2010-7-30 1:01:06
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Dry Eye
Omega-3 acids thought to benefit dry-eye patients


by Vanessa Caceres EyeWorld Contributing Editor
 
 

 

 

How flaxseed oil may work
to counteract dry eye after
LASIK.


There was no change in
dry-eye grading with
the Kowa interferometer
at three months after LASIK.


Punctate epitheliopathy and
thick lipid secretions
post-LASIK.
Source: Colin C.K. Chan, M.D.

More clinical research needed, physicians say

Omega-3 acids may help alleviate some of your dry-eye patients’ symptoms.
Still, the quantity of omega-3 acids that patients need for lasting benefits are under investigation.
The connection between nutrition and dry eye has only recently been spotlighted. Ophthalmologists tend to focus on clinical concerns versus nutritional treatment, physicians said.
Yet with the press that surrounds the overall nutritional value of omega-3 fatty acids—including the link between increased consumption of omega-3 acids and a lower incidence of dry eye—the latest research is hard to ignore, said Robert L. Latkany, M.D., Dry Eye Clinic, New York Eye and Ear Infirmary, New York.
The possibility of nutritional healing will intrigue patients that want to avoid medicine when possible, Dr. Latkany said. “Some patients like medicine but others want this [kind of information]. Those patients love to hear dietary suggestions,” he said.
Here is a roundup of some of research from physicians that have explored dry eye and the omega-3 connection.

Omega-3 benefits


Much of the research thus far has focused on omega-3 versus omega-6 fatty acids and how they are linked to the incidence of dry eye. Omega-3 acids are found in walnuts and oily, cold, dark fish such as tuna and salmon. Omega-6 acids are found in meat, canola and corn oil, and margarine. Although both kinds of fats are needed to function, omega-3 acids are healthier than the omega-6 acids, said James McCulley, M.D., professor and chair of ophthalmology, University of Texas Southwestern Medical Center, Dallas. Although humans evolved on a diet with an omega-6 to omega-3 acid of one, omega-6 consumption in the typical Western diet can outweigh omega-3 acids by 16 times, according to a study from the October 2002 issue of Biomedicine and Pharmacotherapy.
“We know our diet is relatively deficient in omega-3 fatty acids. It’s analogous to good and bad cholesterol, where the omega 6 is the bad cholesterol and the omega-3 is the good cholesterol. We need both, but we need the ratio to be appropriate,” Dr. McCulley said.
Omega-3 acids may benefit dry eye by reducing inflammatory activity in the body and by possibly altering the lipid profiles of the meibomian glands. Some components of the omega-3 acids are thought to stimulate aqueous tear secretion.
“Scientific research over the past decade has shown that specifically targeted nutritional supplements can restore function to the glands that provide lubrication to the eye. This includes both omega GLA as well as omega 3 EPA,” said Spencer P. Thornton, M.D., president of South Carolina-based Biosyntrx, which makes the dry-eye nutritional capsule BioTears.

Studies and anecdotal reports


A study published last year in the American Journal of Clinical Nutrition, led by Biljana Miljanovic, M.D., Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, and fellow investigators further connected omega-3 acids to dry eye. Investigators used a food-frequency questionnaire with 32,470 women ages 45 to 84 participating in the Women’s Health Study, which is assessing risk factors related to cardiovascular disease and cancer.
After adjusting for demographics, hormone therapy, and total fat intake, investigators found different dietary patterns in the 1,546 women with clinically diagnosed dry eye versus the rest of the group.
“Women with a higher intake of [omega-3 fatty acids] tended to have a lower risk of dry-eye syndrome than did women with a lower intake,” the investigators wrote. They also found the participants to be at a higher risk for dry-eye syndrome if they had a higher dietary consumption of omega-6 acids. Increased tuna consumption—at least five to six times a week—seemed to decrease the risk for dry eye in the study, compared with the participants who ate tuna only once a week or less frequently.
Another study published in the February 2003 issue of the European Journal of Clinical Nutrition found that patients with Sjögrens syndrome had a lower intake of omega-3 acids.
Those who treat dry eye find the results from the studies intriguing but want to see more information. “These studies need to be backed with clinical data, which is currently lacking,” said Colin C.K. Chan, M.D., F.R.A.N.Z.C.O., refractive and corneal surgeon, The Eye Institute, Chatswood and Bondi Junction, Australia.
Dr. Chan was involved with an omega-3-related study at the Boxer Wachler Vision Institute, Beverly Hills, which found that 3,000 mg a day of omega-3-rich flaxseed oil one week before and one week after LASIK was just as effective as doxycycline for dry eye when patients were seen three months post-op. He presented the study results at this year’s ASCRS•ASOA Symposium & Congress.
“The study found that there was no difference in dry-eye outcomes between the 79 patients treated with flaxseed oil and the 73 patients treated with doxycycline. More importantly, no patient in the flaxseed oil group had anything more than mild dry eye at three months,” Dr. Chan said.
Results are also positive with 80% to 85% of patients who use BioTears, which contains omega-3 fatty acids from fish oils, as well as GLA from black currant seed oil and the necessary co-factors to push the metabolic process and other ingredients, Dr. Thornton said. Patients usually notice a difference in their dry-eye symptoms after two or three weeks, he said.
Anecdotally, Dr. Latkany said some of his patients report good results from an omega-3-rich supplement that he developed called Dry Vites (Deep Blue See, New York). Patients can take the supplement, which is made from salmon oil and flaxseed oil, three times a day or less.
“I’ve had people come back and say their eyes feel better. They also say people tell them they’re glowing,” he said.
Dr. McCulley is overseeing an omega-3-related study to examine aqueous tear characteristics, relative tear evaporation, and meibomian secretion in 36 patients with aqueous-deficient dry eye. Half of the patients will take the omega-3-rich supplement TheraTears (Advanced Vision Research, Woburn, Mass.), while the control group will not. Dr. Chan is involved with a new study that will examine the clinical use of fish oil to treat dry eye.

Ongoing research— and some cautions

Physicians also are researching if omega-3 acids are best for dry-eye patients as part of their diet or in supplements. “The belief is that the supplements are purified,” Dr. Laktany said. Supplements that use fish oil as a source of omega-3 acids can use wild fish, a variety thought to have more nutritional benefits, he said.
“Two issues with fish oil are the contamination with heavy metals and rapid oxidation after processing. It is important to choose a fish oil product from a company that deals with those issues,” Dr. Chan said.
Flaxseed oil and fish oil can increase clotting time; patients on blood thinners such as Coumadin (warfarin sodium, Bristol-Myers Squibb, Princeton, N.J.) should speak with their family physician before using the supplements, Dr. Chan said. He also said lactating and pregnant women should avoid supplements with the omega-3 acids and vitamins A, C, and E.

Editors’ note:). Dr. Chan has no financial interests related to this article. Dr. Latkany is the developer of Dry Vites supplements. Dr. McCulley is a consultant for Alcon (Fort Worth, Texas) and has affilations with Advanced Vision Research (Woburn, Mass.). Dr. Thornton is co-founder of Biosyntrx.

Contact Information
Chan: colin.chan@vghnet.com
Latkany: 212-832-2020, relief@dryeyedoctor.com
McCulley: 214-648-3407, james.mcculley@utsouthwestern.edu
Thornton: 615-373-1236, thornton@eyecareusa.org