Abstract
Purpose: :
The idea that yellow intra-ocular pigments could improve vision through optical mechanisms has been postulated for over a century. The yellow macular pigments (MP), for instance, could improve vision by absorbing scattered light (e.g., glare) and by increasing contrast across chromatic borders.
Methods: :
111 young (mean age = 22 yrs) healthy subjects were assessed. MP density, glare disability (GD), photostress recovery time (PSR) and contrast enhancement (CE) were all measured psychophysically. GD was measured by varying the energy of a broad-band, 12° annulus in order to veil a 1° central long-wave grating target. PSR was determined by timing visual recovery (reacquiring sight of a shuttered 1° circular grating target) following an intense 3-second broad-band bleach. CE was determined by measuring increment thresholds to a 1° long-wave target presented on a 10°, 460 nm circular background.
Results: :
MP density was significantly correlated with GD (p < 0.01), PSR (p < 0.01) and CE (p < 0.0001).
Conclusions: :
These cross-sectional data (serum data will also be presented), showing a significant relation between MP and GD, PSR, and CE, are the baseline for a year-long clinical trial, now in progress, testing whether supplementing lutein and zeaxanthin leads to improved visual performance.
Clinical Trial: :
www.clinicaltrials.gov NCT00909090
Keywords: macular pigment • carotenoids/carotenoid binding proteins • retina