A 2008 study shows that consumption of omega-6 fatty acid may help alleviate dry eye symptoms and improve overall lens comfort in patients suffering from contact lens-associated dry eye.
Researchers evaluated the effects of oral treatment with omega-6 fatty acids in the form of evening primrose oil (EPO) on subjective symptoms, ocular surface signs and tear film characteristic in patients with contact lens-associated dry eye.
76 female soft contact lens wearers were treated for six months either with omega-6 fatty acids in the form of EPO or placebo (olive oil). The patients were given three examinations (baseline, three and six months) to test tear film characteristics (tear meniscus height, break-up time), meibomian gland function (lipid layer thickness and quality) and ocular surface parameters (hyperemia and staining). At each examination the women were given a questionnaire relating to lens comfort and dry eye symptoms.
The EPO group showed a significant improvement in the specific symptom of “dryness” at three and six months as well as a significant improvement in overall lens comfort at six months. Tear meniscus height was increased in the EPO group at six months relative to baseline, although all other objective signs were unchanged.
These findings support a 2003 study on omega-6 fatty acids which evaluated the effect of systemic linoleic acid (LA) and gamma-linolenic acid (GLA) on patients with dry eyes.
GLA is an essential fatty acid in the omega-6 family that is found primarily in plant-based oils, such as evening primrose oil, black currant seed oil, and borage seed oils. Essential fatty acids help the body’s natural ability to fight inflammation, but cannot be made in the body and must be obtained from food. LA, another omega-6 fatty acid, is found in plant oils such as safflower oil and is converted to GLA in the body.
In another trial 26 dry eye patients were divided randomly into two equal sections. One section received 28.5 mg linoleic acid and 15 mg gamma-linolenic acid twice a day for 45 days while the other control section was given a placebo for the same period.
The results? Researchers found that the therapy reduced inflammation on the surface of the eye and improved dry eye symptoms.
SOURCE: Oral Omega-6 Essential Fatty Acid Treatment in Contact Lens Associated Dry Eye. Kokke, et al. Cont Lens Anterior Eye 2008;31(3):141-6.
SOURCE: Systemic Linoleic and Gamma-Linolenic Acid Therapy in Dry Eye Syndrome With an Inflammatory Component, Barabino, et al.Cornea. 22(2):97-101, March 2003.