Macular degeneration, also known as age-related macular degeneration, is the deterioration of the macula, the center portion of the retina. The macula is responsible for clarity, sharpness, and forward vision. When degenerated, blind spots or distorted vision may occur, affecting everyday tasks such as driving and reading. According to the American Optometric Association, macular degeneration is the number one cause of vision impairment in Americans age 60 and older.
Types of Macular Degeneration
The two types of macular degeneration include dry and wet. The American Health Assistance Foundation reports, “It is possible for a person to suffer from both forms, for it to affect one or both eyes, and for the disease to progress slowly or rapidly.” It is also possible for one form to change into the other.
Dry Macular Degeneration
Dry macular degeneration, in which photosensitive cells of the macula deteriorate, affects 85-90 percent of people diagnosed. This form is associated with drusen, yellow deposits, which accumulate under the retina. According to the National Eye Institute, drusen do not solely cause vision loss, but with an increase in the number or size, can raise the risk for advanced dry or even wet macular disease.
Symptoms include a blurred spot in the middle of central vision, a need for more light when reading or doing detail work, blurred or hazy vision, dimmer colors and difficulty recognizing faces.
Wet Macular Degeneration
The wet form, also known as advanced macular degeneration, can result in rapid central vision loss. In this form, fragile, irregular blood vessels develop behind the macula. If ruptured, these blood vessels can leak fluid and blood into the eye, raising the macula from its normal positioning.
Symptoms include a sudden blind spot, objects appearing small or far away, central vision loss, straight lines appearing wavy and hallucinations.
Causes and Risks
Macular degeneration develops as the eyes age, especially over the age of 60. However, the exact cause is unknown. Whites and women are more at risk than African-Americans and men. Light-colored eyes, family history and long-term exposure to sunlight are other risk factors. Lifestyle factors such as poor diet, low levels of nutrients, cardiovascular disease, smoking and obesity also raise the risk of developing macular degeneration.
Diagnosis and Treatment
To diagnose macular degeneration, an eye-care professional may perform one or several exams to determine if central vision is impaired. She may check visual acuity with an eye chart. The patient's pupils may be dilated to examine the retina and optic nerve. The doctor may use optical coherence tomography, which is noninvasive imaging to identify retinal thickening or thinning and abnormal fluid buildup. He will probably measure pressure inside the eye and use a checkerboard grid to determine wavy vision. He may inject dye into the eye to do a flourescein angiogram to detect leaking blood vessels.
Currently there is no treatment for macular degeneration. However, the National Eye Institute lists various procedures such as laser surgery, phytodynamic therapy and injections that may be used to help slow vision loss and, in some cases, improve eyesight.
Prevention
To avoid or slow macular degeneration, eat a diet rich in fruits and vegetables. Antioxidants in these foods, particularly green leafy vegetables, may be helpful. Eat fish, because omega-3 fatty acids can help reduce the risk of vision loss. Tackle preventable risks such as smoking, obesity and cardiovascular disease. Get regular eye exams and wear protective sunglasses outdoors.
