Omega-3 fatty acid supplements taken orally proved
no better than placebo at relieving symptoms or
signs of dry eye, according to the findings of a
well-controlled trial funded by the National Eye
Institute (NEI), part of the National Institutes of
Health. The paper was published online April 13 in
the New England Journal of Medicine.
Among patients with dry eye disease, those who were
randomly assigned to receive oral supplements
containing fish-derived n-3 eicosapentaenoic and
docosahexaenoic acids did not have significantly
better outcomes at 1 year than those who received
placebo.
Dry eye disease occurs when the film that coats the
eye no longer maintains a healthy ocular surface,
which can lead to discomfort and visual impairment.
“The trial provides the most reliable and
generalizable evidence thus far on omega-3
supplementation for dry eye disease,” said Maryann
Redford, D.D.S., M.P.H., program officer for
clinical research at NEI.
Despite insufficient evidence establishing the
effectiveness of omega-3s, clinicians and their
patients have been inclined to try the supplements
for a variety of conditions with inflammatory
components, including dry eye.
“This well-controlled investigation conducted by the
independently-led Dry Eye Assessment and Management
(DREAM) Research Group shows that omega-3
supplements are no better than placebo for typical
patients who suffer from dry eye.”
The 27-center trial enrolled 535 participants with
at least a six-month history of moderate to severe
dry eye.
Among them, 349 people were randomly assigned to
receive 3 grams daily of fish-derived omega-3 fatty
acids in five capsules.
Each daily dose contained 2000 mg eicosapentaenoic
acid (EPA) and 1000 mg docosahexaenoic acid (DHA).
This dose of omega-3 is the highest ever tested for
treating dry eye disease.
The 186 people randomly assigned to the placebo
group received 5 grams daily of olive oil (about 1
teaspoon) in identical capsules.
Study participants and the researchers did not know
their group assignment.
Blood tests at 12 months confirmed that 85 percent
of people in the omega-3 group were still compliant
with the therapy.
In the omega-3 group, mean EPA levels quadrupled
versus no change in the placebo group.
Mean levels of oleic acid, the constituent of olive
oil, remained stable in both treatment groups.
Importantly, unlike in most industry-sponsored
trials, all participants were free to continue
taking their previous medications for dry eye, such
as artificial tears and prescription
anti-inflammatory eye drops.
“Omega-3s are generally used as an add-on therapy.
The study results are in the context of this
real-world experience of treating symptomatic dry
eye patients who request additional treatment,” said
study chair for the trial, Penny A. Asbell, M.D., of
the Department of Ophthalmology at the Icahn School
of Medicine at Mount Sinai in New York City.
Patient-reported symptoms were measured as change
from baseline in the Ocular Surface Disease Index, a
100-point scale for assessing dry eye symptoms, with
higher values representing greater severity.
After 12 months, mean symptoms scores for people in
both groups had improved substantially, but there
was no significant difference in the degree of
symptom improvement between the groups.
Symptom scores improved by a mean of 13.9 points in
the omega-3 group and 12.5 points in the placebo
group.
A reduction of at least 10 points on the index is
considered significant enough for a person to notice
improvement.
Overall, 61 percent of people in the omega-3 group
and 54 percent of those in the control group
achieved at least a 10-point improvement in their
symptom score, but the difference between the groups
was not statistically significant.
Likewise, there were no significant differences
between the groups in terms of improvement in signs
of dry eye.
Signs of dry eye were evaluated by the clinician
using standardized tests that measure the amount and
quality of tears and the integrity of the cornea and
the conjunctiva, the surface tissue that covers the
front of the eye.
“The findings also emphasize the difficulty in
judging whether a treatment really helps a
particular dry eye patient,” said the leader of the
coordinating center for the study, Maureen G.
Maguire, Ph.D., of the Department of Ophthalmology
at the Perelman School of Medicine at the University
of Pennsylvania, Philadelphia.
“More than half the people taking placebo reported
substantial symptom improvement during the year-long
study.”
“The results of the DREAM study do not support use
of omega-3 supplements for patients with moderate to
severe dry eye disease,“ Dr. Asbell concluded.
For more information
New England Journal of Medicine
n-3 Fatty Acid Supplementation for the Treatment of
Dry Eye Disease
Link...
U.S. National Eye Institute (NEI)
Link...
U.S. National Institutes of Health (NIH)
Link...
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