Age-Related Macular Degeneration AMD

Age-related macular degeneration (AMD) is a common eye condition that affects the central part of the retina called the macula, which is responsible for sharp, central vision needed for activities such as reading, driving, and recognizing faces. AMD primarily affects older adults and is a leading cause of vision loss in people aged 50 and older.

Types of AMD

There are two main types of AMD:

Dry AMD (Atrophic)

• Prevalence: Most common form, accounting for about 80-90% of cases.
• Characteristics: Gradual breakdown of the macula, leading to a slow progression of vision loss.
• Drusen: Yellow deposits under the retina, which are an early sign of dry AMD.
• Geographic Atrophy: Advanced form of dry AMD where areas of the retina become thinner and lose function.

Wet AMD (Neovascular or Exudative)

• Prevalence: Less common but more severe than dry AMD.
• Characteristics: Growth of abnormal blood vessels under the retina and macula, which can leak blood and fluid.
• Rapid Vision Loss: Can lead to rapid and severe vision loss if untreated.
• Symptoms: Distortion of central vision, such as straight lines appearing wavy, and dark spots in the central vision.

Risk Factors

• Age: Risk increases with age, particularly in people over 50.
• Genetics: Family history of AMD increases the risk.
• Race: More common in Caucasians.
• Smoking: Increases the risk of developing AMD.
• Diet: Poor diet lacking in fruits and vegetables.
• Obesity: Associated with a higher risk of developing AMD.
• Cardiovascular Disease: Conditions such as hypertension and high cholesterol can increase the risk.

Symptoms

• Blurry Vision: Especially in the center of the visual field.
• Dark or Empty Areas: Appearance of dark or empty areas in the center of vision.
• Distorted Vision: Straight lines may appear bent or wavy.
• Difficulty with Fine Details: Trouble recognizing faces or reading small print.

Diagnosis

• Comprehensive Eye Exam: Includes a visual acuity test, dilated eye exam, and retinal imaging.
• Amsler Grid: A grid used to detect changes in central vision.
• Optical Coherence Tomography (OCT): Imaging test that provides detailed images of the retina.
• Fluorescein Angiography: Dye is injected into the bloodstream to highlight blood vessels in the retina.

Treatment

Dry AMD

• Lifestyle Changes: Diet rich in leafy greens, fish, and nuts; quitting smoking; managing cardiovascular health.
• AREDS Supplements: High-dose vitamins and minerals based on the Age-Related Eye Disease Study (AREDS) formula may slow progression.
• Monitoring: Regular eye exams to monitor the condition.

Wet AMD

• Anti-VEGF Injections: Medications such as ranibizumab (Lucentis), aflibercept (Eylea), and bevacizumab (Avastin) are injected into the eye to inhibit the growth of abnormal blood vessels.
• Photodynamic Therapy (PDT): Uses a light-activated drug to close abnormal blood vessels.
• Laser Therapy: High-energy lasers are used to destroy abnormal blood vessels.

Prevention and Management

• Regular Eye Exams: Early detection and monitoring.
• Healthy Lifestyle: Balanced diet, regular exercise, avoiding smoking, and protecting eyes from UV light.
• Supplements: As recommended by eye care professionals based on the AREDS studies.

Research and Future Directions

• Stem Cell Therapy: Exploring the use of stem cells to replace damaged retinal cells.
• Gene Therapy: Investigating genetic treatments to prevent or slow the progression of AMD.
• New Medications: Developing new drugs to treat both dry and wet AMD more effectively.