A technique for in vivo measurement of photoreceptor orientation in the chicken retina

Aust N Z J Ophthalmol. 1999 Jun-Aug;27(3-4):241-3. doi: 10.1046/j.1440-1606.1999.00180.x.

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.

MeSH terms

  • Animals
  • Chickens
  • Electroretinography
  • Methods
  • Models, Biological
  • Photoreceptor Cells, Vertebrate / physiology*
  • Pupil / physiology
  • Reference Values
  • Retina / physiology*