Learn about the causes, symptoms and different types of age-related macular degeneration.
May 23, 2016
What is age-related macular degeneration?
Age-related macular degeneration (AMD) is a common eye condition and a leading cause of vision loss among people age 60 and older.1 AMD causes damage to the macula, a small spot near the center of the retina responsible for sharp, central vision, allowing people to see objects straight ahead.2
By itself, AMD does not lead to complete blindness. However, loss of central vision can interfere with everyday activities, such as the ability to recognize faces, drive, read, write, or do activities such as cooking or fixing things around the house, or those that involve fine detail.3 There are two types of AMD - "wet" and "dry."4
Dry AMD is the most common type of macular degeneration and affects 90% of people with the condition.5 With dry AMD, cells within the macula gradually become thin or break down, which is known as atrophy. Dry AMD slowly reduces central vision and can affect color perception, and over time, can cause severe vision loss that cannot be restored.4,5 Dry AMD can affect one of both eyes. Vision loss may go unnoticed if only one eye is affected. This is because the unaffected eye may compensate for vision loss in the other eye.6
Wet AMD is less common, but it can cause more damage to central vision compared to dry AMD.6 It occurs when fluids leak from newly formed blood vessels under the macula, blurring central vision, and causing rapid and severe vision loss.4 Symptoms for wet AMD are generally quick to appear and progress.6
What are the causes and risk factors for AMD?
Age is a major risk factor for AMD, as the disease is more likely to occur after age 60. Additional risk factors include:2
High blood pressure
Family history of the disease
Race - AMD is more common among Caucasians compared to African-Americans or Hispanics/Latinos
What are the symptoms of AMD and how is it diagnosed?
As AMD progresses, loss of central vision is a common symptom. Over time, the blurred area may grow larger or blank spots may appear in a person's central vision. However, dry and wet AMD can each have different symptoms.6
Dry AMD Symptoms:6
Loss of central vision or blurriness of central vision
Need for increased lighting for near vision
Colors appear faded and less vivid
Difficulty seeing when going from bright to low light
Difficulty recognizing faces
Wet AMD Symptoms:6
Loss of central vision
Dark or blank spots within vision
Distorted vision, such as straight lines appearing crooked
Colors appear faded or less vivid – and may look differently for each eye
The size of objects appear different for each eye
AMD is diagnosed through a comprehensive eye exam.3 It's generally recommended that people over 45 have a complete eye exam every two to four years.1 Those already diagnosed with AMD should notify their eye care professional immediately if any changes in their vision are noticed.1
What are treatment options for AMD?
Scientists have found that people at high risk of developing advanced stages of AMD lowered their risk by about 25 percent when treated with a high-dose combination of vitamin C, vitamin E, beta-carotene, and zinc. While the nutrients are not a cure for AMD, and will not restore vision that's already lost, it will help in lowering the risk of developing advanced AMD.7
There are also treatment options available for wet AMD, which can generally reduce, but not eliminate, the risk of severe vision loss:3
Anti-VEGF medication injections: Medications injected in the eye can block the development of new vessels and leakage from the abnormal vessels, which cause wet AMD. Many patients have regained vision that was lost through this treatment.
Laser therapy: A high-energy laser light can sometimes be used to destroy actively growing abnormal blood vessels to prevent further leakage and bleeding.
Photodynamic therapy: A combination of a light-activated drug called a photosensitizer and a low-power, cool laser can be used to target the center of the macula. The photosensitizer drug is injected into the bloodstream and is absorbed by the abnormal blood vessels in the eye. This is followed by a cold laser, which activates the drug, closing off and damages unwanted blood vessels.