To investigate the surgical outcomes of augmented bilateral medial rectus (BMR) recession in patients with low accommodative convergence/accommodation (AC/A) ratio tonic convergence excess esotropia (ET) compared to high AC/A ratio convergence excess ET.

This study included patients with esodeviation ≥10 prism diopter at near than at distance fixation who underwent BMR recession. The medical records of all esotropic patients with convergence excess who underwent strabismus surgery were reviewed. Six patients with tonic convergence excess and 10 patients with a high AC/A ratio met the study inclusion criteria. A successful outcome was defined as a near or distance angle of deviation ≤8 prism diopter and a ≤10 prism diopter difference between the two at the final recorded visit.

The mean age at surgery was 5.9 ± 1.6 years in the tonic convergence excess ET group and 7.3 ± 2.9 years in the high AC/A ET group ( p = 0.301). The average length of the postoperative follow-up was 2.7 years (range, 0.6–8.4 years) in the tonic convergence excess ET group and 4.0 years (range, 0.6–8.4 years) in the high AC/A ET group ( p = 0.426). Near-distance disparities were reduced in all patients with tonic convergence excess ET within 10 prism diopter postoperatively, but in only 6 of 10 patients in the high AC/A ET group. Five of 6 patients (83.3%) had successful outcomes in tonic convergence excess ET group; 5 of 10 patients (50%) had successful outcomes in the high AC/A ET group.

In our series, five patients (83%) obtained successful results in the tonic convergence excess ET group compared with 50% in the high AC/A ET group. Augmented BMR recession can be safely performed in esotropic patients with tonic convergence excess.