Dark adaptation in glaucomatous and nonglaucomatous optic nerve atrophy

Optic nerve damage is associated with impairment of psychophysical functions. We measured dark adaptation in 21 eyes of 14 normal subjects, 35 eyes of 19 patients with primary open-angle glaucoma, and 7 eyes of 4 patients with nonglaucomatous descending optic nerve atrophy. In the normal subjects light thresholds and time of the shoulder in the dark adaptation curve increased significantly with age. In eyes with glaucomatous or nonglaucomatous optic nerve damage light sensitivity was lower than in normal eyes of age-matched control groups. Rod light sensitivity was significantly (P less than 0.05) correlated with neuroretinal rim loss, parapapillary chorioretinal atrophy, and relative afferent pupillary defects. We conclude that velocity and degree of dark adaptation decrease with increasing age. Patients with glaucomatous and nonglaucomatous optic nerve atrophy show decreased light sensitivity especially in the rod part of dark adaptation worsening with advancing optic nerve damage.