Psychophysical measurement of neural adaptation abnormalities magnocellular and parvocellular pathways in glaucoma

Abstract

PURPOSE. It is well established that contrast sensitivity is reduced in glaucoma. This study explored whether such contrast processing abnormalities consist of an absolute threshold level difference or a problem with contrast gain control. METHODS. Seventeen patients with primary open-angle glaucoma and 17 approximately age-matched control subjects participated. Subjects were tested foveally and midperipherally (12.5°). Subjects with glaucoma were tested in a peripheral region of relatively normal visual field (neighboring locations required to be within the normal 95% confidence limit on the total deviation plot of their most recent SITA/full threshold Humphrey Field Analyzer assessment; Ca..