Effective Dietary Supplements For Dry Eye Symptoms

Effective Dietary Supplements For Dry Eye Symptoms

Effective Dietary Supplements for Dry Eye Symptoms

John D. Sheppard, MD, MMSc

Raising overall consumption of omega-3 essential fatty acids can reduce dry eye symptoms in appropriate patients.

The nutritional approach to alleviating dry eye will not give patients the instant relief from symptoms that they might desire, but it can play an important supportive role in their therapy. The simplest, safest, and perhaps most efficacious nutritional recommendation I can make to dry eye sufferers is that they increase their consumption of omega-3 essential fatty acids, both in food and through a daily nutritional supplement containing 1,000 mg to 3,000 mg of omega-3.

Less Inflammation

The recommendation to increase omega-3 consumption arises from the research community’s recognition within the last few years of the important role that inflammation of the lacrimal glands, the meibomian glands, and the ocular surface play in causing dry eye symptoms.¹-² Omega-3 fatty acids have been shown in the laboratory to reduce inflammation via their metabolism to eicosanoids, locally acting hormone-like lipids.³ Oily fish such as salmon and sardines are the richest source of these molecules, which are incorporated into cellular membranes in the body.

There have been no large prospective studies showing that increased consumption of omega-3 exerts an antiinflammatory effect in dry eyes, but the indirect evidence is strong. In addition to considerable basic research that has been done in this area, the Women’s Health Study of nearly 40,000 subjects found that the risk of dry eye in the women with the hig hest intake of omega-3-rich foods was 17% less than it was in those with the lowest omega-3 consumption.

Ratio Is Important

Increased consumption can inhibit production of inflammatory molecules and, in high enough amounts, serve a directly protective function. This occurs when the ratio of competing omega-6 fatty acids to omega-3 is less than 4:1.

In the Women’s Health Study, subjects with an omega-6:omega-3 ratio of 15:1 or greater were 2½ times more likely to have dry eye than were women with a ratio lower than 4:1. (The typical American diet, deficient in omega-3, has a ratio of 24:1. I advise patients to try for a ratio as close to 1:1 as possible.)

It would be difficult and economically unsupportable to do research on the relative merits of fatty acids consumed in foods versus supplemental intake, but the available supplements are derived from the natural sources so it is unlikely there would be a huge difference. Omega-3 supplementation appears to have a wide safety margin that will prevent overdosing. Rarely, patients suffer indigestion, aftertaste, or allergic reactions to fish oil.

Keeping Risk Down

Patients concerned about mercury contamination of omega-3 fish oil supplements can avoid this slight risk by buying a pharmaceutical-grade supplement. This will probably triple the price of a 60-pill bottle, which normally costs from $9-$12. Capsules containing omega-3-rich flax seed oil, primrose oil, black currant seed oil, or borage oil are other alternatives.

It will take several weeks to months for patients who try this omega-3 prescription to find out whether the approach is helping their dry eye symptoms. Its usefulness largely will depend on the etiology of each patient’s disease. Someone with an accelerated tear film break-up time due to a meibomian fatty acid deficiency is obviously an excellent candidate for omega-3 supplementation. But dry eye caused by an autoimmune condition probably would not be helped as much without concomitant blepharitis.

THE BOTTOM LINE

Although there is no dietary panacea for dry eye, omega-3 fatty acid supplements, along with changes in overall eating habits, can be recommended without reservation. Supplements and foods rich in omega-3 fatty acids are chief among these. These change the ratio of omega-3 to omega-6 fatty acids ingested, and reduce inflammation over time. This is no quick fix, but patients who can comply with the nutritional prescription usually see improvement in dry eye and in their overall health.

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John D. Sheppard, MD, MMSc, practices with Virginia Eye Consultants, Norfolk, VA. He is on the ophthalmology, microbiology, and molecular cell biology faculties of the Eastern Virginia Medical School, Norfolk, VA, where he is ophthalmology program director and clinical director of the Thomas R. Lee Center for Ocular Pharmacology. He received assistance with this article from medical writer Linda Roach.

References

1. Solomon A, Dursun D, Liu Z, et al. Pro- and anti-inflammatory forms of interleukin-1 in the tear fluid and conjunctiva of patients with dry-eye disease. Invest Ophthalmol Vis Sci. 2001;42:2283–92.
2. Wilson SE. Inflammation: a unifying theory for the origin of dry eye syndrome. Manag Care. 2003;12(suppl):14–9.
3. Grimm H, Mayer K, Mayser P, Eigenbrodt E. Regulatory potential of n_3 fatty acids in immunological and inflammatory processes. Br J Nutr. 2002;87(suppl):S59–67.
4. Miljanovic B, et al. Relation between dietary n_3 and n_6 fatty acids and clinically diagnosed dry eye syndrome in women. Am J Clin Nutr. 2005; 82: 887-93.