Supplementation with the carotenoids lutein or zeaxanthin improves human visual performance

• Published in: Ophthalmic & physiological optics Vol. 26; no. 4; pp. 362 - 371
• Main Authors: Kvansakul, Jessica, Rodriguez-Carmona, Marisa, Edgar, David F., Barker, Felix M., Köpcke, Wolfgang, Schalch, Wolfgang, Barbur, John L.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2006; Blackwell
• Subjects: aberrations; Adolescent; Adult; Biological and medical sciences; contrast acuity; Contrast Sensitivity - drug effects; Dietary Supplements; Eye and associated structures. Visual pathways and centers. Vision; Fovea Centralis - drug effects; Fundamental and applied biological sciences. Psychology; Humans; Light; lutein; Lutein - administration & dosage; Macula Lutea - drug effects; macular pigment; Male; Pigment Epithelium of Eye - drug effects; retinal carotenoids; scattered light; Scattering, Radiation; Space Perception - drug effects; Vertebrates: nervous system and sense organs; Visual Acuity - drug effects; Xanthophylls - administration & dosage; zeaxanthin; Zeaxanthins; Human; contrast acuity; scattered light; Xanthophyll; macular pigment; Retina; aberrations; retinal carotenoids; Contrast; lutein; Macula; Zeaxanthin; Visual performance; Light; Pigments; Ophthalmology; Supplementation; Carotenoid; Retinal
• ISSN: 0275-5408; 1475-1313
• DOI: 10.1111/j.1475-1313.2006.00387.x

Background:  Macular pigment (MP) is found in diurnal primate species when vision spans a range of ambient illumination and is mediated by cone and rod photoreceptors. The exact role of MP remains to be determined. In this study we investigate two new hypotheses for possible MP functions. Objective:  As MP absorption coincides partly with that of rhodopsin, MP may reduce rod signal effectiveness in the mesopic range, thus extend the usefulness of cone‐mediated vision into the mesopic range. Forward light scatter in the eye can reduce retinal image contrast. If blue light contributes significantly to intraocular scatter, selective blue light absorption by MP could reduce the effects of scatter. Design:  We investigated 34 subjects from a carotenoid supplementation trial. The measurements included high mesopic contrast acuity thresholds (CATs), macular pigment optical density (MPOD), wavefront aberrations, and scattered light. The measurements were made after 6 months of daily supplementation with zeaxanthin (Z, OPTISHARP™), lutein (L), a combination of the two (C), or placebo (P), and again after a further 6 months of doubled supplementation. Results:  The data reveal a trend toward lower CATs in all groups supplemented, with a statistically significant improvement in the lutein group (p = 0.001), although there was no correlation with MPOD. Light scattering in the eye and the root‐mean‐square wavefront aberrations show decreasing trends as a result of supplementation, but no correlation with MPOD. Conclusions:  The results suggest that supplementation with L or Z increases MPOD at the fovea and at 2.5°, and that supplementation can improve CATs at high mesopic levels and hence visual performance at low illumination.