title: Lower Macular Pigment Optical Density in Foveal-Involved Glaucoma.
abstract: OBJECTIVE
  To evaluate the relationship between macular pigment optical density (MPOD) and structural parameters of the macula and optic nerve head in glaucomatous eyes.
  
  
  METHODS
  A cross-sectional analysis of the baseline data collected during the Macular Pigment and Glaucoma Trial (ISRCTN registry number: 56985060).
  
  
  METHODS
  Eighty-eight subjects (48 male, 40 female) with a diagnosis of open-angle glaucoma and a median age of 67 years (interquartile range, 13; range, 36-84 years) were enrolled in this trial.
  
  
  METHODS
  The MPOD at 0.25°, 0.5°, and 1° retinal eccentricity was measured using a customized heterochromatic flicker photometry technique. Glaucoma-related structural parameters were captured using RTVue Fourier-domain optical coherence tomography (FD-OCT). Statistical significance was set at P < 0.01, and P values ranging from 0.01 to 0.05 were considered borderline significant.
  
  
  METHODS
  The MPOD and its relationship to the macula and optic nerve head topography in glaucomatous eyes.
  
  
  RESULTS
  The MPOD peaked centrally at 0.25° of retinal eccentricity (mean ± standard deviation, 0.23±0.14) and decreased at more peripheral eccentricities. For the overall group, borderline significant correlations were observed between MPOD and a range of topographic measures, including inferior peripapillary retinal nerve fiber layer (RNFL) thickness, inferior ganglion cell complex (GCC) thickness, foveal inner retinal thickness, cup-to-disc area ratio, and optic disc rim area. Glaucomatous eyes with GCC loss involving the foveal zone on FD-OCT imaging (n = 52) had lower MPOD at 0.25°, 0.5°, and 1° of retinal eccentricity compared with those without foveal GCC involvement (P < 0.001, for all). Those with foveal GCC loss also had greater glaucoma severity, and this was evident by lower GCC and RNFL thickness, greater cup-to-disc area ratio, and lower optic disc rim area (P < 0.001 for all).
  
  
  CONCLUSIONS
  Our observations indicate that MPOD is lower in glaucomatous eyes with foveal GCC involvement relative to those without foveal involvement. A longitudinal evaluation of MPOD and structural change among patients with glaucoma is required to elucidate the nature of any causal relationship that might exist between MPOD and foveal damage in glaucoma.
authors.affiliation: Institute of Ophthalmology, Mater Misericordiae University Hospital, Eccles Street, Dublin, Ireland. Electronic address: wefong_siah@yahoo.com.
authors.forename: We Fong
authors.initials: WF
authors.lastname: Siah
authors.affiliation: Optometry Department, School of Physics, College of Sciences and Health, Dublin Institute of Technology, Dublin, Ireland; Faculty of Health Sciences, African Vision Research Institute, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: James
authors.initials: J
authors.lastname: Loughman
authors.affiliation: Institute of Ophthalmology, Mater Misericordiae University Hospital, Eccles Street, Dublin, Ireland.
authors.forename: Colm
authors.initials: C
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003720:Densitometry; D004311:Double-Blind Method; D005247:Feeding Behavior; D005260:Female; D005583:Fourier Analysis; D005584:Fovea Centralis; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D014975:Lutein / Q000378:metabolism*; D008266:Macula Lutea / Q000378:metabolism* / Q000473:pathology; D065348:Macular Pigment / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology; D010783:Photometry / Q000379:methods; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014792:Visual Acuity / Q000502:physiology; D065146:Zeaxanthins / Q000378:metabolism*
chemical_list: D065348:Macular Pigment; D065146:Zeaxanthins; C584722:meso-zeaxanthin; D014975:Lutein