Figure 7. Retinal ganglion cell axon protection in wild-type and hypoxia-inducible factor-1α retinal ganglion cell-knockout mice with experimental glaucoma by prior repetitive hypoxic preconditioning. Quantification of SMI32-positive axons in the post-laminar optic nerve following 3 weeks of intraocular hypertension in the four experimental groups is shown, normalized to fellow eyes (black bars). Note that repetitive hypoxic preconditioning (RHP) provided protection against the glaucomatous loss of retinal ganglion cell (RGC) axons in the wild-type (WT; green) and hypoxia-inducible factor-1α retinal ganglion cell-knockout (HIF-1α RGC-KO; blue) mice. *p<0.05 versus fellow eye; #p<0.05 versus non-preconditioned glaucoma in the same genotype. Means±standard error of the mean (SEM).