title: The attenuation of blue-on-yellow perimetry by the macular pigment.
abstract: OBJECTIVE
  To determine the influence of macular pigment absorption on blue-on-yellow perimetry using a technique suitable for application with the Humphrey Field Analyzer.
  
  
  METHODS
  The sample comprised one eye from each of 46 healthy subjects (age range, 20-80 years). Macular pigment absorption was assessed by measuring medium-wavelength sensitive cone sensitivity for 460- and 570-nm narrowband stimuli at the fovea, at 5.5 degrees and at 8 degrees eccentricity. The differences in sensitivities recorded between the fovea and 8 degrees eccentricity and between 5.5 degrees and 8 degrees eccentricity for the 460-nm stimulus relative to a value of zero at 570 nm were attributed to absorption by the macular pigment. Blue-on-yellow perimetry was undertaken using a 460-nm narrowband blue Goldmann size V stimulus and a yellow 330-cdm-2 background.
  
  
  RESULTS
  Group macular pigment absorption (mean +/- standard error) was 0.40 +/- 0.03 log units foveally and 0.00 +/- 0.03 log units at 5.5 degrees eccentricity. The group mean foveal macular pigment absorption was significantly different from zero (P < 0.01). The coefficient of repeatability for the macular pigment absorption procedure (based on test-retest data for 16 subjects) was +/- 0.28 log units at the fovea and +/- 0.35 log units at 5.5 degrees eccentricity.
  
  
  CONCLUSIONS
  The net effect of ocular media and macular pigment absorption relative to 460 nm was to attenuate the blue-on-yellow visual field at the fovea by approximately 0.80 log units and elsewhere by 0.40 log units.
authors.affiliation: Department of Vision Sciences, Aston University, Birmingham, United Kingdom.
authors.forename: J M
authors.initials: JM
authors.lastname: Wild
authors.forename: C
authors.initials: C
authors.lastname: Hudson
mesh_terms: D000042:Absorption; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008266:Macula Lutea / Q000502:physiology*; D008875:Middle Aged; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012168:Retinal Pigments / Q000502:physiology*; D012684:Sensory Thresholds; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*
chemical_list: D012168:Retinal Pigments