Dry Eye Symptoms Improve With Omega-3 Supplementation, But Clinical Signs Remain

Omega-3 supplementation may improve subjective symptoms in patients with dry eye disease, according to a systematic review and meta-analysis published in Acta Ophthalmologica. However, clinical tests fail to confirm a resolution of ocular surface signs when compared with a placebo. 

Researchers performed a meta-analysis consisting of 8 randomized controlled trials and 1107 participants that compared omega-3 fatty acids with a placebo for managing dry eye symptoms. A systematic literature search was performed using combinations of the terms “dry eye syndromes,” “dry eye disease,” “keratoconjunctivitis sicca,” “omega-3,” “fatty acids,” and “polyunsaturated fatty acids” in the Cochrane Library (CENTRAL), Embase (Emtree), PubMed (MEDLINE), Scopus, and Web of Science. All participants underwent tear breakup time (TBUT) analysis, corneal staining, and Schirmer test and reported dry eye symptoms through an Ocular Surface Disease Index (OSDI) questionnaire.

Among the 8 studies included in the meta-analysis, 1 involved a 3-armed investigation comparing fish oil, krill oil, and a placebo. The remaining 7 compared omega-3 fatty acids with a placebo. All of the studies used oral supplements as an active treatment method, except for 2, which administered treatment in the form of eye drops. 

According to the report, OSDI score improved in patients using omega-3 fatty acids versus the placebo from baseline to final assessment (standardized mean difference, -0.328; 95% CI, -0.465 to -0.192). However, no improvements were noted in corneal staining, TBUT or Schirmer score with omega-3 supplementation. 

“[T]here is insufficient evidence to advise or refute the use of omega-3 fatty acids in the treatment of dry eye disease,” according to the investigators. “Given the high level of heterogeneity across all stages of the dry eye disease pathway, the results derived from this review must be considered generally inconclusive.” 

Study limitations include differences in clinical characteristics and dry eye disease definitions among the studies and high levels of statistical heterogeneity.