Damage to the central nervous system (CNS) is always followed by an irreversible axon degeneration of injured neurons. Since the axonal regeneration is very difficult, many kinds of attempts have been made to enhance neuronal survival and axonal regeneration of axotomized neurons. Optic nerve and retina are derivatives of CNS, optic nerve is composed of axonal of retinal ganglion cells (RGCs). Many regeneration studies have been carried out using the retina and optic nerve as a model system, because the som...