title: Selective photoreceptor damage in albino rats using continuous blue light. A protocol useful for retinal degeneration and transplantation research.
abstract: OBJECTIVE
  To develop a retinal degeneration model with selective photoreceptor loss and RPE sparing, to be used as recipient for evaluating retinal transplants.
  
  
  METHODS
  Albino rats were exposed to blue light, continuously, for 1-7 days (24-168 h) in a specially designed cage. Eyes were histologically analyzed at periods between 2 h and 8 months after the light exposure. Electroretinograms (ERGs) were recorded from some rats at 12-216 days after exposure. Using behavioral methods, visual thresholds of some rats were determined before exposure and re-measured between 18 and 52 days following exposure.
  
  
  RESULTS
  Apoptotic nuclei appeared exclusively in the photoreceptor layer after 1-5 days exposure to blue light. Light microscopy revealed that 2-4 days of light exposure reduced the outer nuclear layer (normally eight to ten rows) to 1 row of cells in the central retina and to two to three rows in the periphery, both in the superior and the inferior retina. Average ERG a- and b-wave amplitudes of light-damaged rats were both reduced by about 98%. Visual performance in the behavioral test was substantially impaired.
  
  
  CONCLUSIONS
  Continuous exposure of albino rats to moderate blue light for 2-5 days selectively eliminates most of the photoreceptors while leaving the RPE initially intact.
authors.affiliation: Department of Ophthalmology & Visual Sciences, University of Louisville, KY 40202, USA. mjseil@athena.louisville.edu
authors.forename: M J
authors.initials: MJ
authors.lastname: Seiler
authors.forename: O L
authors.initials: OL
authors.lastname: Liu
authors.forename: N G
authors.initials: NG
authors.lastname: Cooper
authors.forename: T L
authors.initials: TL
authors.lastname: Callahan
authors.forename: H M
authors.initials: HM
authors.lastname: Petry
authors.forename: R B
authors.initials: RB
authors.lastname: Aramant
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D004596:Electroretinography; D005260:Female; D006085:Graft Survival / Q000528:radiation effects; D020287:In Situ Nick-End Labeling; D008027:Light / Q000009:adverse effects*; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology / Q000528:radiation effects*; D010857:Pigment Epithelium of Eye / Q000528:radiation effects / Q000637:transplantation; D011833:Radiation Injuries, Experimental / Q000209:etiology* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012162:Retinal Degeneration / Q000209:etiology* / Q000473:pathology; D013997:Time Factors