Good nutrition is important to keep your eyes healthy and functioning their best throughout your lifetime. Two very important eye nutrients that may reduce your risk for macular degeneration and cataracts have names you may not be familiar with: lutein (LOO-teen) and zeaxanthin (zee-ah-ZAN-thin).
Lutein and zeaxanthin are two types of carotenoids (kuh-RAH-teh-noids), which are yellow to red pigments found widely in vegetables and other plants. Though lutein is considered a yellow pigment, in high concentrations it appears orange-red.
Cooked spinach is one of the best natural food sources of lutein and zeaxanthin. Cooked spinach is one of the best natural food sources of lutein and zeaxanthin. In nature, lutein and zeaxanthin appear to absorb excess light energy to prevent damage to plants from too much sunlight, especially from high-energy light rays called blue light.
In addition to being found in many green leafy plants and colorful fruits and vegetables, lutein and zeaxanthin are found in high concentrations in the macula of the human eye, giving the macula its yellowish color. In fact, the macula also is called the "macula lutea" (from the Latin macula, meaning "spot," and lutea, meaning "yellow").
Recent research has discovered a third carotenoid in the macula. Called meso-zeaxanthin, this pigment is not found in food sources and appears to be created in the retina from ingested lutein.
Lutein and zeaxanthin appear to have important antioxidant functions in the body. Along with other natural antioxidants, including vitamin C, beta-carotene and vitamin E, these important pigments guard the body from damaging effects of free radicals, which are unstable molecules that can destroy cells and play a role in many diseases.
In addition to important eye and vision benefits, lutein may help protect against atherosclerosis (buildup of fatty deposits in arteries), the disease that leads to most heart attacks.
Eye Benefits of Lutein and Zeaxanthin
It is believed that lutein, zeaxanthin and meso-zeaxanthin in the macula block blue light from reaching the underlying structures in the retina, thereby reducing the risk of light-induced oxidative damage that could lead to macular degeneration (AMD).
A number of studies have found that lutein and zeaxanthin either help prevent AMD or may slow progression of the disease:
Research published in Nutrition & Metabolism found that a nutritional supplement containing meso-zeaxanthin, lutein and zeaxanthin effectively increased the optical density of the macular pigment in eyes of the majority of human subjects. The macular pigment is believed to offer protection against the development of macular degeneration.
Studies published in American Journal of Epidemiology, Ophthalmology and Archives of Ophthalmology found higher levels of lutein and zeaxanthin in the diet are associated with a lower incidence of AMD.
Two studies published in Investigative Ophthalmology and Visual Science found that eyes with greater levels of macular pigments were less likely to have or develop macular degeneration.
In a research article published in Archives of Biochemistry and Biophysics in August 2010, the study authors conclude that lutein, zeaxanthin and meso-zeaxanthin filter short-wavelength light and prevent or reduce the generation of free radicals in the retinal pigment epithelium and choroid. They also suggest that a mixture of these carotenoids are more effective than any one of the individual xanthophylls at the same total concentration.
Despite the findings of these studies, some experts note that other research fails to show a relationship between the dietary intake or blood levels of lutein and zeaxanthin and a person's risk of developing AMD over time. Furthermore, they say it is premature to recommend lutein or zeaxanthin supplements until large, well-controlled studies support the benefits of these xanthophylls in preventing macular degeneration.
Such evidence may soon be available. The National Eye Institute (NEI) is sponsoring a second Age-Related Eye Disease Study (AREDS) to evaluate the effect of lutein and zeaxanthin and two omega-3 fatty acids (EPA and DHA) on the progression of advanced macular degeneration and/or moderate vision loss in people at moderate to high risk for AMD progression.
The study, called AREDS2, will evaluate the effect of a daily nutritional supplement containing 10 mg of lutein and 2 mg of zeaxanthin versus a placebo among subjects between the ages of 50 and 85 years. The study began in September 2006 and is estimated to be completed in December 2012.
The first NEI-sponsored AREDS, a 10-year study completed in 2006, found that a daily supplement containing high levels of several antioxidants and zinc reduced the risk of developing advanced AMD by about 25 percent.
The multivitamin supplement used in the first AREDS contained:
Vitamin C - 500 mg
Vitamin E - 400 IU
Beta-carotene - 15 mg (equivalent of 25,000 IU of vitamin A)
Zinc (as zinc oxide) - 80 mg
Copper (as cupric oxide) - 2 mg
In addition to protecting the macula, lutein and zeaxanthin also may reduce the risk of cataracts. Recent studies published in Archives of Ophthalmology have found that healthy diets with high levels of lutein, zeaxanthin and other carotenoids were associated with a lower risk and prevalence of cataracts in women.
