title: Assessment of retinal degeneration in outbred albino mice.
abstract: Evaluation of a pharmaceutical's safety includes assessment of the potential for ophthalmologic toxicity. These nonclinical studies commonly use various outbred stocks of mice. Pretest indirect ophthalmoscopic examinations in the commonly used outbred stock Hsd:ICR(CD-1) indicated that retinal degeneration was a problem in this particular outbred stock of mice. This prompted the authors to examine other stocks of outbred mice routinely used in the performance of nonclinical safety studies. Groups of mice were observed over a 13-week period to determine the progression and changing incidence of retinal degeneration. Light intensity in the room and caging was measured during the study, and it was determined that light did not play a direct role in the progression of the retinal degeneration observed during the study. Histomorphologic examination of the mouse eyes was performed at the end of the study to confirm the presence of retinal degeneration observed after ophthalmoscopic examination. The incidence of retinal atrophy in the various outbred stocks of mice was: Crl:CFW(SW)BR (98.3%), Tac(SW)fBR (80%), Tac:Icr:Ha(ICR)fBR (75%), Hsd:ICR(CD-1) (43.3%), and Crl:CF-1BR (3.0%). Retinal atrophy was not observed in the following outbred mice stocks: Crl:CD-1(ICR)BR, HsdWin:CFW1, and Hsd:NSA(CF-1). On the basis of these findings, it is highly recommended that pretest ophthalmologic screening be performed on mice to obviate pre-existing conditions from confounding or invalidating nonclinical study results.
authors.affiliation: Calvert Laboratories, Inc., Scott Technology Park, 100 Discovery Drive, Olyphant, Pennsylvania 18447, USA.
authors.forename: Laurie M
authors.initials: LM
authors.lastname: Serfilippi
authors.forename: Danielle R Stackhouse
authors.initials: DR
authors.lastname: Pallman
authors.forename: Margarita M
authors.initials: MM
authors.lastname: Gruebbel
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Kern
authors.forename: Charles B
authors.initials: CB
authors.lastname: Spainhour
mesh_terms: D000818:Animals; D021461:Animals, Outbred Strains; D005123:Eye / Q000473:pathology; D005260:Female; D015994:Incidence; D008297:Male; D051379:Mice; D009887:Ophthalmoscopy / Q000662:veterinary; D012162:Retinal Degeneration / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D012376:Rodent Diseases / Q000453:epidemiology / Q000473:pathology*; D013045:Species Specificity; D014481:United States / Q000453:epidemiology