CCNA2 and glaucoma: Moreover, cellular senescence plays a critical role in the pathogenesis of glaucoma, and the p16 upregulation triggered by acute IOP elevation appears to be a cause of RGC death.3, 23 Our findings demonstrate that upregulation of TBK1 and p16 is associated with elevated IOP and that elimination of TBK1 diminishes p16 and cyclin A expression.