Binocular Interaction in Visual-Evoked Responses: Summation, Facilitation and Inhibition in a Clinical Study of Binocular Vision

Abstract

Binocular visual-evoked responses (VER) were recorded in normal and strabismic subjects. The percent increase of binocular with respect to monocular response was correlated to the degree of binocular performance expressed by the values of stereopsis in the Titmus stereo test and TNO test. Summation, facilitation and inhibition of binocular responses were found. In no case was a clear relationship found between the degree of binocularity and the amplitude of binocular VER. This limits clinical application of binocular VER recordings in the diagnosis of binocular vision disturbances.

Binocular summation in visual evoked cortical potential in patients who have significantly different P100 peak latencies in their two eyes

“…The results of earlier studies showed that binocular summation of VEPs in adults is less than that in infants [5,9,13,16]. In addition, the peak latency with binocular stimulation is shorter than that from monocular stimulation [1,2,8,11].…”

“…In addition, the peak latency with binocular stimulation is shorter than that from monocular stimulation [1,2,8,11]. It has been suggested that binocular enhancement is related to the presence of stereopsis [3,9,10,13,16], but other studies have found no relationship between binocular enhancement and stereopsis [5,14].…”

“…The electrophysiological studies have used visual evoked cortical potentials (VEPs) to assess the interaction of the signals [1,2,3,5,8,9,10,11,13,14,15,16], and one of the main aims of these studies has been to obtain a measure of binocular interaction objectively. Infants, children, patients with strabismus, and patients with poor binocular vision have been investigated.…”

“…In these studies, the amplitudes [1,2,3,5,9,10,13,14,15,16] and the implicit times [1,2,8,11,14] of the P100 component of the VEPs were studied, and the binocular interactions were determined by comparing VEPs elicited by monocular and binocular stimulation. In general, the differences in the peak latencies of the P100 component elicited by monocular stimulation of the two eyes were small, and as far as we know, no authors have examined binocular summation in cases with large interocular differences of the peak latencies.…”

Visual evoked potentials during suppression in exotropic and esotropic strabismics: strabismic suppression objectified

“…Wright studied the primary visual cortex and used pattern VEPs in esotropes. Other studies showed normal or summated VEPs [2,14]. They found no clear relationship between the degree of binocularity and the amplitude of binocular VEP.…”