Central Retinal Enrichment Supplementation Trials (CREST): design and methodology of the CREST randomized controlled trials. Design and methodology of the crest randomized controlled trials

Kwadwo Owusu Akuffo, Stephen Beatty, Jim Stack, Jessica Dennison, Sarah O'Regan, Katherine A. Meagher, Tunde Peto, John Nolan

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)

Abstract

PURPOSE:The Central Retinal Enrichment Supplementation Trials (CREST) aim to investigate the potential impact of macular pigment (MP) enrichment, following supplementation with a formulation containing 10 mg lutein (L), 2 mg zeaxanthin (Z) and 10 mg meso-zeaxanthin (MZ), on visual function in normal subjects (Trial 1) and in subjects with early age-related macular degeneration (AMD; Trial 2). METHODS:CREST is a single center, double-blind, randomized clinical trial. Trial 1 (12-month follow-up) subjects are randomly assigned to a formulation containing 10 mg L, 10 mg MZ and 2 mg Z (n = 60) or placebo (n = 60). Trial 2 (24-month follow-up) subjects are randomly assigned to a formulation containing 10 mg L, 10 mg MZ, 2 mg Z plus 500 mg vitamin C, 400 IU vitamin E, 25 mg zinc and 2 mg copper (Intervention A; n = 75) or 10 mg L and 2 mg Z plus 500 mg vitamin C, 400 IU vitamin E, 25 mg zinc and 2 mg copper (Intervention B; n = 75). Contrast sensitivity (CS) at 6 cycles per degree represents the primary outcome measure in each trial. Secondary outcomes include: CS at other spatial frequencies, MP, best-corrected visual acuity, glare disability, photostress recovery, light scatter, cognitive function, foveal architecture, serum carotenoid concentrations, and subjective visual function. For Trial 2, AMD morphology, reading speed and reading acuity are also being recorded. CONCLUSIONS:CREST is the first study to investigate the impact of supplementation with all three macular carotenoids in the context of a large, double-blind, randomized clinical trial.
Original languageEnglish
Pages (from-to)111-23
Number of pages13
JournalOphthalmic Epidemiology
Volume21
Issue number2
DOIs
Publication statusPublished - Apr 2014

Keywords

  • Age-related macular degeneration
  • Lutein
  • Macular pigment
  • meso-zeaxanthin
  • Randomized clinical trial
  • Visual performance
  • Zeaxanthin

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