WEDNESDAY, Feb. 13 (HealthDay News) -- Eye drops containing alpha-linolenic acid (ALA) significantly reduced symptoms of dry eye syndrome in mice, a new study says.

ALA is an omega-3 fatty acid that's not made by the body and has to be obtained through diet. Dry eye, which affects about 10 million people in the United States, causes symptoms such as stinging, burning, irritation or a feeling of scratchiness. It can lead to problems with day-to-day activities such as driving and reading.

Currently, treatment options are limited in terms of effectiveness and undesirable side effects, according to background information in the study, published in the February issue of the journal Archives of Ophthalmology.

Dr. Reza Dana, a Harvard Medical School professor and Cornea Service Director at the Massachusetts Eye and Ear Infirmary, and colleagues at the Schepens Eye Research Institute tested three formulations of fatty acids: 0.2 percent ALA; 0.2 percent linoleic acid (an omega-6 fatty acid); and 0.01 percent ALA combined with 0.1 percent linoleic acid.

Some mice received once-a-day treatment with these eye drops, while other mice did not receive any eye drops. The eyes of mice treated with ALA showed a significant reversal in epithelial damage to the cornea, which is the transparent dome that covers the pupil.

"The current study for the first time demonstrates the benefit of topical application of a particular fatty acid in treating the signs of dry eye syndrome at both the molecular and cellular levels," Dana noted.

"Using topical formulations of fatty acids to treat dry eye would allow for more flexibility for treatment, including lessening side effects that patients can experience from oral intake of fatty acids. Clinical studies with topical fatty acids are being planned, which, if successful, could alter the method by which this common condition is treated," Dana said.

The study received funding from Johnson & Johnson Vision Care Inc.

More information

The U.S. National Library of Medicine has more about dry eye syndrome.