In late-stage glaucoma patients, the ONH astrocytes are activated and characterized by morphologic changes (enlarged soma and thicker cellular processes in the prelaminar region, and round-shape cell body and loss of processes in the LC) and increased GFAP expression (Varela and Hernandez, 1997; Hernandez et al., 2000; Wang et al., 2002). This evidence concerns the gene GFAP and glaucoma.