APP and Alzheimer disease: In murine models of AD that overexpress Aβ in the brain, studies have also found that Aβ is present in the retinae of a variety of strains such as the Tg2576 (Dutescu et al., 2009; Liu et al., 2009; Alexandrov et al., 2011), APP/PS1 (Ning et al., 2008; Perez et al., 2009; Alexandrov et al., 2011; Gupta et al., 2016), 3xTg (Alexandrov et al., 2011; Grimaldi et al., 2018) TgCRND8 (Buccarello et al., 2017) TgF344 (Tsai et al., 2014), and 5xFAD (Alexandrov et al., 2011).