Troubling numbers recently revealed at the Prevent Blindness America "Focus on Eye Health Summit" held in Washington, D.C., in June (2012) suggest that vision problems and blindness are plaguing the population.
Consider these statistics:
- 2,069,403 people age 50 and older have late age-related macular degeneration (AMD), a 25 percent increase.
- 24,409,978 million people age 40 and older have cataracts, a 19 percent increase.
- 2,719,379 million people age 40 and older have open-angleglaucoma, a 22 percent increase.
- 7,685,237 million people ages 40 and older have diabetic retinopathy, an 89 percent increase.
As life spans lengthen and the over-40 population rises the increase in optical issues is perhaps not surprising since some—such as macular degeneration and cataracts—are largely related to age. Diabetic retinopathy (a consequence of diabetes which is a disease cause by the body's inability to convert glucose to energy) and glaucoma also increases with aging, but are associated with other factors such as poor blood sugar control in the case of diabetes and family history, or genetics for glaucoma.
According to Rajeev Ramchandran, M.D., assistant professor of ophthalmology at the Flaum Eye Institute in Rochester, NY, diabetes, which seems to be the leading cause of new cases of blindness, can be controlled—even reversed—by making better lifestyle choices. "We are seeing a large increase in diabetes because of a lack of exercise, poor diet and nutritional choices, and weight gain or obesity," says the retinal specialist. "Today there are about 25 million people with diabetes and about 8 million of them have diabetic retinopathy."
By contrast, macular degeneration is a disease of the elderly, Ramchandran says. "Usually diagnosed after age 55, macular degeneration is a gradual loss of the central vision and has long been a major cause of blindness in this country." This disease is more prevalent in the Caucasian population and is the leading cause of blindness after age 65.
Cataracts are also very common in older Americans. "A cataract is a clouding of the natural lens in the eye and everyone who lives long enough will eventually develop a cataract in his or her eyes," explains the doctor. "In the African American community, cataracts are the leading cause of vision impairment which suggests a need for more access to eye care and better education in the community about the importance of regular eye exams."
Here is a brief summary of each problem, their symptoms, and treatment:
Macular Degeneration
The macula, which allows a person to see detail, is a small area towards the back of the eye in the center of the retina. Though the exact cause of macular degeneration isn't known and the disease cannot be prevented, there does seem to be genetic and dietary components. People with AMD may notice a blurring of the central vision when reading. As the disease progresses straight lines may appear distorted. "Smoking has been linked to cardiovascular diseases, high cholesterol, hypertension, and macular degeneration," says Ramchandran. "The same things that impact your heart, impact your eyes."
Ninety percent of people with AMD have the dry form but there is no standard treatment for the problem. Wet AMD progresses more rapidly and usually results in more severe vision loss. It affects about 10 percent of people with AMD. In 2006, the FDA approved a drug called Lucentis, which has been especially beneficial for people with wet AMD. Results from a recent 2-year study showed that Lucentis halted vision loss in more than 90 percent of wet AMD cases.
Much progress has been made in understanding, predicting, and treating AMD. Some promising therapies include: retinal cell transplants, pharmaceutical therapy, nutritional therapy (studies have shown that high levels of antioxidants and zinc can reduce the risk of developing advanced AMD by 25 percent), and gene therapy. Before starting any diet or vitamin regimen, Ramchandran suggests consulting with both your primary care provider and your eye doctor.
Cataracts
By the age of 80, says the National Eye Institute, more than half of all Americans have a cataract or have had surgery to remove one. Cataracts can occur in one or both eyes but cannot be spread from one eye to the other. In addition to forming as a natural consequence of aging, researchers suspect smoking and diabetes may also contribute to the formation of cataracts. Prolonged exposure to sunlight, some types of radiation, and steroid use may also be linked to cataracts.
When a cataract starts to interfere with everyday activities such as driving or reading, you may want to consider seeing an ophthalmologist to discuss surgery, as it is an effective treatment for the problem. During surgery the cloudy lens is removed and replaced with an artificial lens. Cataracts don't lead to permanent blindness but greatly impair vision until they are surgically treated.
Glaucoma
According to the National Institutes of Health, glaucoma is the second leading cause of permanent blindness in the U.S. "Glaucoma is related to the health of nerves in the eye and may be due to the way the pressure of the natural occurring fluid in the eye affects the nerves," says Ramchandran adding that it's possible to get glaucoma even with normal pressure if that level of pressure becomes too high for one's own optic nerve. The optic nerve carries visual information from the eye to the brain.
African Americans are at increased risk of developing glaucoma; many seem to have a genetic predisposition. Diabetic patients are twice as likely to get the disease as other adults. Sadly, like cataracts there is no real prevention for the disease, but vision loss can be avoided with early diagnosis and treatment.
There are four major types of glaucoma: Open-angle (chronic) glaucoma tends to run in families and is the most common form; angle-closure (acute) glaucoma is sudden and painful; congenital glaucoma is present at birth, and secondary glaucoma can be caused by trauma to the eye, diseases such as uveitis and taking corticosteroids. In most cases the pressure build up is painless and damage to the optic nerve is slow. However, sudden pain is a medical emergency and needs to be treated as such.
Treatment depends on the type of glaucoma you have. Most people have no symptoms and once vision loss has occurred, (side vision starts to lessen with glaucoma) the damage has been done. Eye drops are usually prescribed for the treatment of open-angle glaucoma. Some people also take pills to lower pressure in the eye.
Diabetic Retinopathy
Diabetic retinopathy is damage to the blood vessels in the retina as the result of long-term diabetes. "Ninety percent of diabetic patients have some form of retinopathy after 15 years of living with diabetes," Ramchandran explains adding that diabetes is also linked to cataracts and glaucoma. "Blood sugars that aren't well controlled have detrimental effects on the eye."
Most people with diabetic retinopathy have no symptoms until the damage is severe. If you are diabetic and experience blurred vision, floaters, shadows, and poor vision at night, you may have diabetic retinopathy or another eye problem. See a specialist immediately. Laser eye surgery can be used to treat the problem however it cannot reverse the damage.
"Healthy living is the best thing to maintain eye health. Proper nutrition, access to affordable and nutritious foods, avoiding tobacco use, and quitting smoking can help maintain vision and reverse the trend toward growing vision problems," says Ramchandran. In addition, everyone should see an eye care specialist for a general eye exam at least every few years. Ramchandran recommends a complete eye exam every two years after age 40 and more often if abnormalities are present. "Early detection and treatment for many forms of eye disease can save your sight."
For more information on the data regarding vision problems in the U.S., visit the Prevent Blindness America website.
Sources:
Interview with Rajeev Ramchandran, MD
Retinal specialist and assistant professor of Ophthalmology
Flaum Eye Institute
University of Rochester Medical Center
Prevent Blindness America
http://www.preventblindness.org
Foundation Fighting Blindness
http://www.blindness.org
National Institutes of Health
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002587
