Age–related study of the retinal function and morphology in Senescence Accelerated Mouse (SAM)

Abstract

Abstract: : Purpose: To investigate retinal function and morphology in a mouse model for aging, the senescence–accelerated mouse prone 8 (SAM P8). Methods: SAM P8 mice, in comparison to SAM resistant 1 (SAM R1) control animals, were studied by scotopic and photopic electroretinography (ERG) using previously reported protocols. Fundus images were obtained with a confocal SLO (Heidelberg Retina Angiograph, Heidelberg Engineering). The integrity of the vascular system was investigated by means of fluoresceine and indocyanine green (ICG) angiography. In addition, ultrastructural changes were assessed by microscopy. Results: Retinal function in the SAM P8 mice was similar to that in SAM R1 at 2 and 5 months of age. However, in 1 year–old animals, the scotopic and photopic b–wave amplitude was reduced in SAM P8 compared to SAM R1 mice (160 µV and 240 µV for the scotopic b–wave at 10000 cds/m² for SAM P8 and R1, respectively). No difference in fundus morphology was observed in SAM P8 and SAM R1 mice at any age. Moreover, the retinal and the choroidal vascular system were normal. Conclusions: The Senescence Accelerated Mouse SAM P8 develops a reduction in retinal function following 12 months of age without obvious specific morphological damage including the retinal and choroidal vasculature. It may be a useful model to study the influence of aging and thus deserves further detailed analysis.

Keywords: electroretinography: non–clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • aging