Do omega-3 fatty acid supplements reduce CVS-related dry eye symptoms? Study finds

Australia: A systematic review and meta-analysis showed low certainty evidence of use of oral omega-3 fatty acid supplements for a reduction in computer vision syndrome (CVS)-related dry eye symptoms compared to placebo. The study article was published in Ophthalmology.

CVS is the leading occupational hazard of the 21st century affecting nearly about 70 percent of all computer users. The eye muscles are unable to recover from the constant tension required to focus on a computer for a protracted, uninterrupted, and prolonged time leading to CVS. It often exacerbates dry eye symptoms, such as eye strain and blurred vision, as well as other symptoms, such as headache. This set of issues related to CVS has inspired many prospective treatments, including widely marketed products like blue-light-blocking lenses and oral supplements.

Sumeer Singh, the University of Melbourne, Australia, and his team conducted a review to identify, appraise and synthesize clinical evidence related to the efficacy and safety of interventions for treating CVS, and thereby provide support to practitioners in providing evidence-based advice to their patients.

The study assessed evidence of CVS therapies from randomized controlled trials (RCTs) identified in Ovid MEDLINE, EMBASE, CENTRAL, and trial registries. The review included 45 RCTs representing about 4,500 patients.

Key findings of the study,

• 10 trials of optical aids such as multifocal contact lenses and blue-light-blocking glasses showed no effect on visual fatigue symptoms with low certainty of the evidence.

• Low certainty evidence was found for no difference between the use of oral berry extract and polyunsaturated fatty acid supplements.

• Based on two studies with high heterogeneity, there was low certainty evidence for a decrease in dry eye symptoms with omega-3 supplements compared to placebo.

• Oral carotenoid supplementation improved critical flicker-fusion frequency (CFF) relative to placebo, although the clinical significance of this finding is unclear.

• Fewer studies with comparable, quantitative outcomes were available for interventions, such as ergonomic adjustment and measures like the "20-20-20 rule" for taking breaks from screens.

Researchers conclude that only oral omega-3 supplements present evidence as a potentially effective treatment for CVS. Moreover, the possible benefit, the mechanism of therapeutic action and the frequency of adverse gastrointestinal effects of these supplements need to be studied before recommending them as therapy for CVS in the general population. There was insufficient evidence to establish efficacy or safety with certainty for other interventions.

The authors wrote that though CVS treatments are increasingly studied, the current quality of evidence is inadequate and recommend future studies after addressing the shortcomings in the design and reporting of RCTs investigating CVS treatments.

Reference:

Sumeer Singh, Myra B. McGuinness, Andrew J. Anderson, Laura E. Downie, Interventions for the management of computer vision syndrome: a systematic review and meta-analysis, Ophthalmology, 2022,  https://doi.org/10.1016/j.ophtha.2022.05.009.