Взаимоотношения монокулярного и бинокулярного механизмов пространственного восприятия до и после функционального лечения у детей с послеоперационной остаточной микродевиацией

Abstract

Purpose. Of this work is to study the relationship of monocular and binocular mechanisms of spatial perception before and after functional treatment in children with postoperative residual microdeviation. Material and methods. The study included 30 children aged 8 to 16 years (average 12.5 years) with postoperative residual microdeviation (RM) and 44 children of the same age (average 10.6 years) in the control group. Along with the usual ophthalmic examination, Bagolini test, Lang test and Fly test were used to evaluate binocular functions in all children. To study the stereokinetic effect (SE), a ring image with a diameter of 20 cm with an eccentricity (the ratio of the displacement of the central element of the ring image from the center of rotation to the radius of the image) of 0.4 rotating on a laptop screen at the speed of 60 rpm was presented using a computer program developed by M.V. Zhmurov was used. The distance from the eyes to the image was 3 m. A child was asked to evaluate the illusory size of the virtual cone or the virtual funnel in binocular and monocular viewing conditions. Seven reference paper cones with a base diameter of 20 cm and a height of 5.10, 15, 20, 25, 30 and 35 cm were used to facilitate estimates of the SE value. The child pointed the paper cone closest in size to the virtual cone or virtual funnel. We also noted the time of dominance of the virtual cone and the virtual funnel during their alternation (in seconds per 1 min) and then calculated the average time of domination of both variants of the virtual figure. The study of visual functions and SE in children with RM was carried out before and after the course of functional treatment, providing presenting of stereostimules in the alternation mode using a computer program developed by M.V. Zhmurov. Three modes of alternative presentation of stimuli were used: 1) with consecutive monocular presentation of visual stimuli corresponding to the right and left eye; 2) with the presence of an empty interval between monocular phases; 3) with the presence of a binocular phase between monocular phases. Results. In all children with RM, the results of the stereovision study with Lang-test, Fly-test were negative before treatment. After functional treatment, 24 children showed stable binocular character of vision, the results of the study with Fly-test after treatment were positive in 20 children, and in five children with Lang-test. Orthotropy was achieved in 24 children. As a result of treatment, the visual acuity of the amblyopic eye increased from 0.74±0.03 to 0.91±0.01. The number of children with RM perceiving SE in the form of alternating virtual figures (cone and funnel) increases from 50% to 83.3% as a result of treatment. The dominance time of the virtual cone in children with RM significantly decreased (p<0.01) after treatment both in monocular conditions (average from 2.9±0.2 to 2.3±0.1 s) and in binocular conditions (average from 3.6 ±0.2 to 3±0.1 s), reaching the values of the control group. As a result of treatment of children with RM, the average size of the virtual cone for binocular conditions decreased from 21.3±1.2 to 16.8±0.9 cm and was significantly lower (p<0.001) compared with both the mean values before treatment and with the average values in the control group. After treatment, the average value of the virtual funnel for binocular conditions decreased from 19±1.1 cm to 13.1±0.7 cm and was significantly lower compared with the values obtained before treatment (p<0.001) and in the control group (p<0.05). Conclusion. Using alternating presentation of stereoimages in functional treatment of children with RM leads to positive changes: a reduction or elimination of residual deviation, improved visual acuity of amblyopic eye, increasing of the number of patients with stable bifoveal fusion and appearance of a stereo vision in them. The number of children with RM perceiving SE in the form of alternating virtual figures (cone and funnel) increases as a result of treatment. The dominance time of the virtual cone in children with RM significantly decreases after treatment, reaching the values in the control group. The average value of the virtual cone size for binocular conditions in children with RM significantly decreases after treatment to values smaller than in the control group, and for monocular observation conditions – increases to values comparable with the results in the control group. The average value of the virtual funnel size for binocular conditions in children with RM significantly decreases after treatment in comparison both with the values obtained before treatment and with the values obtained in the control group. Changes in the relationship between monocular and binocular mechanisms of spatial perception can serve as additional criteria for assessing the effectiveness of functional treatment of patients with RM.