Purpose

To describe the relationship between binocular summation and stereoacuity after strabismus surgery.

Design

Prospective case series.

Methods

setting: Stein Eye Institute, University of California Los Angeles.

Patient population

Pediatric strabismic patients who underwent strabismus surgery between 2010 and 2015.

Observation procedures

Early Treatment Diabetic Retinopathy Study visual acuity, Sloan low-contrast acuity (LCA, 2.5% and 1.25%), and Randot stereoacuity 2 months following surgical correction of strabismus.

Main outcome measures

The relationship between binocular summation (BiS), calculated as the difference between the binocular visual acuity score and that of the better eye, and stereoacuity.

Results

A total of 130 postoperative strabismic patients were studied. The relationship between binocular summation and stereoacuity was studied by Spearman correlation. There were significant correlations between BiS for 2.5% LCA with near and distance stereoacuity (P = .006 and P = .009). BiS for 1.25% LCA was also significantly correlated with near stereoacuity (P = .04). Near stereoacuity and BiS for 2.5% and 1.25% LCA were significantly dependent (Pearson χ(2), P = .006 and P = .026). Patients with stereoacuity demonstrated significantly more BiS in 2.5% LCA of 2.7 (P = .022) and 3.1 (P = .014) letters than did those without near or distance stereoacuity, respectively.

Conclusions

These findings demonstrate that stereopsis and binocular summation are significantly correlated in patients who have undergone surgical correction of strabismus.