If you've been diagnosed with dry eye in the last decade, you've likely been recommended fish oil/omega-3 supplements by your doctor. Multiple studies since the early 2000's had indicated that dietary omega-3 intake was both anti-inflammatory and could improve signs and symptoms of dry eye over the course of a few months. The newly published DREAM study (Dry Eye Assessment and Management Study) funded by the National Institute of Health however is making waves by calling into question prior studies showing omega supplementation's effectiveness. In fact, the DREAM study showed patients with dry eye taking omega-3 supplements achieved no better outcomes than placebo. The results are raising more questions than answers as doctors try to make sense of the study that was designed to be the largest investigation of omega supplements and dry eye to date.
About the DREAM Study
At the end of 12 months, both groups showed improvements in dry eye signs and symptoms. There were no significant differences between the omega-3 supplement group and the placebo olive oil group in average changes from baseline in the OSDI symptom score, conjunctival staining score, corneal staining score, tear break-up time, or Schirmer’s test.
Others contend that looking at omega 3 supplementation alone leaves out the vital role that anti-inflammatory omega 6 supplements (such as gamma-linolenic acid) can have in treating dry eye. A 2008 study comparing GLA omega 6 supplements versus an olive oil placebo did show statistically signficant improvement in dry eye symptom scores and assessment of contact lens comfort.
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| Recommending omega-3 supplements has been standard of care for dry eye treatment for over a decade, but new research is calling the practice into question. via |
About the DREAM Study
The DREAM study followed over 500 patients diagnosed with moderate to severe dry eye disease for over 1 year. Patients were randomly assigned to either treatment or control groups in a double blind study design. Treatment group patients were started on 3000 mg of fish-derived omega 3 supplements daily (n-3 eicosapentaeonic and docosahexaeonic acids, better known as EPA and DHA). The placebo group received 5 mg of olive oil supplements daily in identical capsules as the treatment group. Patients were evaluated for improvements in OSDI score (a standardized questionnaire to assess dry eye symptoms) over baseline at both 6 and 12 months of treatment. Improvements in conjunctival staining, corneal staining, tear break up time, and Schirmer's test were also assessed.
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| Staining of the cornea (seen here) and conjunctiva, or white of the eye, is a sign of significant dry eye disease. In these patients, the eye is so dry that cell walls are broken on the eye's surface! via |
At the end of 12 months, both groups showed improvements in dry eye signs and symptoms. There were no significant differences between the omega-3 supplement group and the placebo olive oil group in average changes from baseline in the OSDI symptom score, conjunctival staining score, corneal staining score, tear break-up time, or Schirmer’s test.
The Repercussions and Debate
When results were published in April, 2018 the eyecare world was rocked by the reveal that omega-3 supplementation performed no better than placebo on any dry eye measurement assessed. However, the interpretation of the results has been mixed and is leading to more questions than answers. Dr. Penny Asbell, a study chair of the trial and an ophthalmologist at Mount Sinai Hospital was quoted as saying definitively, "The results of the DREAM study do not support use of omega-3 supplements for patients with moderate to severe dry eye disease." Others, however do not support such a bold assertion.
One of the major knocks of the study was that all enrolled patients were allowed to continue taking any previously prescribed dry eye treatment (including over the counter artificial tears and prescriptions like Xiidra or Restasis). These treatments have clinical studies showing they improve dry eye signs and symptoms on their own over the course of several months, and would have influenced the improvement seen in patients in both treatment groups.
In statements reported in Optometry Times, however, Dr. Asbell contends the fact that patients were permitted to continue using their previously prescribed dry eye therapies is actually one of the DREAM study's strengths. "We took patients who were symptomatic despite whatever treatments they might be doing, and they were allowed to continue those treatments. It was typical of the kinds of patients I see and other clinicians see in the office every day."
Another issue with study design under contention is the selection of olive oil as the placebo. Dr. Scott Hauswirth, OD served as a clinician at a DREAM study site. While some view the equal improvement in dry eye signs and symptoms observed in patients both taking omega-3 supplements and the olive oil placebo as evidence that omega-3 supplements were ineffective, he sees the results as evidence that olive oil may actually have been treating the patients' dry eye as well. "Oil oil turned out to be a surprise performer," he told Optometry Times. "Because both oils improved dry eye signs and symptoms over the course of the trial, DREAM ended up essentially comparing two treatments."
"Olive oil is not considered [to have] a significant effect on dry eye disease," counters Dr. Asbell concerning the selection of the placebo. Olive oil has served as the placebo in clinical trials investigating the effects of omega-3 supplements for cardiovascular health and rheumatoid arthritis because it has no measurable increase in fatty acid uptake in the body. Over the course of the 1 year study, blood samples proved there was no significant impact seen in the content of oleic acid (which comprises roughly 68% of olive oil) in the fatty acids of red blood cells. Patients on omega-3 supplements did have blood sample testing proving 5 fold increases in EPA in red blood cells over placebo.
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| ScienceBasedHealth, makers of HydroEye which contains both Omega-3 and Omega-6 GLA wrote a detailed response to the DREAM study on their website citing concerns over the design and conclusion. via |
Others contend that looking at omega 3 supplementation alone leaves out the vital role that anti-inflammatory omega 6 supplements (such as gamma-linolenic acid) can have in treating dry eye. A 2008 study comparing GLA omega 6 supplements versus an olive oil placebo did show statistically signficant improvement in dry eye symptom scores and assessment of contact lens comfort.
What will be the lasting impact of the DREAM Study? Doctors are now faced with deciding if recommending omega-3 supplementation is the proper suggestion for their patients suffering with dry eye. What's promising is that all patients, on placebo or treatment, did have improvement in both their signs and symptoms of dry eye while being treated. Whether that improvement came from their continued use of artificial tears or previously prescribed dry eye medications, or was in any way impacted by the supplementation of omega-3s or olive oil is hard to tease out from the DREAM study alone. Until more information is gleaned, doctors will continue to have to make personal judgement calls on whether they think the chance that omega-3 supplements might help is evidence enough to recommend their use.
