title: A central dip in the macular pigment spatial profile is associated with age and smoking.
abstract: OBJECTIVE
  To investigate the relationship between specific macular pigment (MP) spatial profiles and risk factors for age-related macular degeneration (AMD).
  
  
  METHODS
  The MP spatial profile of 484 healthy subjects was measured with customized heterochromatic flicker photometry (cHFP) and categorized into one of two profile types: typical exponential or atypical "central dip." Data on risk factors for AMD were obtained with a general health and lifestyle questionnaire. Dietary and serum concentrations of lutein (L) and zeaxanthin (Z) were also assessed.
  
  
  RESULTS
  The presence of the central dip MP spatial profile was significantly more common in older subjects (the mean ± SD age of subjects with a central dip MP spatial profile was 46.9 ± 12 years, whereas the mean age of subjects with a typical MP spatial profile was 41.8 ± 12 years; P = 0.004) and in current cigarette smokers (P = 0.031). Also, there was a significant age-related decline in central MP optical density (MPOD; 0.25° retinal eccentricity), but in the men only (r = -0.146, P = 0.049).
  
  
  CONCLUSIONS
  A central dip in the MP spatial profile, seen in older subjects and in cigarette smokers, may represent an undesirable feature of macular pigmentation. Further research is needed in this area.
authors.affiliation: Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Kirby
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
authors.forename: Edward
authors.initials: E
authors.lastname: Loane
authors.forename: Mukunda C
authors.initials: MC
authors.lastname: Akkali
authors.forename: Eithne E
authors.initials: EE
authors.lastname: Connolly
authors.forename: Jim
authors.initials: J
authors.lastname: Stack
authors.forename: John M
authors.initials: JM
authors.lastname: Nolan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000428:Alcohol Drinking; D002851:Chromatography, High Pressure Liquid; D005127:Eye Color / Q000502:physiology; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D014975:Lutein / Q000378:metabolism*; D008266:Macula Lutea / Q000378:metabolism*; D008268:Macular Degeneration / Q000209:etiology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010783:Photometry / Q000295:instrumentation; D012168:Retinal Pigments / Q000378:metabolism*; D012307:Risk Factors; D012907:Smoking / Q000378:metabolism*; D011795:Surveys and Questionnaires; D024341:Xanthophylls / Q000378:metabolism*; D055815:Young Adult; D065146:Zeaxanthins
chemical_list: D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D014975:Lutein