Omega-3 and dry eye
by Vanessa Caceres EyeWorld Contributing Writer
Looking at science and clinical experience
Omega-3 fatty acids seem like a cure-all for just about anything that ails patients nowadays. They're hailed for promoting better heart health, reducing inflammation, providing more lustrous hair and skin, and even promoting better mood. The question is, how beneficial are omega-3s for dry eye patients? "We're in the infancy stages of understanding what this is and what it does for dry eye," said Robert Latkany, M.D., founder and director, Dry Eye Clinic, New York Eye and Ear Infirmary, New York.
Right now, ophthalmologists are using the fledgling research that is available along with their clinical experience to decide whether or not they will recommend omega-3 supplementation to dry eye patients.
Some recent research has tried to pin down the specific effects of omega-3 supplementation on dry eye. In a pilot, double-masked study published in March 2011 in Cornea, investigators gave patients various doses of fish oil and flaxseed oil (TheraTears Nutrition, Advanced Vision Research, Woburn, Mass.) for 3 months. Investigators measured patients' subjective symptoms and tested for tear breakup time and corneal staining as well as performing other tests.
Of the 36 patients included, 70% of the patients receiving treatment became asymptomatic. In the placebo group, 37% of the symptomatic patients became asymptomatic. Schirmer's testing and fluorophotometry seemed to indicate that omega-3 use increased tear secretion, according to investigators. Although those results are promising, they only begin to reveal how omega-3 might help dry eye and which patients would benefit the most, Dr. Latkany said.
A study presented at the 2012 Association for Research in Vision and Ophthalmology (ARVO) meeting in Ft. Lauderdale, Fla., and sponsored by ScienceBased Health (Houston) focused on omega-3 and gamma-linolenic acid (GLA) therapy (HydroEye) taken for 6 months by 38 postmenopausal women who had keratoconjunctivitis sicca. The double-blind, placebo-controlled, prospective, randomized, multi- center trial found that patient self-reported symptoms by OSDI (Ocular Surface Disease Index) as well as conjucnctival impression cytology CD11c and HLA-DR inflammation biomarkers statistically significantly improved after the study duration, said lead investigator John D. Sheppard, M.D., professor of ophthalmology, microbiology, and immunology, Eastern Virginia Medical School, Norfolk, Va. The study did not seem to detect differences in corneal staining or tear breakup time, but topographic corneal surface regularity stabilized significantly with the study supplementation compared to placebo. At the 2012 ASCRS•ASOA Symposium & Congress, Frank A. Bucci Jr., M.D., founder, Bucci Laser Vision, Wilkes-Barre, Pa., presented the results from a study sponsored by Physician Recommended Nutriceuticals (PRN, Plymouth Meeting, Pa.), which makes PRN Dry Eye Omega Benefits. The multicenter, blinded, randomized study randomized 60 patients to receive the PRN product, a Nature Made omega-3 product (Pharmavite, Northridge, Calif.), or TheraTears Nutrition. Investigators measured red blood cell membrane saturation of the omega-3 products at baseline, 1 and 3 months follow-up. Investigators found that red blood cell saturation was significantly greater for the PRN product compared with the other two products.
Knowing how well an omega-3 product can be absorbed in the body is crucial in ensuring it will provide key health benefits to the eyes and elsewhere, Dr. Bucci said.
Although there have been other studies related to dry eye and omega-3 supplementation, there has yet to be a large-scale clinical trial that pinpoints how omega-3 fatty acids work to treat dry eye and what kind of dosing is appropriate. Penny A. Asbell, M.D., professor of ophthalmology, director, Cornea and Refractive Services, Department of Ophthalmology, Mount Sinai School of Medicine, New York, hopes to find those answers via a clinical trial slated to get under way with the National Eye Institute. "With omega-3 and dry eye, we have small trials but little in the way of double-masked, randomized, controlled trials," she said. The trial she is working on will look beyond the claims of omega-3 benefits for general health to show how the supplementation can benefit dry eye. "It behooves us to find out how this works," she said. The trial should also reveal more information on the epidemiology of dry eye, Dr. Asbell added.
