Age-Related Macular Degeneration

Age-Related Macular Degeneration

Age-Related Macular Degeneration (AMD): Causes, Symptoms, and Treatment

1. What is Age-Related Macular Degeneration (AMD)?

Age-Related Macular Degeneration (AMD): An Overview

Age-Related Macular Degeneration (AMD) is the leading cause of irreversible vision loss in people over the age of 50 in high-income countries like the UK, and it is a major global health concern [1.2, 3.1]. AMD damages the macula, the central part of the retina responsible for sharp, detailed central vision needed for activities such as reading, driving, and recognizing faces [1.1, 3.2].

🔑 Key Message: Early detection is crucial, as treatment is more effective before significant damage occurs

Prevalence and Epidemiology

Global: In 2025, an estimated 200 million people worldwide are living with some form of AMD, a number projected to increase to 288 million cases by 2040 due to increasing life expectancy and population aging [1.2]. The risk of advanced AMD significantly increases with age:

• Ages 50–59: ≈2% risk of advanced AMD [1.2].
• Ages 75+: Risk climbs to as high as 30% [1.2]. AMD accounts for approximately 8.7% of global blindness [1.2].

United Kingdom (UK): AMD is the biggest cause of sight loss in the UK, affecting over 700,000 people [1.1, 1.3, 3.2].

• At age 60, about one in every 200 people has AMD [1.1, 1.3].
• By the age of 90, it affects one in five people [1.1, 1.3, 3.2]. Clinical data from NHS-funded treatment in 2021/22 showed that most people starting treatment were over 80 years old, and 60% were women [1.1].

India: The prevalence of AMD in India is generally reported to be lower than in Western nations, but it is a growing concern due to the expanding elderly demographic [2.1, 2.2].

• Overall prevalence in people above 40 years ranges from 1.2% to 4.7% [2.4].
• Prevalence in Western India has been reported as low as 1.4%, while in South India it was as high as 3.1% [2.4].
• A large-scale analysis in a hospital setting found that 1.68% of patients over 60 years of age were diagnosed with AMD [2.3].
• Around 7.6 million people in India are affected by AMD, with a projected annual increase [2.2].

Types of AMD

AMD progresses through two main stages:

1. Dry AMD: The most common form (about 80% of cases) [3.1]. It is characterized by the slow breakdown of light-sensitive cells in the macula. Late-stage dry AMD is also referred to as geographic atrophy (GA) [3.2]. Vision loss is usually gradual [3.1].

2. Wet (Neovascular) AMD: Less common, but it leads to more rapid and severe vision loss [3.1, 4.2]. It develops when abnormal, fragile blood vessels grow beneath the macula, a process called neovascularization. These vessels leak fluid and blood, causing scarring and rapid loss of central vision [1.1, 3.2, 4.3].

Risk Factors and Causes
The exact cause of AMD is unknown, but a number of factors are associated with its development. Age is the single greatest risk factor [3.3].

Modifiable Risk Factors:

• Smoking: The single biggest modifiable risk factor. Smokers are up to four times more likely to develop AMD than non-smokers. This risk can increase up to 20 times with a specific common gene for AMD [1.3, 3.2, 3.3, 3.4].
• Diet: A poor diet low in fruits and vegetables (antioxidants) and high in saturated fats, cholesterol, and high glycemic index foods may increase risk [1.3, 3.1, 3.2, 3.4].
• High Blood Pressure (Hypertension): People with high blood pressure are about one-and-a-half times more likely to have AMD [1.3, 3.1, 3.2, 3.4].
• Obesity: A Body Mass Index (BMI) greater than 30 increases the risk of developing the disease by 2.5 times [3.4].
• Inactivity and Prolonged Sun Exposure are also considered risk factors [3.4].

Non-Modifiable Risk Factors:

• Age: The primary risk factor, typically affecting people over 50 [3.1].
• Genetics/Family History: A family history of macular degeneration increases the chance of developing it [1.3, 3.2, 3.3, 3.4].
• Gender: Women are more frequently diagnosed, likely because they generally live longer than men [1.3, 3.2, 3.4].
• Race: Caucasians are more likely to develop AMD than other races [3.4].

Treatment and Management

Anti-VEGF Therapy for Wet AMD

The first-line treatment for wet AMD is an injection of Anti-Vascular Endothelial Growth Factor (Anti-VEGF) drugs directly into the eye (intravitreal injection) [4.1, 4.2, 4.3].

