GFAP and retinitis pigmentosa 1: Thus, a common feature of all retinal diseases, including RP, glaucoma, DR, and AMD in both animal models and humans, is the presence of a high level of GFAP in Müller cells (Madigan et al., 1994; Strettoi et al., 2002; Wang et al., 2002; Gerhardinger et al., 2005; Inman and Horner, 2007; Vogler et al., 2014; Hippert et al., 2015).