Abstract

Ganglion cells of the retina, whose axons comprise the optic nerve fibers, are lost in glaucoma. To help estimate the extent of ganglion cell loss in the clinic and to establish a diagnosis of glaucoma, measurement of the cup-to-disk ratio of the optic nerve head and psychophysical perimetry are used. These methods can only detect loss after it occurs, however, and up to 40% of the ganglion cells may be lost before visual field defects appear in perimetry¹.

© 1996 Optical Society of America