Foods Containing Lutein and Zeaxanthin
The best natural food sources of lutein and zeaxanthin are green leafy vegetables and other green or yellow vegetables. Among these, cooked kale and cooked spinach top the list, according to the U.S. Department of Agriculture (USDA).
Non-vegetarian sources of lutein and zeaxanthin include egg yolks. But if you have high cholesterol, you're much better off getting most of these yellow nutrients from fruits and vegetables.
Lutein and Zeaxanthin Supplements
Because of the apparent eye and cardiovascular benefits of lutein and zeaxanthin, many nutritional companies have added these xanthophyll carotenoids to their multiple vitamin formulas. Others have introduced special eye vitaminsthat are predominantly lutein and zeaxanthin supplements.
There currently is no Recommended Dietary Allowance (RDA) or Recommended Daily Intake (RDI) for lutein or zeaxanthin, but some experts say you should ingest at least 6 milligrams (mg) of lutein per day for beneficial effects.
It remains unclear how much lutein and zeaxanthin is needed daily for adequate eye and vision protection. Also, it is unknown at this time whether supplements have the same effect as lutein and zeaxanthin obtained through food sources.
There are no known toxic side effects of taking too much lutein or zeaxanthin. In some cases, people who eat large amounts of carrots or yellow and green citrus fruits can develop a harmless yellowing of the skin called carotenemia. Though the appearance of the condition can be somewhat alarming and may be confused with jaundice, the yellow discoloration disappears by cutting back on consumption of these carotenoid-rich foods. (Carotenemia also can be associated with over-consumption of carotenoid-rich nutritional supplements.)
Zeaxanthin Improved Vision in Elderly in Recent Study
— The Zeaxanthin and Visual Function Study has found that zeaxanthin can improve vision in night driving and recognition of fine detail.
The study was of 60 veterans with early age-related macular degeneration who consumed 8 mg per day of dietary zeaxanthin for a year. The subjects improved in their night driving, and a number of their blind spots disappeared. Also, their fine detail recognition improved on average by 1.5 lines or 8.5 letters on an eye chart.
A report of the study appeared in the November issue of the journal Optometry.
These articles provided courtesy of All About Vision;
Ptosis (Drooping Eyelid)
By Judith Lee and Gretchyn Bailey; reviewed by Vance Thompson, MD
Ptosis (pronounced "TOE-sis") refers to drooping of an upper eyelid of one or both eyes. The droop may be barely noticeable, or the lid can descend over the entire pupil. Ptosis can affect both children and adults, but usually occurs because of aging.
Ptosis Symptoms and Signs
The most obvious sign of ptosis is the drooping eyelid. Depending on how severely the lid droops, people with ptosis may have difficulty seeing. Sometimes people tilt their heads back to try to see under the lid or raise their eyebrows repeatedly to try to lift the eyelids.
The degree of droopiness varies from one person to the next. If you think you may have ptosis, compare a recent photo of your face with one from 10 or 20 years ago, and you'll likely see a difference in the eyelid skin.
Ptosis can look similar to dermatochalasis, a group of connective tissue diseases that cause skin to hang in folds. These diseases are associated with less-than-normal elastic tissue formation. Your eye doctor should be able to tell whether or not this is the cause of your drooping eyelids.
A droopy eyelid makes it more difficult to open your eye fully, which can interfere with your vision.
What Causes Ptosis?
Ptosis can be present at birth (congenital ptosis) or develop due to aging, injury or an aftereffect of cataract surgery or other corrective eye surgery.
This condition also can be caused by a problem with the muscles lifting the eyelid, called levators. Sometimes a person's facial anatomy causes difficulties with the levator muscles.
An eye tumor, neurological disorder or systemic disease like diabetes are other causes of drooping eyelids.
Ptosis Treatment
Surgery usually is the best treatment for drooping eyelids. Your surgeon tightens levator muscles to lift eyelids, giving you improved vision and appearance. In very severe cases involving weakened levator muscles, your surgeon attaches the eyelid under the eyebrow. This allows the forehead muscles to substitute for levator muscles in lifting the eyelid.
After surgery, the eyelids may not appear symmetrical, even though the lids are higher than before surgery. Very rarely, eyelid movement may be lost.
It is important to choose your surgeon carefully, since poorly done surgery could result in an undesirable appearance or in dry eyes from lifted eyelids not closing completely.
