title: REPRODUCIBILITY OF MACULAR PIGMENT OPTICAL DENSITY MEASUREMENT BY TWO-WAVELENGTH AUTOFLUORESCENCE IN A CLINICAL SETTING.
abstract: OBJECTIVE
  Macular pigment, composed of lutein, zeaxanthin, and meso-zeaxanthin, is postulated to protect against age-related macular degeneration, likely because of filtering blue light and its antioxidant properties. Macular pigment optical density (MPOD) is reported to be associated with macular function evaluated by visual acuity and multifocal electroretinogram. Given the importance of macular pigment, reliable and accurate measurement methods are important. The main purpose of this study is to determine the reproducibility of MPOD measurement by two-wavelength autofluorescence method using scanning laser ophthalmoscopy.
  
  
  METHODS
  Sixty-eight eyes of 39 persons were enrolled in the study, including 11 normal eyes, 16 eyes with wet age-related macular degeneration, 16 eyes with dry age-related macular degeneration, 11 eyes with macular edema due to diabetic mellitus, branch retinal vein occlusion or macular telangiectasia, and 14 eyes with tractional maculopathy, including vitreomacular traction, epiretinal membrane, or macular hole. MPOD was measured with a two-wavelength (488 and 514 nm) autofluorescence method with the Spectralis HRA + OCT after pupil dilation. The measurement was repeated for each eye 10 minutes later. The analysis of variance and Bland-Altman plot were used to assess the reproducibility between the two measurements.
  
  
  RESULTS
  The mean MPOD at eccentricities of 1° and 2° was 0.36 ± 0.17 (range: 0.04-0.69) and 0.15 ± 0.08 (range: -0.03 to 0.35) for the first measurement and 0.35 ± 0.17 (range: 0.02-0.68) and 0.15 ± 0.08 (range: -0.01 to 0.33) for the second measurement, respectively. The difference between the 2 measurements was not statistically significant, and the Bland-Altman plot showed 7.4% and 5.9% points outside the 95% limits of agreement, indicating an overall excellent reproducibility. Similarly, there is no significant difference between the first and second measurements of MPOD volume within eccentricities of 1°, 2°, and 6° radius, and the Bland-Altman plot showed 8.8%, 2.9%, and 4.4% points outside the 95% limits of agreement, respectively. The data for the reproducibility did not differ significantly among the various disease and normal eyes.
  
  
  CONCLUSIONS
  Under routine examination conditions with pupil dilation, MPOD measurement by two-wavelength autofluorescence method showed a high reproducibility.
authors.affiliation: *Jacobs Retina Center, Shiley Eye Institute, University of California San Diego, San Diego, California; and †Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Qi Sheng
authors.initials: QS
authors.lastname: You
authors.forename: Dirk-Uwe G
authors.initials: DU
authors.lastname: Bartsch
authors.forename: Mark
authors.initials: M
authors.lastname: Espina
authors.forename: Mostafa
authors.initials: M
authors.lastname: Alam
authors.forename: Natalia
authors.initials: N
authors.lastname: Camacho
authors.forename: Nadia
authors.initials: N
authors.lastname: Mendoza
authors.forename: William R
authors.initials: WR
authors.lastname: Freeman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003720:Densitometry; D003930:Diabetic Retinopathy / Q000378:metabolism*; D005260:Female; D006801:Humans; D014975:Lutein / Q000378:metabolism; D008268:Macular Degeneration / Q000378:metabolism*; D008269:Macular Edema / Q000378:metabolism*; D065348:Macular Pigment / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging; D015203:Reproducibility of Results; D065146:Zeaxanthins / Q000378:metabolism
chemical_list: D065348:Macular Pigment; D065146:Zeaxanthins; C584722:meso-zeaxanthin; D014975:Lutein