Consecutive exotropia after surgical treatment of childhood esotropia: a 40-year follow-up study

Abstract

Purpose: To determine the incidence of consecutive exotropia (XT) following successful surgical correction of childhood esotropia (ET) and identify factors associated with its development.

Material and methods: This is a retrospective study of 85 patients with ET, aged 2-24, who underwent strabismus surgery by a single surgeon between 1958 and 1969 in Sweden, until they were successfully aligned to ET within 10 prism dioptre, after primary or reoperation(s). The charts of these patients were reviewed, and data regarding age at onset of strabismus, surgery performed and outcome were recorded. The patients were recalled for a complete orthoptic examination in 2001-2003.

Results: The incidence of consecutive XT in this cohort was 21% (18/85). Patients who had undergone multiple surgeries had a higher risk of developing consecutive XT compared to those successfully aligned with one surgery (p = 0.00036). Restriction of adduction and convergence postoperatively was associated with a high risk of consecutive XT (p = 0.0437). The incidence of consecutive XT did not vary with the level of visual acuity in the operated eye (p = 0.6428). Age of onset, age at surgery and amount of surgery did not appear to influence the risk for developing consecutive XT (p > 0.05).

Conclusion: This 40-year postoperative follow-up of patients with childhood ET who underwent strabismus surgery by a single surgeon in Sweden showed that multiple surgeries and presence of postoperative adduction deficit were the most important factors influencing the incidence of consecutive XT after surgery. Presence of uncorrected amblyopia did not alter the prognosis for long-term development of consecutive XT.