Long-term outcome following bilateral lateral rectus recession for intermittent exotropia

Background: Bilateral lateral rectus recession is the most common surgical treatment of intermittent exotropia in children. Success rates in previous studies differ because longer follow-up periods may change success rate as the eyes drift out with time. Initial overcorrection was thought to be appropriate management, but the preferred initial postoperative deviation has not been well quantified.

Objective: To study long-term outcomes (≥3 years) of bilateral lateral rectus recession for intermittent exotropia and to evaluate factors influencing long-term success.

Methods: This retrospective descriptive study reviews patients with intermittent exotropia who underwent bilateral lateral rectus recession with a minimum follow up of 3 years. Long-term motor outcome was classified as good (within 8 prism diopters (PD) of esodeviation and 10 PD of exodeviation), acceptable (exodeviation 11-20 PD), and poor (esotropia >8 PD or exotropia >20 PD). Stereoacuity testing pre- and postoperatively was used to evaluate sensory outcome. Correlation between long-term outcome and various pre- and postoperative factors were analyzed.

Results: A total of 59 patients met the selective inclusion criteria. The mean age at time of surgery was 7.1 years with a mean follow-up time of 4.5 years. At the time of the last visit, 69% (41 patients) had good outcomes, 24% (14 patients) had acceptable outcomes, and 7% (4 patients) had poor outcomes. Initial postoperative ocular deviation significantly correlated with long-term outcome (P < 0.05). Mean initial postoperative ocular deviation of patients with good outcome was esodeviation 12.7 PD (range ortho to esodeviation 25 PD). In 45 patients whose stereoacuity could be assessed, 58% (26 patients) had stereoacuity improvement.

Conclusion: Good long-term motor outcome can be achieved in 69% of patients following bilateral lateral rectus recession for intermittent exotropia. Initial postoperative ocular deviation correlated with long-term motor success.