Purpose: To assess whether omega-3 fatty acid (FA) supplementation is more efficacious than placebo in amelioration of signs and symptoms of dry eye disease.
Methods: We performed a systematic literature search in PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases. We included randomized clinical trials comparing omega-3 FA supplementation with placebo in patients with dry eye disease. The outcome measures were dry eye symptoms, breakup time (BUT), Schirmer test, and corneal fluorescein staining. The pooled effect sizes were estimated using a random-effects model. Heterogeneity was evaluated using the Q and I tests. Sensitivity analysis and assessment of publication bias were performed. Meta-regression was performed to evaluate the source of heterogeneity.
Results: Seventeen randomized clinical trials involving 3363 patients were included. Compared with placebo, omega-3 FA supplementation decreased dry eye symptoms [standardized difference in mean values (SDM) = 0.968; 95% confidence interval (CI) 0.554-1.383; P < 0.001] and corneal fluorescein staining (SDM = 0.517; 95% CI, 0.043-0.991; P = 0.032), whereas it increased the BUT (SDM = 0.905; 95% CI, 0.564-1.246; P < 0.001) and Schirmer test values (SDM = 0.905; 95% CI, 0.564-1.246; P < 0.001). No evidence of publication bias was observed, and sensitivity analyses indicated the robustness of results obtained. Meta-regression analysis showed a higher improvement of dry eye symptoms and BUT in studies conducted in India.
Conclusions: This meta-analysis provides evidence that omega-3 FA supplementation significantly improves dry eye symptoms and signs in patients with dry eye disease. Therefore, our findings indicate that omega-3 FA supplementation may be an effective treatment for dry eye disease.