Philadelphia, PA—Supplementation with omega-3 fatty acids has been touted for years as an effective treatment for the more than 16 million Americans who suffer from dry eye, which can cause symptoms of burning, itching, or stinging and impair vision. 

Those recommendations from clinicians helped fuel a more than $1 billion market in the United States for omega-3 fatty acid supplements, with many formulations sold OTC, although others require a prescription or are available for purchase from a healthcare provider.

Now, a new randomized clinical trial, published in the New England Journal of Medicine and simultaneously presented at the Annual Meeting of the American Society of Cataract and Refractive Surgery in Washington, DC, demonstrates that the fish-derived supplements are no more effective than placebo at alleviating keratoconjunctivitis sicca. 

Those results came from the 3-year DREAM study, conducted by the Dry Eye Assessment and Management Study Research Group and led by researchers from the Perelman School of Medicine at University of Pennsylvania and the Icahn School of Medicine at Mount Sinai. The study, conducted at 27 universities and private practices throughout the United States, found that even the highest dose of omega-3 supplements ever tested did not improve outcomes for participants.

“Our findings provide evidence that, contrary to a long held belief in the ophthalmic community, omega-3 supplements are not significantly better than a placebo at reducing dry eye symptoms,” explained principal investigator Maureen Maguire, PhD, a professor of ophthalmology at Penn Medicine. “Many patients receiving omega-3 supplements did have substantial improvement in their symptoms, but just as many patients taking placebo had improvements.”

Enrolled in the double-blind trial were 535 participants with at least a 6-month history of moderate-to-severe dry eye; they were randomly assigned to receive either a daily dose of an omega-3 supplement—containing 2,000 mg eicosapentaenoic acid and 1,000 mg docosahexaenoic acid, the highest ever tested for treating dry eye disease—or an olive oil placebo delivered in an identical capsule.

While participants’ symptoms had improved substantially in both groups after a year, researchers found no significant difference in the degree of symptom improvement between the groups. Overall, 61% of patients in the omega-3 group and 54% of those in the control group achieved at least a 10-point improvement in their symptom score, but the difference between the groups was not statistically significant.

“The trial provides the most reliable and generalizable evidence thus far on omega-3 supplementation for dry eye disease,” said Maryann Redford, DDS, MPH, program officer for clinical research at the National Eye Institute, which funded the study. “This well-controlled investigation conducted by the independently-led Dry Eye Assessment and Management (DREAM) Research Group shows that omega-3 supplements are no better than placebo for typical patients who suffer from dry eye.”

In this study, unlike most industry-sponsored trials, all participants were allowed to continue on their previous medications for dry eye, such as artificial tears and prescription anti-inflammatory eye drops. “Omega-3s are generally used as an add-on therapy. The study results are in the context of this real-world experience of treating symptomatic dry eye patients who request additional treatment,” pointed out study chair for the trial, Penny A. Asbell, MD, of the Department of Ophthalmology at the Icahn School of Medicine at Mount Sinai in New York City.