New horizons in neuroprotection.

Glaucoma is a leading cause of blindness worldwide and the second leading cause of irreversible blindness in the USA. The most common form of glaucoma, primary open angle glaucoma, is characterized by a chronically elevated intraocular pressure in the absence of any demonstrable structural abnormalities in the eye. The pathologic hallmark of glaucomatous optic neuropathy is the selective death of retinal ganglion cells associated with structural changes in the optic nerve head. Recent discoveries suggest a role for nitric oxide, glutamate, apoptosis, and others, in the pathophysiology of this neuropathy. These newer discoveries are addressed in this article.