The thesis presents solving the urgent problem of modern ophthalmology concerning the increase in accuracy of determining the pathology of extraocular muscles in strabismus by developing a method for assessing their anatomical and functional condition with the help of interference patterns observed in the cornea in polarized light. The idea of polarization-optical properties of the cornea in extraocular muscle pathology was further developed. According to the results of studyingthe parameters of 167 interference patterns in patients with convergent strabismus, we found out that there was an imbalance of horizontal musclesin (73±3,4)% of cases, as evidenced by the angles between the diagonal segments of the interference rhombus, which average (90±5.0)0, and the ratio of the lengths of the diagonal segments, which did not exceed 1.1-1.2. There was a displacement of the upper rectus muscle in the medial direction in (27±3.4)% of cases as evidenced by the displacement of the upper angle of the interference rhombus in the medial direction, as well as the values of the angles between the diagonal segments of the interference rhombus were (80±5.5)0 (р<0,05) and (100±6.7)0 (р<0,05). In 100% of divergent strabismus cases, the interference patterns showed a displacement of the upper angle of the interference rhombus in the lateral direction, accompanied by an increase in the medial angle between the diagonal segments and a decrease in the lateral angle relative to the upper quadrant actions. The angles of the upper quadrant of the interference rhombus differed by an average of 320 (р<0,05) in (51±7.3)% of cases, and the degree of displacement of the upper rectus muscle in the lateral direction differed by 150 (р<0,05) in (49±7.3)% of cases. Analysis of the shape of the interference patterns of healthy individuals showed signs of asymmetry in (72±6.1)% of cases, indicating anatomical and functional asymmetry of the rectus extraocular muscles, which did not lead to obvious strabismus (р<0,05). We were the firstto determine that increased effort from the inner, upper and lower rectus muscles led to increased stress in the entire central zone of the cornea, which was limited by isochromic first order, with significant asymmetry of the calculated isochromia was not observed. This finding was possible due to analysis of the distribution of internal stresses in the cornea using the finite element model of the cornea. Increasing the force on the part of the external rectus muscle also did not increase the asymmetry of the calculated isochromia, nor it changed the distribution of internal stresses in the central zone of the cornea. The analysis of informative parameters of isochromes (ratio of diagonal segments and values of angles between them) showed that the approximation of the muscular force to the limbus from the normal position along the line of action, as well as its removal along the line of action caused not only segments of the corresponding diagonal (р<0.05), but also the displacement of the angles of the isochrome from the corresponding meridians in the range from 10 to 50 (р<0.05). Ruptures of the upper angle of the isochrome were observed when the place of application of the upper rectus muscle from the normal position towards the equator (р<0.05). In order to use all possible changes in the shape of interference patterns in strabismus, we proposed to determine angles between segments of interference rhombus diagonals and corresponding meridians of the eye in addition to segments of interference rhombus diagonals, which allowed considering all options of shift of a place of applying the efforts of direct extraocular muscles from a line of action. We improved models for classification of interference patterns of eyes with horizontal strabismus, which allowed determining the state of extraocular muscles in automatic mode by a two-stage algorithm. On the first stage there was a distribution of parameters of interference patterns into clusters by values of all angles between segments of diagonals of interference rhombus. On the second stage, the distribution of parameters of interference patterns happened by the values of the lengths of the segments of its diagonals. The use of the developed models allowed assigning the interference pictures of patients with horizontal strabismus to the appropriate cluster without errors, which helped us to determine the cause of eye deviation and increased the accuracy of determining the violation of the rectus extraocular muscles. The mathematical model for diagnosing strabismus was developed for the first time. It contains blocks for obtaining images of interference patterns and their parameterization, a database that stores information about the subject in the form of records with the date of examination, combined with a picture of interference pattern of the cornea. The image of the interference pattern after parameterization and determination of informative parameters is classified using the developed models to the appropriate cluster, which allows determining the existing pathology of the extraocular muscles.
