Nitric-oxide synthase and neurodegeneration/neuroprotection.

Abstract

Glaucoma is an optic neuropathy in which the retinal ganglion cells and their axons, which package and transmit visual impulses from the photoreceptors and associated retinal interneurons to the brain, die individually or in small groups, typically over many years (Figs. 1 and 2) (1). The resulting functional deficit is the second leading cause of irreversible visual loss in the U.S., and the most common cause among African-Americans. In its most prevalent form, the condition is strongly dependent upon age, race, and family history. Approximately 3–5% of White Americans, 10% of African-Americans, and 20% of Afro-Caribbeans over the age of 70 years have the disease (2–5). As lifespan and the proportion of the population comprising the aged increase, so will the number and proportion afflicted.