HDAC3 and glaucoma: Silencing of normal gene expression has been noted as an early change associated with retinal ganglion cell (RGC) death in experimental models of glaucoma and other optic nerve diseases, and an evaluation of apoptotic RGCs in mice showed that histone deacetylase 3 (HDAC3) and histone H4 deacetylation may be critical mediators of gene silencing [23].