Age-related macular degeneration (AMD): Risk factors, symptoms, and treatment

Age-related macular degeneration (AMD) is a prevalent eye condition characterised by alterations in central vision.

Here, Mr Sameer Trikha, renowned consultant ophthalmic surgeon, offers an expert insight into the key aspects of AMD, including its risk factors, symptoms, and effective management.

What is AMD?

AMD is a condition that affects the central part of the retina, known as the macula, which is the part of the retina that allows us to see fine detail for tasks such as reading. AMD occurs when the macula becomes damaged.

What are the types of AMD?

There are two main types of AMD:

• A dry form, known as dry macular degeneration
• A wet form, known as wet macular degeneration

What are the risk factors for AMD?

Several risk factors can increase the likelihood of developing AMD.

These risk factors include:

• Age: The primary risk factor for AMD is age. The condition is more common in individuals over the age of 50, and the risk increases with advancing age.
• Genetics: A family history of AMD can contribute to an individual's risk. If a close relative, such as a parent or sibling, has AMD the likelihood of developing the condition may be higher.
• Smoking: Smoking has been strongly associated with an increased risk of AMD. Individuals who smoke are more likely to develop both early and late stages of the disease.
• Race and ethnicity: AMD is more common in individuals who are Caucasians compared to other racial and ethnic groups. Additionally, studies suggest that individuals of European descent may have a higher risk.
• Gender: Women may be at a slightly higher risk than men for developing AMD, particularly the more advanced forms of the disease.
• Nutrition: Poor nutrition, particularly a diet low in antioxidants, vitamins and minerals, may be associated with an increased risk of AMD. Conversely, diets rich in fruits, vegetables, and fish may be protective.
• Cardiovascular disease: Conditions such as hypertension (high blood pressure), high cholesterol, and cardiovascular disease have been linked to an increased risk of AMD.
• Obesity: Being overweight or having obesity may contribute to the risk of AMD. Maintaining a healthy weight is important for overall eye health.
• Sunlight exposure: Prolonged exposure to sunlight, especially without protection, may be a risk factor for AMD. Wearing sunglasses that block harmful UV rays may help reduce this risk.
• Hormone replacement therapy (HRT): Some studies suggest that postmenopausal women who have undergone HRT may be at a higher risk for developing AMD.

It's important to note that having one or more of these risk factors doesn’t guarantee the development of AMD, and that individuals without these risk factors can still develop the condition. Regular eye exams and lifestyle modifications can play a role in reducing the risk and managing AMD.

What are the symptoms of AMD?

AMD often progresses slowly and may not cause noticeable symptoms in its early stages.

However, as the condition progresses, individuals may experience:

• Blurred or distorted vision: One of the most common symptoms of AMD is a gradual or sudden loss of central vision. This can lead to blurred or distorted vision, making it difficult to see fine details.
• Difficulty reading or performing close-up tasks: AMD can make it challenging to read or perform activities that require sharp central vision, such as recognising faces, reading, writing, or sewing.
• Dark or empty areas in central vision: In some cases, individuals who have AMD may notice dark or empty areas in the centre of their vision. This can create a "hole" or "blind spot" in their visual field.
• Straight lines appearing wavy: Straight lines may appear distorted or wavy, a phenomenon known as metamorphopsia. This distortion is often a characteristic sign of AMD.
• Difficulty recognising faces: As central vision deteriorates, recognising faces, especially in low-light conditions, may become challenging for individuals who have AMD.
• Decreased colour brightness or intensity: Some individuals who have AMD may experience a decrease in the intensity of colours, making them appear less vibrant.
• Difficulty adapting to low light: AMD can make it harder for individuals to adapt to changes in lighting conditions, particularly when moving from bright to dim environments.

AMD primarily affects central vision, leaving peripheral vision intact. In some cases, only one eye may be affected, while the other eye compensates for the loss of vision.

If you experience any of these symptoms or notice changes in your vision, it's crucial to seek prompt evaluation by an eye care professional. Early detection and management can help slow the progression of AMD and preserve vision to some extent.

What are the treatments for AMD?

Treatment options for AMD depend on the stage of the disease and whether it’s classified as "dry" or "wet" AMD. Dry AMD is more common and typically progresses slowly, while wet AMD involves the growth of abnormal blood vessels beneath the macula, leading to a faster progression of vision loss.

Dry AMD treatments

• Vitamin supplements: High-dose antioxidant vitamins and minerals, known as the AREDS (age-related eye disease study) formulation, have been shown to slow the progression of intermediate to advanced dry AMD. This supplement includes vitamins C and E, zinc, copper, and beta-carotene.
• Lifestyle modifications: Adopting a healthy lifestyle, including a nutritious diet rich in fruits and vegetables, maintaining a normal weight, regular exercise, and avoiding smoking may help reduce the risk of progression in dry AMD.
• Low vision aids: For individuals who have advanced dry AMD causing significant vision loss, low vision aids such as magnifiers, telescopic lenses, and adaptive technologies can help maximise remaining vision and improve quality of life.

Wet AMD treatments

• Anti-VEGF injections: Wet AMD is often treated with anti-vascular endothelial growth factor (VEGF) drugs, administered through injections into the eye. These medications, such as ranibizumab, aflibercept, and bevacizumab, help inhibit the growth of abnormal blood vessels and can improve or stabilise vision in many cases.
• Photodynamic therapy (PDT): PDT involves injecting a light-sensitive drug into the bloodstream, followed by shining a laser into the eye to activate the drug. This treatment is less commonly used than anti-VEGF injections and is typically reserved for specific cases.
• Laser therapy: Laser therapy, such as focal laser treatment, may be used in certain cases of wet AMD to target and seal leaking blood vessels. However, this approach is less common with the advent of anti-VEGF therapies.

It's important to note that while these treatments can be effective in stabilising or improving vision, they may not completely restore lost vision. The success of treatment often depends on factors such as the stage of AMD, the presence of other eye conditions, and how promptly the condition is diagnosed and treated.

Regular eye exams, especially for individuals over the age of 50 or for those with risk factors, are essential for monitoring eye health and detecting conditions like AMD in their early stages.

To schedule an appointment with Mr Sameer Trikha, head on over to his Top Doctors profile today.