The relationship of age when motor alignment is achieved and the subsequent development of stereopsis in infantile esotropia.

PURPOSE: To determine the oldest age beyond which the chance of developing stereopsis is not possible even with excellent motor alignment in patients with infantile esotropia.

METHODS: The medical records of children with infantile esotropia who underwent a single operation and had alignment within 10(Δ) of orthotropia at all follow-up examinations were retrospectively reviewed. Patients were assessed for stereopsis after the age of 48 months.

RESULTS: A total of 38 children were included. There was a statistically significant inverse correlation between age at surgery and final stereopsis (r = 0.494, P = 0.002). There was a significant difference at mean age at surgery between patients having stereopsis better than 1000 arcsec and those having no stereopsis (P = 0.002). Post hoc power analysis revealed a value of 85%. Receiver operating characteristic curve analysis revealed that the optimum cut-off value of the age at surgery for predicting stereopsis was 16 months (Youden index = 0.474; area under ROC curve, 0.784; 95% CI: 0.62-0.90; P = 0.0002).

CONCLUSIONS: Surgery for infantile esotropia is most likely to result in measureable stereopsis if patient age at alignment is not more than 16 months.