title: The effect of contrast and luminance on mfERG responses in a monkey model of glaucoma.
abstract: OBJECTIVE
  To evaluate the effect of contrast and luminance attenuation on the multifocal electroretinogram (mfERG) responses of normal and glaucomatous eyes of cynomolgus monkeys.
  
  
  METHODS
  Nine adult male cynomolgus monkeys with unilateral experimentally induced glaucoma were used. Hypertension-induced damage was confirmed by tomography of the optic disc. mfERGs were recorded with five different stimulus contrasts and/or luminance settings. The first-order and the first slice of second-order responses were analyzed.
  
  
  RESULTS
  Waveforms of normal and glaucomatous eyes differed in shape and amplitude. Second-order responses contributed to first-order responses of the signals in the normal eyes, but made a negligible contribution to the signals in the glaucomatous eyes. Contrast and luminance attenuation affected both first- and second-order responses. The differences between signals in normal and glaucomatous eyes were sufficiently large for an unsupervised clustering algorithm to achieve accurate segregation.
  
  
  CONCLUSIONS
  The observations in this study indicate that outer and inner retinal generators participate in first-order mfERG responses and that both inner and outer retinal contributors respond to contrast and luminance changes in stimulus. The hypertension-induced changes in the mfERG furthermore suggest damage to both inner and outer retina.
authors.affiliation: Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel. razdo@agri.huji.ac.il
authors.forename: Dorit
authors.initials: D
authors.lastname: Raz
authors.forename: Mathias W
authors.initials: MW
authors.lastname: Seeliger
authors.forename: Amir B
authors.initials: AB
authors.lastname: Geva
authors.forename: Christine L
authors.initials: CL
authors.lastname: Percicot
authors.forename: George N
authors.initials: GN
authors.lastname: Lambrou
authors.forename: Ron
authors.initials: R
authors.lastname: Ofri
mesh_terms: D000818:Animals; D015350:Contrast Sensitivity / Q000502:physiology*; D004195:Disease Models, Animal; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005901:Glaucoma / Q000503:physiopathology*; D008027:Light; D008252:Macaca fascicularis; D008297:Male; D012160:Retina / Q000502:physiology*