Before agreeing to ptosis surgery, ask how many procedures your surgeon has done. Also ask to see before-and-after photos of previous patients, and ask if you can talk to any of them about the experience
Eyelid News
Raised, Yellow Patches on Eyelids Could Indicate Heart Problems
— Do you have raised, yellowish patches on your upper or lower eyelids? If so, you may have a higher risk for cardiovascular problems and you should get a comprehensive physical exam, says a recent study of 12,745 people in the Copenhagen City Heart Study.
These patches (the medical term for them is xanthelasmata) are actually cholesterol deposits, and so are those small white or gray rings that can appear around the cornea (arcus corneae). But according to researchers at the University of Copenhagen, about half of people who have either or both conditions don't show high cholesterol in a blood test.
In the study, men between 70 and 79 who had xanthelasmata had a 53 percent increased risk of having a heart attack, developing heart disease or dying within a 10-year period, versus a 41 percent risk for men without xanthelasmata. For women, the figures were 35 percent versus 27 percent.
However, the presence of arcus corneae was not significant in predicting heart attack or heart disease. Findings appeared in September on the British Medical Journal website.
Regular vitamin C intake helps prolong proper retinal cell function, according to a study in the June 29 issue of the Journal of Neuroscience. “We found that cells in the retina need to be ‘bathed’ in relatively high doses of vitamin C, inside and out, to function properly,” says author Henrique von Gersdorff, Ph.D., senior scientist at the Oregon Health & Science University in Portland. “Because the retina is part of the central nervous system, this suggests that there’s likely an important role for vitamin C throughout our brains, to a degree we had not realized before.”
Using goldfish eyes, the researchers noted that GABA-type receptors (receptors that respond to neurotransmissions) in the retinal cells stopped functioning properly when vitamin C was removed. Considering that retinal cells are a form of brain cell, the researchers postulated that GABA receptors elsewhere in the brain also require vitamin C for proper function. They concluded that because vitamin C is a natural antioxidant, it likely helps to preserve and protect both brain and retinal cells from premature breakdown.
These findings also could have major clinical implications for patients with glaucoma and epilepsy, because both conditions are induced by nerve cell dysfunction in the retina and brain secondary to improper GABA receptor function. “For example, maybe a vitamin C-rich diet could be neuroprotective for the retina and for people who are especially prone to glaucoma,” says Dr. von Gersdorff.
Calero CI, Vickers E, Moraga Cid G, et al. Allosteric modulation of retinal GABA receptors by ascorbic acid. J Neurosci. 2011 Jun 29;31(26):9672-82.
Chicago—With the approach of the school year, Prevent Blindness America (PBA) has declared August as Children's Eye Health and Safety Awareness month and is encouraging parents to “make sure every child takes the test that may help them pass all the rest.”
According to PBA, a key part of students’ success starts with healthy eyesight in the classroom; a child's ability to see the blackboard and the words on a page clearly is critical to his or her learning experience. PBA noted that children may not realize they have problems with their vision because they think how they see is how everyone else sees. They learn to compensate for their vision problems without fixing them, which can lead to more problems in school and later in life. Some students’ vision issues even may be misdiagnosed as a learning disability or behavioral problem when they may simply have vision impairment. This confusion can be eliminated by taking a child for a certified vision screening or an eye exam.
“Vision problems affect one in four school-aged children. We want all parents to make sure their child's eye problems do not go unnoticed this school year,” said Hugh R. Parry, president and chief executive officer of PBA. “A child should not have to struggle in school because of an undetected vision problem.”
PBA is also encouraging parents to learn more about how to keep their children's eyes healthy. The association has created “Star Pupils,” a free program specifically designed to educate parents on what they can do to ensure healthy eyesight for their children. Parents can visit this website to receive free information on everything from common eye conditions in children to tips on how to protect eyes from injury while playing sports.
Glaucoma refers to a category of eye disorders often associated with a dangerous buildup of internal eye pressure (intraocular pressure or IOP), which can damage the eye's optic nerve that transmits visual information to the brain.
With untreated or uncontrolled glaucoma, you might eventually notice decreased ability to see at the edges of your vision (peripheral vision). Progressive eye damage could then lead to blindness.
In fact, glaucoma creates at least some vision loss in more than half of the approximately 2.5 million Americans estimated to have the eye disease and is the second leading cause of blindness.
Glaucoma Symptoms
Glaucoma often is called the "silent thief of sight," because most types typically cause no pain and produce no symptoms until noticeable vision loss occurs.
For this reason, glaucoma often progresses undetected until the optic nerve already has been irreversibly damaged, with varying degrees of permanent vision loss.
But with acute angle-closure glaucoma, symptoms that occur suddenly can include blurry vision, halos around lights, intense eye pain, nausea and vomiting. If you have these symptoms, make sure you see an eye care practitioner or visit the emergency room immediately so steps can be taken to prevent permanent vision loss.