Despite what research may find, what is key is how patients respond to omega-3 use. "It's all meaningless if patients don't feel better," Dr. Latkany said. Certain types of dry eye patients seem to benefit more than others from omega-3 supplementation. "I recommend fish oil mostly for evaporative dry eye," said Esen K. Akpek, M.D., associate professor of ophthalmology, and director, Ocular Surface Diseases and Dry Eye Clinic, Wilmer Eye Institute, Johns Hopkins University, Baltimore. "I have the clinical impression that it might work."
At Dr. Latkany's practice, which specializes in dry eye, he routinely recommends omega-3 use. Of those who take it, he estimates that 70% become asymptomatic. However, this occurs along with the use of other treatments, such as Restasis (cyclosporine ophthalmic emulsion, Allergan, Irvine, Calif.), punctal plugs, or environmental changes. "Very few patients notice a big difference from omega-3 use alone. It would be in the single digit percentage," he said.
Dr. Latkany recommends omega-3 use the most to Sjogren's syndrome patientswho typically might have dry eyes, hair, mouth, and skin. He often finds his patients have already heard about omega-3 benefits, perhaps not specifically for dry eye but for general health.
Because of the general health benefits, Dr. Sheppard recommends omega-3 fatty acids for virtually all patients. "The American diet is notoriously deficient in the high-value foods. Rather than becoming a dietitian, I just recommend it to everyone. It can't hurt, with the exceptions of seafood allergy and coagulation deficiency conditions," he said. Additionally, patients can use omega-3 both to help treat dry eye and help prevent other eye conditions such as age-related macular degenerationa condition where there is even more solid research regarding omega-3 use and prevention of disease, he said. Dr. Sheppard typically recommends 1,000 mg of omega-3 twice daily in addition to GLA supplements, although he will encourage patients to take more if they are willing and able. That dosage amount provides both eicosapentaenoic acid and docosahexaenoic acid better known as EPA and DHA, Dr. Sheppard said.
However, Dr. Sheppard also noted that patients with evaporative dry eye seem to yield the most consistent benefits. The study he presented at ARVO intentionally focused on postmenopausal females as they represent a fairly homogeneous subpopulation that could benefit significantly from supplementation, he said.
What product works best?
Practitioners seem to have personal preferences regarding specific omega-3 products. "No single study shows yet that one product works better than the other," Dr. Latkany said. "Any well-known company that purifies its product, you'll be fairly safe with it."
However, Dr. Sheppard steers patients toward pharmaceutical-grade, mercury-free supplementation. "With a cheaper version, there's more risk for contaminants. We're recommending this at a high dose, so it's essential to be safe," he said. Dr. Bucci prefers a higher quality omega-3 product that absorbs more quickly in the body, comes from fish sources versus flaxseed, and does not contain alcohol.
There has been recent talk in the popular press about krill oil as an omega-3 source that can be better absorbed by the body, Dr. Latkany said. He has seen some of his patients successfully use krill oil.
In the rare instances where a patient does not like fish oil, is allergic to it, or has another physician concerned about its use because the patient takes anticoagulant therapy, Dr. Sheppard recommends the use of flaxseed oil, which the patient can obtain as a gel cap or even sprinkle in powder form on food.
Editors' note: Dr. Akpek has no financial interests related to this article. Dr. Bucci has financial interests with PRN. Dr. Latkany has financial interests with Alcon. Dr. Sheppard has financial interests with Alcon (Fort Worth, Texas), Allergan, Bausch + Lomb (Rochester, N.Y.), Lux Biosciences (Jersey City, N.J.), Merck (Whitehouse Station, N.J.), ScienceBased Health, and Vistakon (Jacksonville, Fla.). Dr. Asbell has no financial interests related to this article.
Dry eye effects on corneal refractive procedures by Ellen Stodola EyeWorld Staff Writer
Expanding "dry eye" definitions by Michelle Dalton EyeWorld Contributing Editor
Diagnosing dry eye by Jena Passut EyeWorld Staff Writer
Treating dry eye by Vanessa Caceres EyeWorld Contributing Editor
Dry eye remains a complicated issue by Michelle Dalton EyeWorld Contributing Editor
Unraveling dry eye by Maxine Lipner Senior EyeWorld Contributing Editor