Short-Term Near Stereoacuity Improvements Following Favorable Surgical Alignment in Exotropic and Esotropic Patients

Purpose Surgical treatment for strabismus is to promote binocular vision, and the study is to evaluate the effect of surgical realignment on near stereopsis in exotropic and esotropic patients. Methods The records of patients who underwent strabismus surgery were retrospectively reviewed. Visual acuity, ocular deviations, fusion control, ocular motility, strabismus subtype and duration, surgery procedures, and stereopsis at before and at one month after surgery were collected. RMANOVA was performed to analyze stereopsis improvement by surgery. A logistic analysis was used to investigate the factors for stereopsis improvement. Results 143 exotropic and 40 esotropic patients were enrolled. The stereopsis was not significantly improved in patients with exotropia (p > .05), but not in esotropic patients (p < .01). Small degree of near deviation (beta = 0.01), without vertical surgery (beta = 0.11), and the high pre-surgery Titmus (beta = -0.44) were related factors for stereopsis improvement in exotropia patients; male (beta = 0.21) and the high pre-surgery Titmus (beta = -0.36) were related factors for stereopsis improvement in esotropia patients. Conclusion The loss of stereopsis was significantly restored by surgery in esotropia patients and the extent of stereopsis recovery by surgery depends on the deviation at near distance, vertical surgery, and pre-surgery stereopsis in exotropes and on sex and pre-surgery Titmus in esotropes.