Diagnosis, Screening and Tests for Glaucoma
During routine eye exams, a tonometer is used to measure your intraocular pressure, or IOP. Your eye typically is numbed with eye drops, and a small probe gently rests against your eye's surface. Other tonometers send a puff of air onto your eye's surface.
Your eye pressure (intraocular pressure) will be measured with a tonometer. Some tonometers blow a puff of air onto your eye's surface. Others rest gently against the surface of your eye, which will be numbed with eye drops. (Image: National Eye Institute)
Glaucoma can be very destructive to your vision; in fact, it's the second-leading cause of blindness in the United States.
An abnormally high IOP reading indicates a problem with the amount of fluid (aqueous humor) in the eye. Either the eye is producing too much fluid, or it's not draining properly.
Normally, IOP should be below 21 mmHg (millimeters of mercury) — a unit of measurement based on how much force is exerted within a certain defined area.
If your IOP is higher than 30 mmHg, your risk of glaucoma damage is 40 times greater than someone with an IOP of 15 mmHG or lower.* This is why glaucoma treatments such as eye drops are designed to keep IOP low.
Other methods of monitoring glaucoma involve the use of sophisticated imaging technology — such as scanning laser polarimetry (SLP), optical coherence tomography (OCT) and confocal scanning laser ophthalmoscopy — to create baseline images and measurements of the eye's optic nerve and internal structures.
Then, at specified intervals, additional images and measurements are taken to make sure no changes have occurred over time that might indicate progressive glaucoma damage.
Visual field testing is a way for your eye doctor to determine if you are experiencing vision loss from glaucoma. Visual field testing involves staring straight ahead into a machine and clicking a button when you notice a blinking light in your peripheral vision. The visual field test may be repeated at regular intervals to make sure you are not developing blind spots from damage to the optic nerve or to determine the extent or progression of vision loss from glaucoma.
Gonioscopy also may be performed to make sure the aqueous humor (or "aqueous") can drain freely from the eye. In gonioscopy, special lenses are used with a biomicroscope to enable your eye doctor to see the structure inside the eye (called the drainage angle) that controls the outflow of aqueous and thereby affects intraocular pressure. Ultrasound biomicroscopy is another technique that may be used to evaluate the drainage angle.
Watch this video that explains what glaucoma is and who is at risk for the disease. (Video: National Eye Institute)
Types of Glaucoma
The two major types of glaucoma are chronic or primary open-angle glaucoma (POAG) and acute angle-closure glaucoma. The "angle" in both cases refers to the drainage angle inside the eye that controls aqueous outflow. Other variations include normal-tension glaucoma, pigmentary glaucoma, secondary glaucoma and congenital glaucoma.
Primary open-angle glaucoma(POAG). About half of Americans with chronic glaucoma don't know they have it. This common type of glaucoma gradually reduces your peripheral vision without other symptoms. By the time you notice it, permanent damage already has occurred.
If your IOP remains high, the destruction caused by POAG can progress until tunnel vision develops, and you will be able to see only objects that are straight ahead.
Angle-closure glaucoma. Angle-closure or narrow-angle glaucoma produces sudden symptoms such as eye pain, headaches, halos around lights, dilated pupils, vision loss, red eyes, nausea and vomiting.
These signs may last for a few hours, then return again for another round. Each attack takes with it part of your field of vision.
Normal-tension glaucoma. Like POAG, normal-tension glaucoma (also termed normal-pressure glaucoma, low-tension glaucoma or low-pressure glaucoma) is an open-angle type of glaucoma that can cause visual field loss due to optic nerve damage. But in normal-tension glaucoma, the eye's IOP remains in the normal range.
Also, pain is unlikely and permanent damage to the eye's optic nerve may not be noticed until symptoms such as tunnel vision occur.
The cause of normal-tension glaucoma is not known. But many doctors believe it is related to poor blood flow to the optic nerve. Normal-tension glaucoma is more common in those who are Japanese, are female and/or have a history of vascular disease.
Pigmentary glaucoma. This rare form of glaucoma is caused by pigment deposited from the iris that clogs the drainage angle, preventing aqueous humor from leaving the eye. Over time, the inflammatory response to the blocked angle damages the drainage system.
You are unlikely to notice any symptoms with pigmentary glaucoma, though some pain and blurry vision may occur after exercise. Pigmentary glaucoma affects mostly white males in their mid-30s to mid-40s.
Secondary glaucoma. Symptoms of chronic glaucoma following an eye injury could indicate secondary glaucoma, which also may develop with presence of eye infection, inflammation, a tumor or an enlarged cataract.
