[Evaluation of acuity stereopsis in school children and teenagers with developmental dyslexia].

Introduction: The purpose of this study was to show to what extent developmental dyslexia influences a scope of stereoscopic.
Material and Methods: 176 pupils and students with developmental dyslexia were examined, including 52 girls and 124 boys aged between 8 and 19. Subjects were divided into three groups in respect of their age: I group 8-10 years, II group 10-14 years, III group 15-19 years of age, and in respect of a type of dyslexia into: visual and spatial type (W), language and auditory (S) and mixed (M). Long distance visual acuity in both eyes was 1.0 and near sight visual was 0.5 according to Snellen charts after correction of refraction error. Error of refraction ranged from +/- 0.5 Dsph to -2.25 Dsph and +3.0 Dsph, while astigmatism ranged from +/- 0.5 Dcyl to -2.0 Dcyl, +2.25 Dcyl. All the subjects had binocular vision in free space and on synoptophore (simultaneous perception, fusion, stereopsis). Reference group consisted of children and school children without ophthalmological pathological state. While analysing the obtained results it was found that the pupils and students with developmental dyslexia of group I and II and of dyslectic pathogenic groups (W, S, M) reached statistically considerably higher values of stereoscopic vision angle compared with analogous the control group. No significant differences were found between the age groups of pupils and students with dyslexia and dyslectic pathogenic groups and the control group within the scope of stereoscopic vision acuity and perception of Titmus test stereopsis threshold value of 40 arc sec.
Results: In dyslectic pathogenic groups (W, S, M) compared with the control group, the perception of Titmus test threshold value of 40 arc sec was observed significantly and statistically, less frequent.
Conclusions: In all pupils and students with developmental dyslexia value of stereopsis angle was statistically considerably higher, while the frequency of stereopsis threshold value perception for Titmus test was observed statistically considerably less often compared with values obtained in control group.