Statokinetic dissociation in lesions of the anterior visual pathways. A reappraisal of the Riddoch phenomenon
A. B. Safran and J. S. Glaser
With standard Goldmann perimetry, physiologic dissociation of kinetic and
statis stimuli was first investigated in 15 normal subjects. Variable
degrees of statokinetic dissociation (SKD) occurred for white and for red
(achromatic perception) targets, but not for chromatic recognition of red.
To analyze relative sensitivity of these stimuli in defining field defects,
a set of "isopter equivalents," eg, white I2e, red II4c (achromatic
perception), and red V4e (chromatic recognition) was empirically
established in normal and in pathologic fields of 11 patients with
compression of the anterior visual pathways. The "Riddoch phenomenon" (SKD)
was documented in defective fields in all patients with tumors; SKD
occurred for white or for red achromatic perception. The most sensitive
technique for elaborating field defects proved to be static presentation of
white or red stimuli (achromatic perception) and chromatic recognition of
static or kinetic red. As a rapid, sensitive screening method, especially
for subtle defects, we suggest the addition of chromatic recognition of
kinetic red stimuli to the application of standard kinetic white stimuli.
Our findings are discussed in light of current concepts of retinal ganglion
cell physiology.
