Evaluation of Sensory Dominance Using Binocular Rivalry as Related to Ocular Deviations

Abstract

Introduction and Purpose To investigate the relationship between sensory dominance and ocular deviations. Patients and Methods Sixty-three patients were evaluated with a new device for the measurement of exclusive visibility during binocular rivalry. The patients were consisted of twenty-three with exotropia (XT), twenty with intermittent exotropia [X(T)], twenty with exophoria (XP), respectively. Device is composed of two retinometers, their holders in which angle and position can be adjustable and a PC for data storage and analysis. In each of eyes, exclusive visibility of one stimulus during binocular rivalry was measured for 60 sec, and the strength of ocular dominance was evaluated by the difference of exclusive visibility between dominant and nondominant eye. Results The difference of exclusive visibility time between dominant and nondominant eye were 9.8 ± 3.7 sec in the XT group, 6.1 ± 4.1 sec in the X(T) group and 2.2 ±1.5 sec in the XP group, respectively. There were significant differences between XT and X(T) (P < 0.01) as well as between XT and XP (P < 0.001). Conclusions The present result indicates that sensory dominance was obviously influenced by ocular deviations since exclusive visibility of dominant eye was prolonged with decreasing the opportunity of normal binocular vision such as XT or X(T).