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DREAM results do not support omega-3 supplementation for dry eye disease
WASHINGTON — The results of the 1-year Dry Eye Assessment and Management trial found insufficient evidence to support patients taking oral omega-3 supplements to reduce the signs and symptoms of dry eye disease, according to a speaker here.
“This NEI-supported clinical trial shows that oral omega-3 is no better than placebo in relieving signs and symptoms of dry eye disease,” Penny Asbell, MD, study chair of the DREAM trial, said during Cornea Day at the American Society of Cataract and Refractive Surgery annual meeting.
The DREAM trial is the first large-scale, real-world, double-masked, randomized, multicenter clinical trial to study the long-term effects of omega-3 supplementation for symptomatic dry eye disease. The trial included 535 patients randomized into a treatment group or a placebo group.
The active supplement group, two-thirds of the patient cohort, received a daily dose of 3,000 mg of marine-derived omega-3 fatty acid, 2,000 mg of eicosapentaenoic acid and 1,000 mg of docosahexaenoic acid. The placebo group, one-third of the patient cohort, received 5,000 mg of olive oil, according to Asbell.
Patients who received omega-3 experienced a 13.9-point mean reduction in Ocular Surface Disease Index score at 12 months compared with a 12.5-point mean reduction in OSDI score in patients who received placebo, which was not a clinically significant difference, according to Asbell.
There were no clinically significant treatment differences between the active and placebo groups for OSDI scores, Brief Ocular Discomfort Index scores, SF-36 scores, four key signs of dry eye disease, dry eye disease treatment, and serious or nonserious adverse events, Asbell said. – by Robert Linnehan
Reference:
Asbell P. Featured lecture: Role of nutritional supplements in dry eye disease. Presented at: American Society of Cataract and Refractive Surgery annual meeting; April 13-17, 2018; Washington.
Disclosures: Asbell reports she is a consultant for Allergan, Kao Corporation, Medscape, Novartis, Perrigo, Regeneron, Santen, Scientia, Senju, Shire, Valeant and Virtuoso; and receives full or partial research funding from MC2 Therapeutics, Novartis and Valeant. She reports the DREAM trial received contributions, discounts or assistance from Access Business Group LLC, Compounded Solutions in Pharmacy, Immco Diagnostics, Leiter’s, Oculus, RPS Diagnostics, TearLab and TearScience.
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When Dr. Asbell presented the results of the DREAM study at ASCRS, it sparked quite a bit of discussion among my peers. This was a very well-designed and executed double-masked placebo-controlled study with a large number of participants spread throughout the country. At first glance, it seems to show that there is no benefit at all to using omega-3 fatty acid supplements in the treatment of dry eye. However, when you consider the control that was used, refined olive oil, the conclusion comes into question. It might be that olive oil with vitamin E is just as effective as omega-3s for treating dry eye symptoms.
Olive oil itself has proven anti-inflammatory benefits, particularly the oleocanthal component. It is a key element of the “Mediterranean diet,” which studies have shown reduces the risk for cardiovascular disease. With omega-3 supplementation showing similar risk reduction, it is not much of a stretch to believe that the health benefits of olive oil may extend to dry eye symptoms as well.
Omega-3 supplements are not the easiest treatment for patients to take. To ingest the recommended dose, it typically requires swallowing four to six “horse pills” daily. My patients often stop taking them because they leave a fishy aftertaste as well as cause belching and reflux. They can also be quite expensive, with some brands charging more than $500 for a year’s supply. After seeing the results of the DREAM study, I don’t think that I will be as inclined to recommend this treatment when I could instead advise my patients to add a few extra tablespoons of a high-quality extra virgin olive oil to their diet. Unfortunately, we might need to wait for another similar trial with a different “true” placebo to determine if omega-3s have any of the benefits that we think they do or if the modest reduction in dry eye symptoms in both groups of the DREAM study were simply a placebo effect. In the meantime, I have no doubt that the same companies producing omega-3 pills will be adding an olive oil supplement to their line of products in the near future.
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I applaud Dr. Asbell and colleagues for their work with the DREAM study, which prospectively evaluated the efficacy of oral omega-3 supplementation in dry eye patients. Based on the specifics of the study design and results, I am intrigued and perplexed.
Regarding the results, both the study omega arm and the control arm (olive oil) reduced the OSDI scores, with a greater effect seen in more severe patients. Those with an OSDI score less than 40 at baseline had a smaller reduction after 12 months (–9.2 vs. –5.9, respectively) as compared with those more symptomatic patients at baseline with OSDI greater than 40 (–17.6 vs. –17.5). To me, this clinically translates to omegas and olive oil leading to symptomatic improvement over the 12-month study, which then begs the question, “Does olive oil contain properties that can improve dry eye disease?” I do not know the answer to this. Olive oil contains omega-9 and omega-6 fatty acids, which might have an effect on the balance of pro- vs. anti-inflammatory fatty acids in the body, including linoleic acid, which is a precursor to gamma-linoleic acid (GLA), and GLA has been shown to be effective in the treatment of dry eye disease.
Regarding the study arm, the omega-3 was 3,000 mg of fish-derived n-3 eicosapentaenoic and docosahexaenoic acids. It is important to remember that there are other omegas, such as GLA, that were not included in DREAM but have been validated in seven dry eye clinical trials for the treatment of dry eye disease. GLA, an anti-inflammatory omega, is not found in fish, flax or diet.
Lastly, the study design was inclusive of all moderate to severe dry eye patients, and to simulate “real-world” dry eye patients, the omega-3 supplement was not studied in a singular fashion and patients did not stop any of their other dry eye treatments, including topical cyclosporine 0.05%, artificial tears and lid hygiene therapy. Thus, there are enough confounding factors that make it impossible to say that oral omegas are not effective. Rather, my conclusion is that not all omegas are created equally, omegas and olive oil improve dry eye symptoms, the properties of olive oil need to be further studied, and there is now a conflicting body of evidence regarding the efficacy and role of omega supplementation for dry eye patients.
Ultimately, I am not yet ready to discount the use of oral omega supplements for dry eye patients, and I anecdotally have seen and found that omega supplementation, more specifically one that is GLA-based, is an effective part of the dry eye regimen for my own patients.