The role of temporal threshold criteria in psychophysical testing in glaucoma

The magnicellular system seems to be affected early and specifically by glaucomatous damage. It shows high temporal resolution and good motion perception. Psychophysical tests investigating the temporal transfer characteristics of the afferent visual system thus are of special interest for the detection of early glaucomatous damage. Flicker perimetry is largely independent from disturbances of the ocular media and provides a means to identify eyes with pressure-produced functional loss. Defects in temporal modulation perimetry may precede the onset or progression of defects in conventional light-sense perimetry. Motion sensitivity seems to be affected early by glaucomatous damage. The problem of noisefield campimetry is the lack of quantification and reliability control of the patients' responses. Large-field or Ganzfeld stimulators can separate glaucomatous from normal eyes with high sensitivity and specificity; their value for the identification of eyes at risk to develop progression of functional loss still must be demonstrated.