title: Age-related Eye Disease Study 2: perspectives, recommendations, and unanswered questions.
abstract: OBJECTIVE
  This review provides a perspective on the Age-related Eye Disease Study 2 (AREDS2) including a summary of the goals and rationale of the study, major findings, subsequent management recommendations, and questions that remain to be answered.
  
  
  RESULTS
  The primary goal of the AREDS2 was to evaluate the efficacy and safety of lutein plus zeaxanthin and/or omega-3 long-chain polyunsaturated acid supplementation in reducing the risk of developing advanced age-related macular degeneration (AMD). AREDS2 also investigated the effects of omitting β-carotene and reducing the concentration of zinc from the original AREDS formulation. Although primary analysis from the AREDS2 did not reveal a benefit of daily supplementation with lutein/zeaxanthin on AMD progression, secondary exploratory analyses suggested that lutein/zeaxanthin were helpful in reducing this risk. Comparison of low-dose to higher-dose zinc showed no significant benefit.
  
  
  CONCLUSIONS
  The overall evidence on the beneficial and adverse effects from AREDS2 and other studies suggests that lutein/zeaxanthin could be more appropriate than β-carotene in AREDS-type supplements. Questions remain regarding the AREDS2 study results such as: whether the findings are generalizable to the population as a whole, what is the long-term safety profile of lutein/zeaxanthin supplementation, should other carotenoids be included in AREDS-type supplements, and at what optimal doses?
authors.affiliation: Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Aronow
authors.forename: Emily Y
authors.initials: EY
authors.lastname: Chew
mesh_terms: D019587:Dietary Supplements; D018450:Disease Progression; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D004359:Drug Therapy, Combination; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D006801:Humans; D014975:Lutein / Q000008:administration & dosage*; D008268:Macular Degeneration / Q000175:diagnosis / Q000517:prevention & control*; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D024341:Xanthophylls / Q000008:administration & dosage*; D065146:Zeaxanthins; D017967:Zinc Compounds / Q000008:administration & dosage
chemical_list: D015525:Fatty Acids, Omega-3; D024341:Xanthophylls; D065146:Zeaxanthins; D017967:Zinc Compounds; D004281:Docosahexaenoic Acids; D014975:Lutein