Macular degeneration, also known as age-related macular degeneration (AMD) is a common condition in older adults and the leading cause of vision loss and blindness in people over the age of 65.
Macular degeneration affects the macula, the part of the retina responsible for the crisp, detailed vision needed for reading or driving. As we age, the tissue in the eye responsible for central vision slowly begins to deteriorate which can significantly affect a patient's quality of life.
Macular degeneration can be classified as either wet (neovascular) or dry (non-neovascular). Dry macular degeneration is the more common diagnosis, and is considered to be an early stage of the disease. This type of the disease usually develops as a result of aging and thinning of macular tissues and the depositing of pigment within the macula.
Only about 10% of patients see their condition progress to the more advanced and damaging wet macular degeneration. In wet macular degeneration, new blood vessels develop beneath the retina and cause a leakage of blood and fluid. This leakage can lead to permanent damages in the central vision and the creation of blind spots. Although less common, wet macular degeneration accounts for 90% of the blindness caused by all cases of this condition.
Patients with macular degeneration may notice gradual changes to their vision, including shadowy areas in the central vision, or fuzzy and distorted vision. These areas grow larger as the disease progresses, and can eventually turn into blind spots. Patients may also have difficulty seeing color and fine details.
If the disease progresses to the wet form, patients may also see straight lines as wavy. With wet macular degeneration, central vision loss can occur rapidly, sometimes in as little as a few days or weeks.
Your doctor may be able to detect early signs of macular degeneration, before any symptoms occur, through a regular eye exam. Any signs of this condition can be further confirmed by testing your central vision with an Amsler grid test. Regular eye exams are important in detecting macular degeneration and other serious eye conditions as early as possible, so that permanent side effects can be avoided.
Causes and Risk Factors
Many cases of macular degeneration are a result of aging and the natural deterioration of the eye tissue that is needed for clear vision. This disease can also be related to a genetic factor in patients who have a gene variant known as complement factor H. Nearly half of the blinding cases of macular degeneration are linked to this genetic deficiency.
Macular degeneration is most common in females and whites, and the risk for all patients increases with age. This condition is the leading cause of blindness in the US for patients over the age of 65. Over 14% of adults between the ages of 70 and 79 have been diagnosed with advanced or intermediate age-related macular degeneration.
Other factors that may increase your risk of macular degeneration include:
- High fat diet
- Prolonged sun exposure
- High blood pressure
- Lighter eye color
- Side effects of certain drugs
Patients can minimize their risk of macular degeneration by practicing a healthy, active life and getting regular eye exams. It is important for all patients to exercise regularly, avoid smoking, and eat a balanced diet that includes foods known to preserve vision and prevent eye diseases.