title: Glare disability, photostress recovery, and chromatic contrast: relation to macular pigment and serum lutein and zeaxanthin.
abstract: OBJECTIVE
  A large body of research has linked macular lutein and zeaxanthin to reduced risk of degenerative eye disease. The earliest published hypothesis for the role of the pigments was not based on chronic protection but immediate function. Recent data on macular pigment (MP) have shown that screening the foveal cones from short-wave light does, in fact, result in improvements in photostress recovery (PR), glare disability (GD), and chromatic contrast (CC). This study examined those relations on a larger sample.
  
  
  METHODS
  A total of 150 young healthy subjects were assessed. Plasma samples were obtained from 100 subjects for HPLC quantification of serum xanthophylls. MP density was measured using customized heterochromatic flicker photometery. GD, PR, and CC were measured in Maxwellian view using a broadband xenon light source. GD was measured by increasing the intensity of an annulus until it veiled a central target. PR was measured as the time necessary to regain sight of a central target after a 5-second exposure to an intense bleaching light. CC was measured as the amount of light necessary in a 460-nm background to lose sight of a central target.
  
  
  RESULTS
  MP density was significantly related to serum lutein and zeaxanthin combined (r = 0.31, P = 0.002), GD (r = 0.24, P = 0.0015), PR (r = -0.18, P = 0.01), and CC (r = 0.46, P = 0.00005).
  
  
  CONCLUSIONS
  These results confirm earlier reports of a significant relation between variation in macular pigment optical density and immediate effects on visual function. As with many species, intraocular yellow filters in humans appear to improve many aspects of the visual stimulus. (ClinicalTrials.gov number, NCT00909090.).
authors.affiliation: Vision Sciences Laboratory, University of Georgia, Athens, Georgia 30602-3013, USA. bhammond@uga.edu
authors.forename: Billy R
authors.initials: BR
authors.lastname: Hammond
authors.forename: Laura M
authors.initials: LM
authors.lastname: Fletcher
authors.forename: James G
authors.initials: JG
authors.lastname: Elliott
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D019466:Glare; D006801:Humans; D014975:Lutein / Q000097:blood*; D008266:Macula Lutea / Q000502:physiology*; D008297:Male; D020127:Recovery of Function; D012016:Reference Values; D012168:Retinal Pigments / Q000502:physiology*; D014786:Vision Disorders / Q000378:metabolism / Q000503:physiopathology*; D024341:Xanthophylls / Q000097:blood*; D055815:Young Adult; D065146:Zeaxanthins
chemical_list: D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D014975:Lutein