Central Retinal Enrichment Supplementation Trials (CREST): Design and Methodology of the CREST Randomized Controlled Trials

• Published in: Ophthalmic epidemiology Vol. 21; no. 2; pp. 111 - 123
• Main Authors: Akuffo, Kwadwo Owusu, Beatty, Stephen, Stack, Jim, Dennison, Jessica, O'Regan, Sarah, Meagher, Katherine A., Peto, Tunde, Nolan, John
• Format: Journal Article
• Language: English
• Published: New York, NY Informa Healthcare USA, Inc 01.04.2014; Taylor & Francis; Informa Healthcare
• Subjects: Adult; Age-related macular degeneration; Aged; Biological and medical sciences; Contrast Sensitivity - drug effects; Dietary Supplements; Double-Blind Method; Drug Combinations; Female; Follow-Up Studies; Glare; Healthy Volunteers; Humans; lutein; Lutein - administration & dosage; Macular Degeneration - prevention & control; macular pigment; Male; Medical sciences; meso-zeaxanthin; Miscellaneous; Ophthalmology; Original; Pharmaceutical Preparations; Photometry; randomized clinical trial; Research Design; Retinal Pigments; Retinopathies; Sickness Impact Profile; Surveys and Questionnaires; Tomography, Optical Coherence; Visual Acuity - physiology; visual performance; Vitamins - administration & dosage; Xanthophylls - administration & dosage; zeaxanthin; Zeaxanthins; Retinopathy; Methodology; Xanthophyll; macular pigment; Retina; randomized clinical trial; meso-zeaxanthin; lutein; Design; Macula; Zeaxanthin; Eye disease; Visual performance; Age-related macular degeneration; Pigments; Clinical trial; Age related macular degeneration; Supplementation; Carotenoid
• ISSN: 0928-6586; 1744-5086; 1744-5086
• DOI: 10.3109/09286586.2014.888085

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.