title: Repeated measures of macular pigment optical density to test reproducibility of heterochromatic flicker photometry.
abstract: OBJECTIVE
  To report the reproducibility of macular pigment optical density (MPOD) values assessed with heterochromatic flicker photometry (HFP) in healthy individuals.
  
  
  METHODS
  Twenty-four volunteers from our department underwent MPOD testing of both eyes by flicker photometry on three separate occasions. To test reproducibility of MPOD, the coefficient of variance was calculated separately for right and left eyes. In addition, we investigated MPOD averages of right and left eyes and interocular correlations (Pearson's r) at every visit.
  
  
  RESULTS
  The mean MPODs at the first visit were 0.61 +/- 0.24 and 0.72 +/- 0.27 in right and left eyes, respectively. Mean values of 0.58 +/- 0.29 and 0.60 +/- 0.21 (second visit) and 0.62 +/- 0.27 and 0.63 +/- 0.24 (third visit) were assessed for right and left eyes, respectively. Differences of the mean values between eyes were not significant. Correlations were weak at visits one and two (r = 0.49, p < 0.014 and r = 0.43, p < 0.038, respectively) and moderate at visit three (r = 0.58, p < 0.003). The coefficients of variance were 36.1% and 23% for right and left eyes, respectively.
  
  
  CONCLUSIONS
  Our mean MPODs are higher and the interocular correlations weaker compared to the literature. The coefficient of variance in both eyes is high and does not imply good reproducibility of obtained MPOD values.
authors.affiliation: Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser Surgery, Rudolf Foundation Clinic, Vienna, Austria. hagen_stefan@yahoo.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Hagen
authors.forename: Ilse
authors.initials: I
authors.lastname: Krebs
authors.forename: Carl
authors.initials: C
authors.lastname: Glittenberg
authors.forename: Susanne
authors.initials: S
authors.lastname: Binder
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D014975:Lutein / Q000032:analysis*; D008297:Male; D010783:Photometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012160:Retina / Q000737:chemistry*; D012168:Retinal Pigments / Q000032:analysis*; D024341:Xanthophylls / Q000032:analysis*; D065146:Zeaxanthins
chemical_list: D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D014975:Lutein