizing faces
• Driving
• Performing household tasks
   

In severe cases, AMD can lead to legal blindness. Lifestyle changes due to vision loss can cause depression or anxiety. Some patients also experience Charles Bonnet syndrome, which causes visual hallucinations.

How Can You Prevent Macular Degeneration?

To reduce the risk of developing AMD, consider the following preventive measures:

• Quit smoking
• Maintain a healthy weight
• Stay physically active
• Control blood pressure and cholesterol
• Follow a Mediterranean-style diet

Frequently Asked Questions

Can macular degeneration be cured?
There is no permanent cure for AMD, but effective treatments exist that can stop or slow its progression.

Is macular degeneration a serious condition?
Wet AMD can be very serious, potentially causing severe vision loss and even blindness in the affected eye.