title: Fast assessment of the central macular pigment density with natural pupil using the macular pigment reflectometer.
abstract: We built a new macular pigment reflectometer (MPR) for fast and objective measuring of the optical density of macular pigment in the human eye, using the undilated eye. The design is based on the spectral reflectance from a spot of white light at the fovea. To evaluate its performance, we measured the macular pigment of 20 healthy subjects, ages 18 to 79 years, under four conditions: (1) natural pupil in the dark, (2) natural pupil with dim room light, (3) dilated pupil in the dark, and for comparison with a different technique, (4) heterochromatic flicker photometry (HFP) in dim room light with natural pupil. Condition 1 was repeated in a subset of 10 subjects after an interval of at least 3 days. Data analysis with a model of reflectors and absorbers in the eye provided the density of the macular pigment in conditions 1 to 3. Dim room light and pupil dilatation had no influence on measured density. Mean within subjects variation was typically 7%. Mean difference between test and retest after at least 3 days was 1%. Correlation between MPR and HFP was r=0.56 (p=0.012). Mean within subjects variation with HFP was 19%. The new instrument holds promise for specific applications such as epidemiological research.
authors.affiliation: University Medical Center Utrecht, Department of Ophthalmology, AZU E03.136, P.O. Box 85500, NL-3508 GA Utrecht, The Netherlands. jkraats@umcutrecht.nl
authors.forename: Jan
authors.initials: J
authors.lastname: van de Kraats
authors.forename: Tos T J M
authors.initials: TT
authors.lastname: Berendschot
authors.forename: Suze
authors.initials: S
authors.lastname: Valen
authors.forename: Dirk
authors.initials: D
authors.lastname: van Norren
mesh_terms: D003199:Computer Systems; D003720:Densitometry / Q000295:instrumentation*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008266:Macula Lutea / Q000737:chemistry*; D010783:Photometry / Q000295:instrumentation* / Q000379:methods; D011680:Pupil / Q000502:physiology; D015203:Reproducibility of Results; D012168:Retinal Pigments / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D012168:Retinal Pigments