The Long-Term Outcome of Lateral Rectus Advancement in Patients with Consecutive Esotropia Following Bilateral Lateral Rectus Recession for Intermittent Exotropia

ABSTRACT

PURPOSE: To investigate the long-term outcome of lateral rectus (LR) advancement for consecutive esotropia following bilateral LR recession for intermittent exotropia. METHODS: Medical records of 25 patients who underwent LR advancement for consecutive esotropia after bilateral LR recession and who were followed up for more than 24 months postoperatively were reviewed. Patients were divided into two groups: bilateral lateral rectus recession (BLR) group included 16 patients with consecutive esotropia greater than or the same magnitude as the initial exotropia and who underwent bilateral LR advancement; Unilateral lateral rectus recession (ULR) group included nine patients with consecutive esotropia less than the initial exotropia and who underwent unilateral LR advancement. Main outcome measurements were motor and sensory outcomes and the dose-effect relationship calculated from observed overall and group changes in the angle of deviation per millimeter. Motor success was defined as alignment from orthotropia to exodeviation less than 10 PD at distance. Sensory outcome was described by comparing the Titmus stereoacuity test before and after LR advancement. Sensory successvwas defined at 100 seconds of arc. RESULTS: Eighteen patients (72.0%) showed satisfactory long-term motor and sensory outcomes. Seventeen (77.3%) of 22 patients showed favorable stereopsis of 100 seconds of arc or more at final observation. The long-term motor success rate of the ULR group was better than that of the BLR group (p = 0.025). The average observed change in the angle of deviation was 3.6 PD/mm at the final visit in all patients. A greater dose-effect relationship was observed in the ULR group than in the BLR group at the final visit (p = 0.043). CONCLUSIONS: LR advancement showed favorable motor and sensory outcomes in the majority of patients. The surgical outcome was not favorable in patients in the BLR group with consecutive esotropia of the same magnitude as the initial exotropia. These results require further investigation for verification.