Еvaluation of Stereo Vision Based on Chromostereopsis in Patients with Strabismus

The study is devoted to one of actual problems of modern strabismological — the development of effective methods for evaluation of stereo vision. The purpose: to develop an effective method for evaluating stereopsis based on chromostereopsis (CS) in patients with strabismus. Patients and methods. We observed 135 children aged from 8 to 17 years, who were divided into three groups, equivalent age: 1) 45 children with ametropia; 2) 31 children with not paralytic strabismus; 3) 59 children — the control group without ophthalmopathology. At the first stage, we investigated the possibility of using “ChromaDepth glasses” for qualitative assessment of stereo vision in three groups of children. We used three types of stimuli: a modified Kanisza shape; test images that create an illusory square shape; a color version of the Poggendorff shape. At the second stage, we investigated the possibility of using images with different spectral characteristics and prisms for qualitative and quantitative evaluation of stereovision based on CS in the same three groups of children. Results. The analysis of the results obtained at the first stage showed high sensitivity (90.6 % for the 1st stimulus, 90.5 % for the 2nd and 99 % for the 3rd) and specificity (96.5 % for the 1st stimulus, 93.3 % for the 2nd and 84.4 % for the 3rd) for all three stimuli used for qualitative evaluation of stereo vision. At the second stage, we obtained results demonstrating an increase in the severity of CS with an increase in the strength of prisms in control children and children with ametropia, as well as results indicating the effectiveness of the developed method for evaluating stereovision in children with a strabismus angle. Conclusion. The method of studying CS with the help of “ChromaDepth glasses” is a simple and effective method of qualitative assessment of stereovision. The developed method of qualitative and quantitative assessment of stereovision based on CS using stimuli with different spectral characteristics and prisms allows us to assess effectively the state of stereovision. It doesn’t required additional separation of the visual fields even if there is a strabismus angle (using its prismatic compensation) and predict the possibility of occurrence and severity of undesirable chromatic illusions in patients when prescribing prismatic correction.