PURPOSE A-pattern exotropia, superior oblique muscle overaction, and dissociated vertical deviation may coexist and are referred to as triad exotropia. The present study evaluated the postoperative stability of horizontal ocular alignment of triad exotropia and possible prognostic factors. METHODS Medical records of patients with triad exotropia who had one-step triple surgery of superior oblique muscle weakening, superior rectus muscle recession, and lateral rectus muscle recession were reviewed. The horizontal alignment and postoperative drift of triad exotropia were analyzed and compared with constant exotropia. RESULTS The triad exotropia showed a mean of 7.7△ (± 8.5△) eso-drift, while the constant exotropia was (3.5△ ± 3.4△) exo-drift. Multiple linear regression analysis showed that the degree of superior oblique muscle overaction after surgery (P = 0.011) was the only factor associated with horizontal drift. Patients with superior oblique muscle underaction showed larger eso-drift when compared to patients without superior oblique muscle underaction (- 18.0△ ± 11.1△ vs. - 5.1△ ± 5.7△; P = 0.024). The final success rates of the triad exotropia and constant exotropia groups were 53.3% and 69.2%, respectively, and the overcorrection rates were 26.7% and 2.6% (P = 0.035). CONCLUSIONS An overall trend of eso-drift in primary position occurred in triad exotropia after triple surgery up to a follow-up of 25 months. Patients presenting superior oblique muscle underaction after surgery seemed to have large angles of eso-drift, which might be taken into account in surgical planning and follow-up.

中文翻译：

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一步三联手术后三重性眼外斜视水平眼的稳定性。

目的A型外斜视，上斜肌过度活动过度和垂直偏移分离可能并存，被称为三重性外斜视。本研究评估了三眼视力矫正的水平眼对齐的术后稳定性和可能的​​预后因素。方法回顾性分析三重性外斜视患者的一例三步手术，包括上斜肌减弱，上直肌后退和外侧直肌后退。分析了三重性外斜视的水平对准和术后漂移，并将其与恒定外斜视进行比较。结果三重性外斜视的平均内向漂移为7.7△（±8.5△），而恒定的外斜视为（3.5△±3.4△）向外漂移。多元线性回归分析表明，手术后上斜肌过度活动的程度（P = 0.011）是与水平漂移相关的唯一因素。与无上斜肌功能不足的患者相比，有上斜肌功能不足的患者表现出更大的eso漂移（-18.0△±11.1△vs.-5.1△±5.7△； P = 0.024）。三重性外斜视和恒定外斜视组的最终成功率分别为53.3％和69.2％，过矫率分别为26.7％和2.6％（P = 0.035）。结论在三联手术后至25个月的随访中，三位一体的外斜视发生了主要部位的eso漂移的总体趋势。术后出现上斜肌功能不足的患者似乎有较大的食管漂移角，