Topic: What is the evidence for efficacy of dietary and/or supplemental omega-3 fatty acids in preventing age-related macular degeneration (AMD)?
Clinical relevance: Age-related macular degeneraion is the leading cause of blindness and vision impairment in persons older than 50 years living in North America. There is no cure for AMD, and treatment does not usually restore vision but only prevents disease progression to a modest degree. omega-3 fatty acids are considered potentially important antioxidants and are being considered as an arm of the Age-Related Eye Disease Study II clinical trial.
Methods/literature reviewed: Keywords were searched in Medline, Pre-Medline, Embase, and the Cochrane Library on Ovid. There was no restriction on the year or language of publication.
Results: There were 6 observational studies found, but the specific outcomes, exposures, and covariates studied all varied greatly.
Conclusion: There is some clinical evidence for protection of AMD from omega-3 fatty acids. However, the results are not consistent. Hence, our conclusion is that this issue is neither clearly supported nor refuted by the present world literature. This is an intriguing and extremely important question but needs further study first with prospective cohort designs and, if positive, randomized clinical trials.