Outcome study of stereopsis in relation to duration of misalignment in congenital esotropia

A recent outcome study of Randot stereopsis in congenital esotropia reported early surgical alignment is associated with a higher percentage of patients with stereopsis and a higher quality of stereopsis because early surgery minimized the duration of misalignment. We compared the Titmus stereopsis with the duration of misalignment and the age of alignment for a group of patients who were surgically aligned by 24 months of age.

The data previously obtained in a study of 90 patients aligned by 2 years of age, examined in a masked, independent evaluation for binocularity was analyzed. The age of alignment and duration of misalignment was correlated with the percentage of patients with stereopsis and quality of the stereopsis result as determined by the Titmus vectograph overlay.

Patients aligned by 6 or 12 months of age or within 6 or 12 months of duration of misalignment did not differ in percentage with stereopsis. However, patients aligned after 12 months of age did show a decrease percentage with stereopsis (P <.05, power 0.8). The quality of the stereopsis that was established was similar for those aligned by 6 or 12 months (P >.05, power 0.8). The quality of stereopsis, however, was decreased for patients with duration of misalignment greater than 12 months (P <.001, power 0.8).

Alignment within 1 year of age or within 12 months of misalignment favorably affects the percentage of patients who develop stereopsis in the treatment of congenital esotropia. The quality of the stereopsis result is affected by the duration of the misalignment, rather, than the age of alignment per se.