Congenital glaucoma. This inherited form of glaucoma is present at birth, with 80 percent of cases diagnosed by age one. These children are born with narrow angles or some other defect in the drainage system of the eye.
It's difficult to spot signs of congenital glaucoma, because children are too young to understand what is happening to them. If you notice a cloudy, white, hazy, enlarged or protruding eye in your child, consult your eye doctor. Congenital glaucoma typically occurs more in boys than in girls.
Glaucoma Treatments
Treatment can involve glaucoma surgery, lasers or medication, depending on the severity. Eye drops with medication aimed at lowering IOP usually are tried first to control glaucoma.
Because glaucoma often is painless, people may become careless about strict use of eye drops that can control eye pressure and help prevent permanent eye damage.
In fact, non-compliance with a program of prescribed glaucoma medication is a major reason for blindness caused by glaucoma.
If you find that the eye drops you are using for glaucoma are uncomfortable or inconvenient, never discontinue them without first consulting your eye doctor about a possible alternative therapy.
Eye Exam News Money Saved When Eye Doctors Detect Systemic Diseases Early, Says Study
May 2, 2011 — A recent study found that eye doctors sometimes noticed certain systemic conditions before their patients' other healthcare providers did. For high cholesterol, this occurred 65 percent of the time. For diabetes, it was 20 percent of the time, and for hypertension, it was 30 percent of the time.
Eye doctors have an unobstructed view of the eyes' blood vessels, which is where they can see signs of these chronic conditions.
VSP Vision Care, a vision benefits company, commissioned the study, which was applied to its 56 million members to determine the cost savings due to early treatment because of their eye exam.
65 percent of the 2.2 million members with high cholesterol (1.5 million) received early treatment, for a two-year savings of $1.7 billion. 20 percent of 1.5 million members with diabetes (296,800) received early treatment, for a two-year savings of $827 million. 30 percent of 2.2 million members with hypertension (667,800) received early treatment, for a two-year savings of $2 billion. Human Capital Management Services Group conducted the study for VSP Vision Care.
Another Reason To Eat More Fish: Lower Risk of Macular Degeneration for Women
BOSTON, March 2011 — You may want salmon, mackerel, herring or tuna on your menu at least once a week if you want to reduce your risk for age-related macular degneration (AMD).
Researchers at Brigham and Women's Hospital and Harvard Medical School followed up on 38,022 women during the 10 years after data had been collected on them for the Women's Health Study.
After adjustments for factors including age, they found that women who consumed the most DHA (an omega-3 fatty acid found in fish) had a 38 percent lower risk of developing AMD than those who consumed the lowest amount of DHA. They found similar results for EPA, another omega-3 fatty acid, as well as for consumption of both acids together.
Having one or more servings of fish per week produced a 42 percent lower risk of AMD, compared with less than one serving per month. Canned tuna and dark-meat fish were the primary types of fish that produced this lower risk.
The omega-6 fatty acids linoleic acid and arachidonic acid were also evaluated. Higher intake of linoleic acid, found in many fruit and vegetable oils such as safflower oil, grapeseed oil and corn oil, was associated with a higher risk of AMD, but not significantly so.
The study report appeared online in Archives of Ophthalmology on March 14.
This article was recently posted on Sight Nation. This really is amazing technology and provides great hope for people with end-stage macular degeneration and poor vision. The telescope is impanted in the pupil area.
VisionCare's Macular Degeneration Telescope Implant Named 'Best of What's New' 2010 by Popular Science Magazine
SARATOGA, Calif.— VisionCare Ophthalmic Technologies, Inc., a developer of advanced visual prosthetic devices, announced the Implantable Miniature Telescope, designed to improve vision in patients with end-stage age-related macular degeneration (AMD), was named "Best of What's New" 2010 by Popular Science magazine.
VisionCare's first-of-kind telescope implant, designed by Dr. Isaac Lipshitz, is integral to a new patient care program, CentraSight, for treating patients with end-stage macular degeneration, the most advanced form of AMD and the leading cause of blindness in older Americans in the U.S., according to the announcement. Smaller than a pea, the telescope implant earned U.S. Food and Drug Administration (FDA) approval on July 1, 2010 and is the first and only treatment for AMD patients who progress to end-stage disease.
Through a rigorous screening process, Popular Science magazine evaluated companies and products in 11 different categories to identify innovations with potential to positively impact the future and push the envelope of what was not thought to be possible in the previous 12 months. Annually, the magazine’s Best of What's New honors the top 100 innovations. VisionCare's telescope implant is a Best of What's New winner in the health category in the December issue of the magazine.
