Age-Related Vision Loss: Four Common Causes
Jul 2009
According to the American Association for the Blind, approximately 6.5 million Americans over the age of 65 are currently experiencing some sort of vision loss. In coming years, as the country’s population ages, experts believe that number could potentially double.
The keys to preventing or delaying vision loss are proper screening and knowledge of family history. Doctors recommend regular eye examinations starting at age 40 even if you don’t have any vision problems. Comprehensive dilated eye exams are also recommended every two years after the age of 60.
Dr. John Nordlund of Retina and Glaucoma Associates in Williamsburg says vision loss can occur slowly and that in many cases, people don’t realize that damage is occuring in their eyes until it’s too late.
“A lot of eye diseases are controllable but not curable,” Nordlund explains. “It’s important to catch problems early on to prevent the most damage to your vision.”
A 2004 study by the National Eye Institute identified the four most common age-related eye diseases as glaucoma, cataracts, diabetic retinopathy and age-related macular degeneration, or AMD. The following is a brief course in these causes of age-related vision loss:
“A lot of eye diseases are controllable but not curable.”
— Dr. John Nordlund, Retina & Glaucoma Associates
Age-related Macular Degeneration
is the leading cause of blindness among adults age 50 and older. It occurs when the retina and its lower layers become damaged, resulting in distorted and blurred central vision. AMD is labeled as dry or wet; dry AMD can be diagnosed based on the presence of drusen—yellow and white deposits in the eye—during a dilated retinal examination. Wet AMD, the less common form of the disease, is characterized by the growth of new blood vessels on the retina.
Prevention:
While Nordlund says there is no exact way to prevent age-related macular degeneration, studies have pinpointed several risk factors such as smoking, obesity, high blood pressure, and a diet high in saturated fats and low in fruits and vegetables.
Treatment:
According to Nordlund, while vitamins and zinc are used to treat dry AMD, wet AMD is treated with a series of injections behind the eye that block the growth of new blood vessels.
Glaucoma
is a chronic eye disease that damages the optic nerve. Symptoms include loss of peripheral vision, sensitivity to light and poor night vision. African-Americans are at increased risk of developing glaucoma, as are those with a family history of the disease.
Prevention:
Glaucoma causes permanent damage to the eye, but early detection and treatment can minimize vision loss. Those with a family history of glaucoma or who have other risk factors should receive frequent eye examinations. During a routine eye exam, a tonometer is used to measure the pressure within the eye. The higher the pressure reading, the more likely the patient is to develop glaucoma.
Treatment:
All glaucoma treatments are aimed at lowering the intraocular pressure. Medications in the form of eye drops, along with laser procedures and surgery, can help minimize vision loss from glaucoma.
Cataracts
are caused by excess pigment in the lens of the eye, resulting in cloudy vision. “Most people [will] have cataracts by the time they are 80 years old,” says Nordlund. Symptoms can include poor night vision, sensitivity to light, and seeing distorted colors or halos around lights.
Prevention:
Studies have suggested that in addition to age, exposure to sunlight and cigarette smoking can increase one’s risk of developing cataracts. Researchers also believe that a healthy diet including fruits as well as green, leafy vegetables and other antioxidant-rich foods can offer protective benefits.
Treatment:
Unlike most causes of vision loss, cataracts can be easily treated with lens replacement surgery. “Think of it as changing a lens in a camera,” Nordlund explains. Though cataracts can be corrected with surgery, vision loss resulting from them is more significant, particularly after the age of 60, without proper screenings and routine visits to an eye doctor.
Diabetic retinopathy
is the most common diabetic eye disease and a leading cause of blindness in American adults. It is caused by changes in the blood vessels and may take years to fully develop. In some patients, blood vessels in the eye will swell and leak fluid. Common symptoms are “spiders” or “cobwebs” or tiny specks floating in the visual field, as well as blurred vision and poor night vision, among other symptoms.
Prevention:
Adults with diabetes should have an annual dilated retinal exam. Early detection of retinal damage allows effective treatment with lasers or eye medications before vision loss occurs. Those with a family history of adult-onset diabetes (also known as Type 2 diabetes) should be screened regularly. Maintaining a healthy weight can also help prevent the disease.