Foveal contrast processing of increment and decrement targets is equivalently reduced in glaucoma

Abstract

Background: Psychophysical measurement of the function of individual precortical visual pathways (magnocellular, parvocellular and koniocellular) has enabled the development of sensitive tests for glaucoma and has enhanced understanding of its pathophysiology. Such pathways can be further subdivided into their "On" and "Off" components, which have anatomical and physiological asymmetries. This study investigated whether On and Off subdivisions of the magnocellular (M) pathway are differentially affected by glaucoma. Methods: 20 participants with glaucoma and 20 controls underwent two psychophysical procedures that have been shown to assess the M pathway (steady pedestal task) and its On and ..