EPA for Dry Eyes: Does It Really Help?

meta-analysis PMID: 31847055

Quick Summary: Research suggests that omega-3 fatty acids, like EPA, might slightly improve dry eye symptoms and tear production. However, the evidence is still uncertain, and more research is needed.

What The Research Found

Scientists looked at many studies on omega-3 and omega-6 supplements for dry eye. They found:

Omega-3 (EPA and DHA) might help a little: Some studies showed a small improvement in dry eye symptoms and tear production with omega-3 supplements.

Omega-3 might be better than omega-6: When compared to omega-6 supplements, omega-3 seemed to work better for reducing dry eye symptoms.

More research is needed: The results were not always consistent, and some studies had flaws.

Study Details

Who was studied: Adults with dry eye disease.

How long: Studies lasted from one month to a year.

What they took: Participants took omega-3 or omega-6 supplements, a placebo (dummy pill), or sometimes a combination of both.

What This Means For You

Talk to your doctor: If you have dry eyes, ask your doctor if omega-3 supplements might be right for you.

Don't expect miracles: The benefits of omega-3 for dry eyes might be small.

Look for quality: If you decide to try omega-3, choose a reputable brand with a good amount of EPA and DHA.

Be patient: It might take a few weeks or months to see any improvement.

Study Limitations

Not all studies agree: Some studies showed benefits, while others didn't.

Some studies had problems: Some studies weren't designed perfectly, which can affect the results.

More research is needed: Scientists need to do more studies to be sure how well omega-3 works for dry eyes.

Key Findings

The meta-analysis evaluated 34 RCTs involving 4,314 adults with dry eye disease. Long-chain omega-3 supplements (EPA/DHA) showed low-certainty evidence for minimal reduction in symptoms (MD -2.47, 95% CI -5.14 to 0.19) and moderate-certainty evidence for increased aqueous tear production (Schirmer test MD +0.68 mm/5 min, 95% CI 0.26–1.09), though this effect was not clinically meaningful. When compared to omega-6, omega-3 demonstrated moderate-certainty evidence of symptom improvement (MD -11.88 OSDI units, 95% CI -18.85 to -4.92). However, heterogeneity and high risk of bias in over half the studies limited conclusive interpretations.

Study Design

This Cochrane meta-analysis reviewed RCTs up to February 2018 (with October 2019 updates not yet integrated). Studies compared omega-3/omega-6 supplements to placebo, no treatment, or conventional therapies in adults with dry eye. Sample sizes ranged from small trials (n=54) to larger ones (n=1,704). Follow-up durations spanned 1–12 months. Risk of bias was high in ≥50% of studies, and only 9/34 had pre-registered protocols.

Dosage & Administration

The analysis grouped long-chain omega-3 supplements (EPA and DHA), primarily derived from marine sources, but did not specify exact dosages. Administration routes and durations varied across trials, with most studies using oral supplementation. Dose ranges (if reported) were not detailed in the provided summary.

Results & Efficacy

Symptoms: Low-certainty evidence for minimal improvement with omega-3 vs. placebo (MD -2.47, 95% CI -5.14 to 0.19).
Tear Production (Schirmer Test): Moderate-certainty evidence of a small increase with omega-3 (MD +0.68 mm/5 min, 95% CI 0.26–1.09), but not clinically significant.
Tear Osmolarity: Low-certainty evidence of reduction with omega-3 (MD -17.71 mOsmol/L, 95% CI -28.07 to -7.35).
Omega-3 vs. Omega-6: Moderate-certainty evidence of superior symptom relief with omega-3 (MD -11.88 OSDI units, 95% CI -18.85 to -4.92).
Adverse Effects: Insufficient data; gastrointestinal side effects had low-certainty evidence (RR 2.34, 95% CI 0.35–15.54).

Limitations

Over half the studies had high risk of bias, and substantial heterogeneity limited data pooling for tear break-up time (TBUT) and adverse events. Most trials lacked pre-registered protocols (73.5%), raising concerns about selective reporting. Outcomes like tear osmolarity and gastrointestinal effects relied on single small studies (n=54–105). Short follow-up periods (≤12 months) precluded long-term conclusions.

Clinical Relevance

For dry eye patients, long-chain omega-3 supplements (containing EPA/DHA) may offer marginal improvements in tear production but limited symptom relief. The lack of clinically meaningful thresholds and high variability in study design suggest caution in interpreting benefits. Combining omega-3 with conventional therapy might enhance symptom management (low-certainty evidence), but larger trials are needed. Supplement users should prioritize products with standardized EPA/DHA content and consult healthcare providers, as evidence remains inconsistent and gastrointestinal risks cannot be ruled out. Future research with core outcome sets and longer follow-up could clarify efficacy.

Source: Cochrane Database Syst Rev. 2019 Dec 17;12(12):CD011115. PMID 31847055.