Age-related macular degeneration (AMD) is a leading cause of vision loss in people over the age of 50. It affects the macula, which is the small, central part of the retina responsible for sharp, detailed vision, such as reading, driving, and recognizing faces. AMD does not cause total blindness, but it can lead to severe central vision loss, making it difficult to perform everyday tasks.
Types of AMD:
There are two main types of age-related macular degeneration:
1. Dry AMD (Non-Neovascular AMD)
This is the most common form of AMD, accounting for about 85-90% of cases. Dry AMD develops slowly over time and is caused by the gradual thinning of the macula and the accumulation of waste material (called drusen) under the retina.
Symptoms of Dry AMD:
- Blurry or distorted vision: A gradual decrease in central vision, making it harder to see fine details.
- Difficulty with tasks like reading, sewing, or recognizing faces.
- The central vision may appear dim or faded, while peripheral vision remains intact.
- Visual distortions, such as straight lines appearing wavy (metamorphopsia).
Dry AMD usually progresses slowly, and many people don't experience significant vision loss in the early stages. However, if untreated, it can advance to the wet form (described below).
2. Wet AMD (Neovascular AMD)
Wet AMD is less common but much more severe. It occurs when abnormal blood vessels grow beneath the retina and leak fluid or blood into the macula. This leads to rapid damage to the macula and acute vision loss.
Symptoms of Wet AMD:
- Sudden vision changes: Rapid decrease in central vision, often leading to significant distortion.
- Straight lines appear wavy (metamorphopsia).
- Dark spots in the central vision (scotoma).
- Blurry or unclear central vision.
Risk Factors for AMD:
Several factors increase the likelihood of developing age-related macular degeneration:
- Age: Risk increases significantly after age 65.
- Family history: Genetic predisposition plays a role.
- Race and ethnicity: More common in Caucasians.
- Smoking: Damages blood vessels and accelerates progression.
- Diet and lifestyle: Poor diet increases risk.
- Obesity: Higher body weight is a risk factor.
- Sunlight exposure: Prolonged UV exposure without protection.
Symptoms of AMD:
In its early stages, AMD may not cause noticeable symptoms. However, as it progresses, individuals may experience the following:
- Blurred vision in the center of the visual field.
- Distorted or wavy vision (metamorphopsia).
- Difficulty seeing at night or in dim lighting.
- A dark or empty area in the center of vision.
- Loss of sharp, central vision.
Treatment for AMD:
Treatment for AMD depends on whether the condition is dry or wet.
Dry AMD Treatment:
Currently, there is no cure for dry AMD, but lifestyle changes and early intervention
can slow its progression:
- Antioxidant-rich diet: Leafy greens, omega-3 rich fish, and fruits/vegetables. AREDS formula supplements may help slow progression.
- Regular monitoring: Routine eye exams to track changes.
- Low vision aids: Magnifiers, large print materials, and digital devices to assist daily activities.
Wet AMD Treatment:
Wet AMD progresses quickly and requires more intensive treatment to prevent or slow vision loss:
- Anti-VEGF injections: Medications like Lucentis, Eylea, and Avastin block abnormal blood vessel growth.
- Photodynamic therapy (PDT): Light-sensitive drug and laser treatment to close abnormal vessels.
- Laser surgery: Destroys abnormal vessels (less common now).
- Steroid injections: To reduce inflammation and macular swelling in some cases.
