title: Macular pigment spatial distribution effects on glare disability.
abstract: OBJECTIVE
  This project explored the relationship of the macular pigment optical density (MPOD) spatial profile with measures of glare disability (GD) across the macula.
  
  
  METHODS
  A novel device was used to measure MPOD across the central 16° of retina along four radii using customized heterochromatic flicker photometry (cHFP)at eccentricities of 0°, 2°, 4°, 6° and 8°. MPOD was measured as discrete and integrated values at all measured retinal loci. GD was calculated as a difference in contrast sensitivity (CS) between no glare and glare conditions using identical stimuli presented at the same eccentricities. GD was defined as [(CSNo Glare-CSGlare)/CSNo Glare] in order to isolate the glare attenuation effects of MPOD by controlling for CS variability among the subject sample. Correlations of the discrete and integrated MPOD with GD were compared.
  
  
  RESULTS
  The cHFP identified reliable MPOD spatial distribution maps demonstrating a 1st-order exponential decay as a function of increasing eccentricity. There was a significant negative correlation between both measures of foveal MPOD and GD using 6 cycles per degree (cpd) and 9 cpd stimuli. Significant correlations were found between corresponding parafoveal MPOD measures and GD at 2 and 4° of eccentricity using 9 cpd stimuli with greater MPOD associated with less glare disability.
  
  
  CONCLUSIONS
  These results are consistent with the glare attenuation effects of MP at higher spatial frequencies and support the hypothesis that discrete and integrated measures of MPOD have similar correlations with glare attenuation effects across the macula. Additionally, peak foveal MPOD appears to influence GD across the macula.
authors.affiliation: University of Missouri, St Louis College of Optometry, United States. Electronic address: christopher.putnam@us.af.mil.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Putnam
authors.affiliation: University of Missouri, St Louis College of Optometry, United States.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Bassi
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D005584:Fovea Centralis; D019466:Glare; D006801:Humans; D008266:Macula Lutea / Q000502:physiology*; D065348:Macular Pigment / Q000378:metabolism*; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D065348:Macular Pigment
keywords: Densidad óptica del pigmento macular; Distribución espacial; Glare disability; Macular pigment optical density; Spatial distribution; Trastorno de refracción