The long-term survival analysis of bilateral lateral rectus recession versus unilateral recession-resection for intermittent exotropia

Abstract

Purpose: To conduct a comparison of the long-term surgical outcomes of bilateral lateral rectus recession (BLR) vs unilateral lateral rectus recession-medial rectus resection (RR) in treatment of intermittent exotropia.

Design: Nonrandomized, retrospective case series.

Methods: Consecutive patients who underwent BLR or RR for treatment of intermittent exotropia between 2002 and 2006 and had ≥2 years' follow-up were recruited. Surgical outcomes were grouped according to postoperative angle of deviation as overcorrection (esophoria/tropia >5 Δ), success (esophoria/tropia ≤5 Δ to exophoria/tropia ≤10 Δ), or undercorrection/recurrence (exophoria/tropia >10 Δ), and were compared between the BLR group and the RR group at postoperative 1 day, 1 month, 6 months, 1 year, and 2 years, and at the final examination.

Results: Of 128 patients, 55 underwent BLR and 73 underwent RR. The mean follow-up period was 44.2 months in the BLR group and 47.8 months in the RR group. At 1 day, 1 month, 6 months, 1 year, and 2 years after surgery, surgical outcomes in each group were not different (P > .05) However, the final outcome at a mean of 3.8 years was significantly different between the groups, demonstrating a higher success rate in the BLR group than in the RR group (58.2% vs 27.4%, P < .01). Cumulative probability of survival from recurrence was higher in the BLR group than in the RR group (P = .01, log-rank test). Recurrences were most common within 6 months from surgery; however, after that, recurrences occurred continuously in the RR group and rarely in the BLR group.

Conclusion: Surgical outcomes by 2 years after surgery for intermittent exotropia were not different between the BLR and RR groups. However, final outcomes were better in the BLR group than in the RR group. This may be caused by the difference of recurrence rate over time: continuous recurrence of exotropia occurred in the RR group, while recurrence was low in the BLR group after postoperative 6 months.