Dry eye disease is a common chronic condition that causes ocular discomfort and has been linked to increased inflammation levels. Omega-3 fatty acids are often recommended as a supplement to relieve symptoms, but as the DREAM study found, they may not have much effect.

DREAM patients with moderate-to-severe DED were randomly assigned to either the n-3 fatty acid group (fish-derived) or a placebo group (refined olive oil), taking a daily oral dose of 3,000mg for 12 months.

The researchers investigated the effects of n-3 fatty acid supplementation on seven inflammatory cytokine levels in patient tears. At six months, the researchers observed a significant difference in the response between the treated and placebo groups in levels of cytokines IL-6 and IL-8. Those treated with n-3 fatty acids saw a 29% decrease in IL-6 levels, compared with a 35.2% increase in the placebo group; and a 15.7% increase in IL-8 in the n-3 fatty acid group compared with a 79.4% increase in the placebo group. However, these significant changes didn’t persist beyond 12 months of treatment.

“Changes in cytokine concentration didn’t show a consistent or expected expression pattern between placebo and treated patient groups,” the researchers noted. Their findings supported previous DED studies in which those treated with n-3 fatty acids fared similarly to those who received a placebo supplement and had similar cytokine patterns.