Abstract
Purpose: :
Macular pigment (MP), as a powerful antioxidant, and short wavelength optical filter, which is anatomically concentrated at the macula, may theoretically contribute to visual performance by attenuating the effects of chromatic aberration and light scatter, or by optimizing retinal health. This study was designed to assess whether macular pigment optical density (MPOD) is associated with visual performance.
Methods: :
142 young (mean age ± SD = 29 ± 6 years) healthy subjects were recruited into two separate study sites: Waterford Institute of Technology (WIT) and Dublin Institute of Technology (DIT). The spatial profile of MPOD (i.e. at 0.5, 0.25, 1, 1.75 and 3 degrees of retinal eccentricity) was assessed by customized heterochromatic flicker photometry. Visual performance was assessed psychophysically including quantification of best corrected visual acuity (BCVA), mesopic and photopic contrast sensitivity, glare sensitivity, photostress recovery time (PRT) and visual function by self-report.
Results: :
Mean ± SD peak MPOD (at 0.25°) was 0.48 ± 0.19. There was a positive and statistically significant relationship between BCVA and MPOD across its full spatial profile (r = 0.237 to 0.308, p < 0.01). MPOD was also positively and significantly related to both mesopic and photopic contrast sensitivity (at 7.5 cpd and 11.8 cpd), but this relationship was confined to the central MPOD at 0.25° and 0.50° of retinal eccentricity (r = 0.167 to 0.220, p < 0.05, for all). PRT, glare sensitivity, and self-reported visual function were unrelated to MPOD across its spatial profile.
Conclusions: :
Measures of central visual function, including visual acuity and contrast sensitivity, are positively associated with MPOD. A longitudinal, placebo-controlled and randomized supplementation trial will be required to ascertain whether augmentation of MP can influence visual performance or experience.
Clinical Trial: :
www.ISRCTN.org 35481392
Keywords: macular pigment • visual acuity • contrast sensitivity