Evaluating Visual Acuity and Contrast Sensitivity in Rats

Assessment of visual function was performed using an OptoMotry system (OptoMotry™, CerebralMechanics, Lethbridge, AB, Canada) [23 (link)]. This system was used to evaluate the visual acuity (VA) and contrast sensitivity (CS) of both P23HxLE and wild-type rats monthly from postnatal day 30 (P30) to P180. The maximum VA and minimum contrast identified were reached when the rat could not distinguish the stimuli presented and were judged by the experimenter using a video camera, which provides real-time feedback on a computer. VA and CS results depend on the experience and training of the experimenter, and thus all the rat-tracking movements were assessed by the same researcher.