Omega-3 for Dry Eye: The DREAM Trial and Other Evidence

The DREAM trial

DREAM randomly assigned 535 people with moderate-to-severe dry eye disease to 3,000 mg a day of fish-derived EPA and DHA (349 people) or an olive oil placebo (186). After 12 months the change in the Ocular Surface Disease Index symptom score was -13.9 points with omega-3 and -12.5 with placebo (difference -1.9, 95% CI -5.0 to 1.1; not significant). Staining of the eye surface, tear break-up time and the Schirmer tear test also did not differ, and adverse events were similar. [1] NCCIH reports that 43 participants joined a 12-month extension, randomly continuing omega-3 or switching to placebo, and outcomes did not differ. [4]

Reviews of other trials

1. Dry eye symptoms

   Insufficient evidence

   2019 Cochrane review of 34 trials (4,314 adults, follow-up 1 to 12 months; over half of studies at high risk of bias in at least one way): low-certainty evidence of little to no reduction in symptoms with long-chain omega-3 versus placebo (MD -2.47, 95% CI -5.14 to 0.19) [2]

2. Tear production

   Biomarker only

   Same review: moderate-certainty evidence of a probable increase in tear production on the Schirmer test (0.68 mm in 5 minutes), which the authors did not judge clinically meaningful [2]

3. Overall conclusion

   Mixed

   The Cochrane authors saw a possible role for long-chain omega-3 in managing dry eye but called the evidence uncertain and inconsistent [2]

4. Updated meta-analysis

   Mixed

   2023 meta-analysis of 8 trials (1,107 people): improvement in symptom scores, but no improvement in corneal staining, tear break-up time or Schirmer scores; none of the trials was at low risk of bias and results varied widely [3]

Why do DREAM and the pooled reviews differ? The pooled trials were mostly smaller and varied in product, amount, severity of dry eye and outcomes measured, and the reviewers note risk of bias and inconsistency. [2][3] DREAM tested one product and amount in moderate-to-severe disease, so its result may not apply to other products or milder disease. NCCIH notes that in one review 2 of 8 studies used omega-3 eye drops rather than capsules. [4] Proper evidence not found: a large trial showing that krill oil, algal oil or omega-3 eye drops relieve dry eye; we looked at the Cochrane review, the 2023 meta-analysis and the NCCIH summary.

Diet and dry eye

The National Eye Institute lists not getting enough omega-3 fatty acids (and vitamin A) among things that may make dry eye more likely, alongside age 50 or older, being female, contact lens use and autoimmune conditions such as lupus or Sjogren syndrome. [5] That describes a risk factor; it does not show that a supplement treats dry eye. For food sources see oily fish and omega-3 from food vs supplements.