In the latest offshoot of the Dry Eye Assessment and Management (DREAM) study, researchers upped their stance that omega-3 fatty acids don’t help improve symptoms of dry eye disease by suggesting lower systemic levels of fish oil aren’t linked to worse symptoms and most signs of the condition.

In the current investigation, researchers analyzed patients’ blood samples for omega-3 and omega-6 to evaluate the relationship between systemic omega-3 levels and signs and symptoms at baseline in the DREAM investigation. The samples were measured as relative percentage by weight among all fatty acids in erythrocytes. The study team evaluated symptoms using the ocular surface disease index, conjunctival staining, corneal staining, tear break-up time (TBUT) and Schirmer’s test with anesthesia.

The researchers found no correlation between the systemic omega-3 levels and dry eye symptoms. When assessing the signs of dry eye, investigators observed a link between lower DHA levels and higher conjunctival staining with mean scores of 3.31, 2.96 and 2.82 for low, medium and high levels of DHA, respectively. None of the other signs were associated with DHA or the other omega-3 measures.

The eligibility criteria of the DREAM Study allowed people who were taking low doses of omega-3 supplements (1,200mg) to still enroll in the study. Erythrocyte analysis showed the 134 subjects who were taking omega-3 supplements before entering the study had significantly higher systemic levels as compared with the 386 subjects who were not taking any supplements prior to the study.

However, despite the marked differences in systemic levels of omega-3 between the two groups, no statistically significant differences in severity of dry eye signs and symptoms were observed, the researchers noted.

These finding helps support the conclusion that systemic levels of omega-3 are not associated with the severity of dry eye disease and bring into question the assertion that omega-3 fatty acids are beneficial for treatment and the mechanism by which they affect dry eye, the investigators said.