Potential role of nitric oxide and endothelin in the pathogenesis of glaucoma

Glaucoma is an optic nerve head neuropathy in which retinal ganglion cells are lost. A clear association exists between glaucoma and different risk fa ctors, such as high intraocular pressure (IOP) or blood-flow dysregulation. Nitric oxide (NO) and endothelin, two recently identified cellular mediato rs, appear to be involved in the regulation of IOP as well as in the modula tion of ocular blood flow. To some extent, NO is also involved in apoptosis , a mechanism of cell death that can lead to retinal ganglion cell loss in glaucoma. This article provides a short and simplified overview of the bioc hemistry of NO and endothelin and highlights the potential role of these tw o mediators in certain important aspects related to the pathogenesis of gla ucoma. (C) 1999 by Elsevier Science Inc. All rights reserved.