title: A technique for in vivo measurement of photoreceptor orientation in the chicken retina.
abstract: The aim of the current study was to develop a method for simultaneously assessing central and peripheral photoreceptor alignment in vivo in animal models. The stimulus apparatus consisted of nine light-emitting diodes (LED) positioned 7.5 degrees apart around an arc. The stimulus was viewed through a pinhole imaged into the entrance pupil of the eye using a telecentric lens system. Photodiodes placed over an array of the VERIS imaging system stimulated the electroretinogram. Data were obtained by positioning the pinhole at 0.25-mm intervals across the pupil and recording (Volk Optical, Mentor, OH, USA) at each location. Orientation assessed in normal chickens demonstrates that photoreceptors orientate towards a locus near the centre of the pupil and that there is a systematic change in peak location with eccentricity. This technique provides a valuable method for determining photoreceptor orientation properties in vivo and can be applied to animal models of pathology.
authors.affiliation: School of Optometry, University of New South Wales, Sydney, Australia. j.beresford@unsw.edu.au
authors.forename: J A
authors.initials: JA
authors.lastname: Beresford
authors.forename: S G
authors.initials: SG
authors.lastname: Crewther
authors.forename: D P
authors.initials: DP
authors.lastname: Crewther
mesh_terms: D000818:Animals; D002645:Chickens; D004596:Electroretinography; D008722:Methods; D008954:Models, Biological; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D011680:Pupil / Q000502:physiology; D012016:Reference Values; D012160:Retina / Q000502:physiology*