Fish oil supplementation does not reduce the risk or severity of dry eye disease

Reference

Christen WG, Cook NR, Manson JE, et al, for the VITAL Research Group. Efficacy of marine omega-3 fatty acid supplementation vs placebo in reducing incidence of dry eye disease in healthy US adults. A randomized clinical trial. JAMA Ophthalmol 2022;140(7):707-714.

Synopsis

As part of a large nationwide randomized trial of vitamin D and marine omega-3 fatty acids (fish oil) in the primary prevention of cancer and cardiovascular disease, this prespecified ancillary study evaluated the potential for fish oil to prevent the development and/or reduce the severity of dry eye disease (DED). Study participants (mean age 67 years) who reported no previous diagnosis of DED and were not experiencing dry eye symptoms (N = 25,523) randomly received (concealed allocation assignment) 1 g fish oil (eicosapentaenoic acid and docosahexaenoic acid in a ratio of approximately 2.2:1) or matched placebo daily. Study participants, masked to treatment group assignment, self-assessed dry eye symptoms using a validated scoring questionnaire. Follow-up responses occurred for 93.2% of participants for a median range of 5.3 years. When possible, the diagnosis of DED was confirmed by a review of the medical records or via a treating clinician questionnaire. Using intention-to-treat analysis, no significant difference in the confirmed diagnosis of incidence DED occurred between the treatment and control groups (2.0% vs 2.0%, respectively). Similarly, no group differences occurred in the incident reporting of severe DED symptoms.