Figure 3. Macitentan (5 mg/kg body wt) enhances retinal ganglion cells (RGCs) survival in rats during IOP elevation for 4 weeks. Representative images of Brn3a staining of RGCs in retinal flat mounts from rats that were either untreated or treated with macitentan, 3 days per week for 4 weeks following IOP elevation (A). Quantitation of Brn3a-positive RGCs in naïve eyes, untreated IOP-elevated eyes, and macitentan-treated IOP-elevated eyes of Brown Norway rats in the peripheral (B) and mid-peripheral (C) eccentricities, located at two-thirds and one-third of the width of the retina from the optic nerve head, respectively, and total RGC counts (D). Bars represent mean RGC count ± SEM * p<0.05, **p<0.005 indicates statistical significance, one-way ANOVA followed by Tukey’s multiple comparison test. Scale bar: 100 μm, n=7 (3 male rats and 4 female rats) for untreated rats, n=8 (4 male rats and 4 female rats) for macitentan-treated rats, and n=6 (3 male rats and 3 female rats) for naïve rats.