title: Assessment of Visual and Chromatic Functions in a Rodent Model of Retinal Degeneration.
abstract: OBJECTIVE
  We evaluated the photoreceptor response of pigmented P23H and normal pigmented Long Evans (LE) rats over time using functional tests in variable lighting conditions.
  
  
  METHODS
  Pigmented P23H rats were studied by optomotor testing and electroretinogram (ERG) recordings at P30, P150, and P240. Pigmented LE rats were used as a normal wild-type control. Stimuli were modified with colored filters. Neutral density filters were used to reduce luminance.
  
  
  RESULTS
  Age-related decreases in visual acuity (VA) and contrast sensitivity (CS) were observed in P23H rats. Good correlations in measurements without filter and with green filter were observed between LE and P23H P30 rat values. Differences between groups were smaller with red and purple filters. A strong relationship with luminance was observed in LE rats (VA and CS) and with P23H P30 rats (CS). A decline in the ERG responses of P23H rats was consistent with the gradual loss of photoreceptors. Differences in a- and b-wave amplitudes with different colored filters were negligible with the exception of the red filter, which resulted in smaller responses.
  
  
  CONCLUSIONS
  Visual function parameters decreased with age in pigmented P23H rats. Irrespective of luminance, color filter, and retinal degeneration, minimum thresholds of VA and CS were found. Smaller differences than expected were found using color filters. Responses to functional tests at long wavelengths were observed, where there is very low photoreceptor spectral sensitivity. The use of filters with functional testing could minimize light-induced retinal damage in rats.
authors.affiliation: Department of Surgery, Gynecology and Obstetrics, University of Zaragoza, Zaragoza, Spain 2Aragon Institute for Health Research (IIS Aragón), Aragón, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Segura
authors.affiliation: Aragon Institute for Health Research (IIS Aragón), Aragón, Spain 3Department of Applied Physics, University of Zaragoza, Zaragoza, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Sánchez-Cano
authors.affiliation: Department of Applied Physics, University of Zaragoza, Zaragoza, Spain.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Jarabo
authors.affiliation: Aragon Institute for Health Research (IIS Aragón), Aragón, Spain 3Department of Applied Physics, University of Zaragoza, Zaragoza, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: López de la Fuente
authors.affiliation: Laboratory of the Neurobiology of the Visual System, Department of Physiology Genetics and Microbiology, University of Alicante, Alicante, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Cuenca
authors.affiliation: Department of Ophthalmology, University of Murcia, Murcia, Spain.
authors.forename: María P
authors.initials: MP
authors.lastname: Villegas-Pérez
authors.affiliation: Department of Surgery, Gynecology and Obstetrics, University of Zaragoza, Zaragoza, Spain 2Aragon Institute for Health Research (IIS Aragón), Aragón, Spain 6Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Pinilla
mesh_terms: D000818:Animals; D055253:Color Vision; D004195:Disease Models, Animal; D004596:Electroretinography; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D055647:Rats, Transgenic; D012162:Retinal Degeneration / Q000503:physiopathology*; D014792:Visual Acuity