Dataset Comparison of strabismus angle performed with synoptophore and prism cover test including the impact of convergence and BSV_12_2024_anonymized.xlsx

Abstract Purpose: The present study compared the angle of deviation performed with synoptophore and the prism cover test (PCT) in participants with manifest horizontal strabismus. A secondary aim was to establish whether there is a correlation between the near point of convergence and the angle of deviation and to analyze the relationship between binocular single vision and the size of the strabismus angle, as well as to explore how BSV varies with different types of strabismus. Methods: In a retrospective study, 108 participants with six different types of horizontal strabismus were identified. Participants with vertical deviations over 2 prism diopters (PD), nystagmus and amblyopia were excluded from the study. The angle of deviation was measured with the use of synoptophore and PCT at far. The correlation between the angle of deviation and the near point of convergence was evaluated. Results: Statistically significant differences were found (p<0.05) between synoptophore and PCT measurements indicating an overestimation of strabismus angle measured with synoptophore in esotropia and the underestimation in exotropia. In addition, correlation between strabismus measurements and convergence was found. Conclusion: The synoptophore and prism cover test are reliable methods for quantifying strabismus, still, the differences can be found between the two methods. Convergence appears to affect these measurements. The difference in measurements between synoptophore and PCT may be deemed clinically relevant and therefore an individual patient approach in the management of these conditions is recommended. Larger strabismus angles were associated with weakened or absent BSV, and its condition depended on the type of strabismus.