Identification of novel pharmacological targets to minimize excitotoxic retinal damage.

Excitotoxic neuronal death is a common feature of neurodegenerative and ischemic diseases of the central nervous system (CNS) and of a variety of ocular diseases, including glaucoma. Glaucoma, one of the leading causes of blindness in the world, is characterized by a progressive degeneration of retinal ganglion cells (RGCs) and their axons and is often associated with elevated intraocular pressure (IOP). Retinal ischemia/reperfusion induced by experimental elevation of IOP leads to damage and loss of RGCs. Under these conditions, structural, functional, and biochemical changes implicate the accumulation of extracellular glutamate and activation of the excitotoxic cascade. Beside the activation of associated pathways, death of RGCs is accompanied by impaired endogenous defenses, such as the PI3K/Akt prosurvival pathway. Original neurochemical and pharmacological evidence are discussed here to strengthen the role for excitotoxicity in RGCs death occurring in experimental, angle closure, glaucoma in conjunction with the discovery of novel molecular targets to potentiate endogenous prosurvival defenses in the glaucomatous retina.