Mechanism of Action: In wet AMD, the body produces too much Vascular Endothelial Growth Factor (VEGF), a protein that stimulates the growth of new, unhealthy, and leaky blood vessels (neovascularization) [4.2, 4.3]. Anti-VEGF drugs work by blocking (inhibiting) this protein, which stops the growth of the abnormal blood vessels and reduces fluid leakage [4.1, 4.3].

Current Anti-VEGF Agents (Licensed and Off-Label) [4.1, 4.2, 4.3]:

• Ranibizumab (Lucentis): One of the first licensed anti-VEGF treatments [4.2].
• Aflibercept (Eylea): Longer-lasting than ranibizumab, with a high-dose (8mg) formulation allowing for longer intervals between injections [4.2, 4.3].
• Brolucizumab (Beovu): A longer-acting treatment, allowing for extended dosing intervals [4.2, 4.3].
• Faricimab (Vabysmo): The most recently approved, it is a dual-action drug that targets both VEGF and Angiopoietin-2 (Ang-2), further inhibiting abnormal blood vessel growth [4.2, 4.3].
• Bevacizumab (Avastin): An anti-VEGF drug developed for cancer, often prescribed off-label for wet AMD due to its safety and effectiveness [4.1, 4.2, 4.3].

AREDS2 Supplementation for Dry AMD

For patients with intermediate AMD or advanced AMD in one eye, the Age-Related Eye Disease Study 2 (AREDS2) formulation of supplements may reduce the risk of progression to advanced AMD by about 25% [5.1, 5.2, 5.3].

AREDS2 Recommended Daily Formula [5.1, 5.3]:

• Vitamin C: 500 mg
• Vitamin E: 400 IU
• Zinc (as zinc oxide): 80 mg
• Copper (as cupric oxide): 2 mg
• Lutein: 10 mg
• Zeaxanthin: 2 mg

The AREDS2 formulation notably replaced beta-carotene from the original AREDS formula with Lutein and Zeaxanthin due to the potential link between beta-carotene and increased risk of lung cancer in smokers [5.1].

Living Well with AMD

Adapting your lifestyle can significantly support your eye health and help you maintain independence.

1. STOP SMOKING: This is the single most important step you can take.
2. DIET: Eat foods rich in antioxidants, such as leafy green vegetables (spinach, kale), bright fruits, and oily fish.
3. SUN PROTECTION: Wear sunglasses that block UV rays to protect the retina from further damage.
4. ROUTINE CHECK-UPS: Stick to the monitoring schedule set by your specialist.
5. SUPPORTIVE CARE: Use assistive devices like magnifying glasses, large-print books, and screen readers to help maintain your daily activities. Ask your clinic about low-vision services available in your area (NHS in the UK, or local vision centres in India).

Bibliography

1. National Ophthalmology Database Audit. Second Annual Report of the Age-related Macular Degeneration (AMD) Audit Patient Summary 2024. 2024.
2. Contact Lenses. Macular Degeneration Statistics Worldwide in 2025.
3. Macular Society. Age-related macular degeneration.
4. Macular Society. What is macular degeneration? Causes, symptoms and treatment options.
5. Johns Hopkins Medicine. Age-Related Macular Degeneration (AMD).
6. Macular Disease Foundation Australia. About Age-Related Macular Degeneration.
7. BrightFocus Foundation. Macular Degeneration: Prevention & Risk Factors.
8. NIH NCBI Bookshelf. Anti–Vascular Endothelial Growth Factor Drugs for Age-Related Macular Degeneration.
9. Macular Society. Macular disease treatments.
10. Sapphire Eye Care. Wet AMD Treatment – Anti-VEGF injections.
11. BrightFocus Foundation. Vitamins for Age-Related Macular Degeneration: Do You Have the Correct Formula?.
12. Optometrists.org. Treating Macular Degeneration with AREDS: FAQs.
13. Macular Disease Foundation Australia. AREDS2 Supplements for Age-Related Macular Degeneration (AMD).
14. Current Research in Nutrition and Food Science Journal. Age-Related Macular Degeneration Risks Linked with Indian Dietary Fat Consumption Patterns. 2022.
15. ResearchGate. Prevalence of age-related macular degeneration and associated factors in Indian cohort in a tertiary care setting. 2023.
16. The New Indian Express. Prevalence of macular degeneration at 4.7% in people above 40 years in India. 2024.
17. Market Research Future. India Dry Age Related Macular Degeneration (AMD) Market Size, Growth Outlook 2035.