title: Stiles-Crawford effect in focal macular ERGs from macaque monkey.
abstract: BACKGROUND
  To determine whether the focal macular electroretinograms (FMERGs) are affected by the angle of incidence of the stimulating light on the retina, i.e., the Stiles-Crawford effect (SCE).
  
  
  METHODS
  FMERGs were elicited by focal stimulation of the macula in three light-adapted macaque monkeys. The incidence of the light on the retina was varied from 0 to ±11.7°. The effects of the incidence and wavelengths of the stimulus on the SCE were determined.
  
  
  RESULTS
  The amplitudes of the FMERG components were largest when the stimulus beam entered the eye on the visual axis and passed through the center of the pupil. The amplitudes gradually decreased as the stimulus beam passed through the pupil more eccentrically and fell on the retina more obliquely. All components of the FMERGs were decreased with the decrease least for the amplitude of the d-wave.
  
  
  CONCLUSIONS
  The decrease in the amplitudes of the FMERGs as the angle of incidence of the stimulus beam on the retina increases demonstrates that the SCE can be detected in adult macaque monkeys. This objective method of assessing the SCE suggests that this technique can be used to assess the alignment of cones in humans with different types of macular diseases.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Oita University, Oita,  Japan.
authors.forename: Celso Soiti
authors.initials: CS
authors.lastname: Matsumoto
authors.forename: Kei
authors.initials: K
authors.lastname: Shinoda
authors.forename: Harue
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Satofuka
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizota
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakatsuka
authors.forename: Yozo
authors.initials: Y
authors.lastname: Miyake
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000818:Animals; D004596:Electroretinography / Q000379:methods*; D006801:Humans; D008029:Lighting; D008251:Macaca; D008266:Macula Lutea / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D010775:Photic Stimulation / Q000379:methods*; D011680:Pupil / Q000502:physiology; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*