Factors Influencing Stereopsis Outcomes in Adults Following Strabismus Surgery.

Objectives: The aim of the study was to evaluate binocular vision after adult strabismus surgery and to investigate the predictive factors on improvement stereoacuity.

Methods: Patients aged upper from 16 years who underwent strabismus surgery in our hospital reviewed retrospectively. Age, existence of amblyopia, pre-operative and postoperatively fusion ability, stereoacuity, and deviation angle were recorded. Patients were divided into two groups according to final stereoacuity; 200 sn/arc and lower: Good stereopsis (Group 1), upper 200 sn/arc: Poor stereopsis (Group 2). Characteristics were compared between groups.

Results: A total of 49 patients, who were 16-56 years of age, were included in the study. The mean follow-up time was 37.8 months (range 12-72 months). Of patients, 26 had improvement in stereopsis scores after surgery (53.0%). Group 1 includes 200 sn/arc and lower (n=18, 36.7%) and Group 2 includes higher than 200 sn/arc (n=31, 63.3%). The presence of amblyopia and higher refraction error was frequent significantly in Group 2 (p=0.01 and p=0.02, respectively). The existence of fusion postoperatively was significantly frequent in Group 1 (p=0.02). Type of strabismus and the amount of deviation angle were not found in a relationship with good stereopsis.

Conclusion: In adults, surgical correction of horizontal deviation improves stereoacuity. Having no amblyopia, having fusion after surgery, and low refraction error are predictive for the improvement in stereoacuity.