Omega-3 essential fatty acids therapy for dry eye syndrome: a meta-analysis of randomized controlled studies

Dry eye is a common, complex condition that can reduce ocular comfort and visual performance. The impact on quality of life has been rated as similar to the effect of moderate angina and, in more severe cases, dialysis and severe angina. This study aimed to use meta-analysis to compare omega-3 fatty acid and placebo fatty acid in the management of dry eye syndrome.

Comparative studies published until 1 June 2014 were searched through a comprehensive search of the Medline, Embase, Web of Science, and the Cochrane Library electronic databases. A systematic review and cumulative analysis of comparative studies reporting the effect of omega-3 fatty acid on dry eye syndrome was conducted. All analyses were performed using the Review Manager (RevMan) v.5 software (Nordic Cochrane Centre, Copenhagen, Denmark).

The trials involved a total of 790 participants in 7 independent studies. All the studies are published between 2007 and 2013. Meta-analysis of the 5 studies that reported data in mean SD values revealed that the tear break-up time (TBUT) was significantly greater by 1.58 s (WMD=1.58, 95% CI=0.60 to 2.55; P=0.007). Combination of all the Schirmer's test data showed that omega-3 fatty acid supplementation could significantly improve the Schirmer's test (WMD=0.74, 95% CI=0.29 to 1.19; P=0.001). However, the combination of all the OSDI test data showed that omega-3 fatty acid supplementation did not significantly improve the OSDI test results (WMD=-4.54, 95% CI=-9.85 to 0.78; P=0.09).

Based on the data included in our meta-analysis, omega-3 fatty acid was associated with better TBUT and Schirmer's. No significant differences were detected in OSDI test results. Consequently, our findings suggest that omega-3 fatty acid offers is an effective therapy for dry eye syndrome.