The Effect of Preoperative Occlusion Therapy on Long-term Outcome after Surgery for Early-onset Exotropia

Abstract

Purpose: To investigate the effect of preoperative part-time occlusion therapy on long-term surgical successin early-onset exotropia. Methods: The medical records of patients who underwent surgery for exotropia with onset before the firstyear of age and who were followed for ≥3 years were reviewed. Patients were divided into two groups accordingto the degree of compliance with part-time occlusion therapy: the good compliance group (>50%adherence rate) and the poor compliance group (≤50% adherence rate). Surgical success was defined asorthophoria to exodeviation less than 10 prism diopters both at distance and near. The level of postoperativestereopsis was compared between the two study groups among total enrolled patients and among thosewith constant exotropia. Results: Of the 51 patients, 26 were assigned to the good compliance group and the remaining 25 patients tothe poor compliance group. The surgical success rate was significantly higher in the good compliance groupthan in the poor compliance group (80.8% vs. 52.0%, p = 0.040). Among 24 constant exotropia patients (12patients for each group), the success rate was insignificantly higher in the good compliance group than in thepoor compliance group (75.0% vs. 58.3%, p = 0.448). The good compliance group had a better level of stereopsisthan the poor compliance group (p = 0.045 for all 44 patients, p = 0.020 for 19 patients with constantexotropia). Conclusions: Preoperative part-time occlusion therapy was useful for improving the surgical outcome of early-onset exotropia and postoperative stereopsis.