A 27-centre trial, involving 535 participants, has found that omega-3 fatty acid supplements taken orally proved no better than placebo at relieving symptoms or signs of dry eye.
Funded by the National Eye Institute (NEI), the trial findings were published in the New England Journal of Medicine.
Participants had at least a six-month history of moderate to severe dry eye. Among them, 349 people were randomly assigned to receive three 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 five grams daily of olive oil (about one teaspoon) in identical capsules. Study participants and the researchers did not know their group assignment.
Blood tests at 12 months confirmed 85 per cent of 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.
The study results are in the context of this real world experience of treating symptomatic dry eye patients who request additional treatment
All participants were free to continue taking their previous medications for dry eye, such as artificial tears and prescription antiinflammatory 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, Dr. Penny A. Asbell, Department of Ophthalmology, 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. After 12 months, symptom scores improved by a mean of 13.9 points in the omega-3 group and 12.5 points in the placebo group, but there was no significant difference in the degree of symptom improvement. Similarly, there were no significant differences in terms of improvement in signs of dry eye evaluated by the clinician.
“The results of the Dry Eye Assessment and Management (DREAM) study do not support use of omega-3 supplements for patients with moderate to severe dry eye disease,” Dr. Asbell concluded.