Session: Poster session C

Near and distance Stereoacuity Improvements Following Successful Surgical Alignment in Exotropic and Esotropic cases

Introduction: Surgical treatment for strabismus is to encourage binocular vision, and the study is to evaluate the effect of surgical realignment on near and distance stereopsis in exotropic and esotropic cases.

Methods: The records of patients who underwent strabismus surgery for esotropia and exotropia were retrospectively reviewed. Patients were included in the study if they achieved postoperative satisfactory alignment (< 10 PD). Visual acuity, ocular deviations, ocular motility, strabismus subtype and duration, surgery procedures, and stereopsis at before and at 1, 6, 12, 24, 48, 60 and 72 months after surgery were collected. Wilcoxon signed ranks test was performed to analyze stereopsis improvement by surgery. A logistic regression analysis was used to investigate the factors for stereopsis improvement.

Results: 22 exotropic and 46 esotropic patients were enrolled. After surgery, near stereopsis was improved in 56 patients (82.3%) including 45 (97.8%) esotropic patients and 11 (50%) exotropic patients. Distance stereopsis was improved in 53 patients (77.9%) including 40 (87.0 %) esotropic patients and 13 (59.1%) exotropic patients. The near and distance stereopsis after surgery was significantly improved in patients with esotropia (p <0.001, p<0.001), but not in exotropic patients (p =0.248, p=0.753). Spherical refraction and anisometropia were related factors for distance stereopsis improvement in esotropia patients (OR 1.802, p=0.028) (OR 4.670, p=0.029).

Conclusions: The loss of stereopsis was significantly restored by appropriate surgery in esotropia patients and the extent of distance stereopsis recovery by surgery depends on spherical refraction and anisometropia.