Glaucoma and the brain.

Abstract

The pathobiologic features of retinal ganglion cell death in glaucoma have been studied extensively at the level of the retina and optic nerve head. Retinal ganglion cell (RGC) axons form the optic nerve, chiasm, and optic tract and convey visual information to multiple nuclei in the brain. Most RGCs terminate in the lateral geniculate nucleus (LGN), the major vision center relaying information from the eye to the visual cortex. In each LGN, the complete contralateral hemifield of vision is represented, and parallel central visual pathways are segregated into anatomically distinct magnocellular, parvocellular, and koniocellular channels. The axons of relay LGN neurons form the optic radiations projecting to eye specific columns in the primary visual cortex. Recent investigations show evidence of extension of glaucomatous injury to these central visual stations and may offer additional insights into the nature of glaucomatous damage and vision loss.