Optimal surgical timing in infantile exotropia

Objective To evaluate age at surgery and duration of misalignment, which affect surgical outcomes of infantile exotropia in healthy children younger than 1 year. Methods The charts of 39 patients who have at least 1 year of follow-up period after surgery with a diagnosis of early-onset exotropia were reviewed retrospectively. Patients were divided into 2 groups (preoperative deviation [PD]): success (exodeviation ≤8 PD or esodeviation ≤5 PD at 1 year postoperatively without reoperation in the whole follow-up period) or failure (exodeviation >8 PD or esodeviation >5 PD at 1 year postoperatively, or reoperation for recurrence or overcorrection during the follow-up period). We evaluated the age at surgery and the duration of misalignment divided into 5 categories - before 6, 12, 18, 24, and 30 months - to suggest appropriate surgical timing affecting surgical outcome and compared between the 2 groups. Results Overall, 74% of the patients comprised the success group and 26% the failure group. There was no statistically significant difference in the age of alignment between 2 groups (p = 0.91). The mean duration of misalignment was 16.7 months in the success group and 20.1 months in the failure group, with no significant difference (p = 0.52). There were 4 patients (14%) with a misalignment duration of ≥24 months in the success group and 5 such patients (50%) in the failure group; the difference was statistically significant (p = 0.024). Therefore, with a duration of misalignment of up to 24 months as the reference level, the odds of having a successful outcome decreased significantly over 24 months, with the multiple logistic regression model yielding a risk estimate over 6-fold of failure (odds ratio 6.25; p = 0.024). Conclusions The postoperative surgical outcome was influenced by the duration of the misalignment, rather than the age at surgery. Surgery within 24 months of misalignment favourably affected the percentage of patients who achieved successful outcome in the treatment of infantile exotropia.