Results of Using Different Modes of Presentation of Stereostimuli in the Study of Stereo Vision in Normal Children and in Children with Non-Paralytic Strabismus without Functional Scotoma

Abstract

The work is devoted to one of the actual problems of current ophthalmology — creating effective methods of studying stereovision.The purpose — comparative analysis of the capability of stereoperception under conditions of using different regimes of alternating presentation of stereo stimuli with different characteristics in children with strabismus and in children without ophthalmopathology.Patients and methods. 294 school children — 167 children of the control group (without ophthalmopathology) and 127 children with non-paralytic strabismus without functional scotoma (FSS) were observed. We used stereostimuli with different characteristics in the following regimes of presentation: 1) the regime of simple monocular alternating (alternate presentation of an image for the right and left eye); 2) the regime having an “empty” interval (black background) between monocular phases; 3) the regime having a binocular phase (a binocular image containing details corresponding to the stimuli for the right eye and the left eye) between monocular phases.Results. It was found that the majority of children with non-paralytic strabismus, who are incapable of stereoperception with the classic Fly-test and Lang-test, can perceive the stereoeffect with alternating presentation of stereostimuli within individual ranges of durations of monocular phases, a binocular phase and an “empty” interval. In children of the control group when switching from the simple alternation regime to the “empty” interval regime the maximal durations of monocular phases, which preserved the stereoeffect, decreased and when switching to the binocular phase regime they significantly increased. In children with strabismus linear images are simpler for stereoperception than random-dot images as well as in children of the control group (p < 0.001); stimuli creating the effect of the frontoparallel separation of details get perceived better than those creating the decline effect or the turning effect (p < 0.001); stimuli creating the effect of the vertical stripes decline get perceived better than those creating the effect of the horizontal stripes turning (p < 0.001). However, as opposed to the children of the control group, in children with strabismus the stereoeffect gets formed better under conditions of the peripheral localization of linear details than under conditions of the central one.Conclusion. Using computer programs with different regimes of alternating presentation of stereostimuli with certain characteristics allows to effectively evaluate individual capability of stereoperception which is necessary for the personalized approach to the selection of visual stimuli and stimuli presentation regimes in functional treatment of patients with non-paralytic strabismus.