Surgical data and outcomes (N = 27).

Purpose
Induced vertical deviation is a potential complication following the Nishida procedure for the treatment of sixth nerve palsy. This study aims to compare different positioning techniques for the reduction of this complication.
Methods
We retrospectively examined medical records from consecutive patients who underwent the Nishida procedure, classifying them into three positioning groups: intra-quadrant (IQP), lateral rectus border (LRBP), and horizontal meridian (HMP). Surgical and pre/postoperative data were compared.
Results
Among the 27 included patients (8 IQP, 9 LRBP, 10 HMP), all three groups demonstrated similar reductions in esodeviation: IQP, 44.0 ± 18.7 Prism Diopters (PD); LRBP, 42.2 ± 15.3 PD; HMP, 42.2 ± 7.8 PD; (P = 0.675). After surgery, one patient in the IQP group developed hypertropia of 18 PD, necessitating a secondary surgery to treat the vertical diplopia. In the LRBP group, two patients had hypotropia of 30 PD and 10 PD, respectively, and one patient had hypertropia of 6 PD. In the HMP group, one patient initially had hypertropia of 2 PD, which resolved during subsequent follow-up. A lower incidence of induced vertical deviation was observed in the HMP (10%) and IQP (13%) groups compared to the LRBP group (33%). However, this difference did not reach statistical significance due to the small sample size.
Conclusion
There is no statistically significant difference among the three positioning techniques (IQP, LRBP, HMP) in the correction of esodeviation and reduction of incidence of induced vertical deviation following Nishida procedure.

研究目的：诱发垂直斜视（induced vertical deviation）是治疗外展神经麻痹（sixth nerve palsy）时采用西田手术（Nishida procedure）后可能出现的潜在并发症。本研究旨在对比不同缝合定位技术，以降低该并发症的发生风险。
研究方法：本研究回顾性分析连续接受西田手术患者的病历资料，按缝合定位方式将其分为三组：象限内定位法（intra-quadrant, IQP）、外直肌缘定位法（lateral rectus border, LRBP）以及水平子午线定位法（horizontal meridian, HMP），并对三组患者的手术相关资料及术前、术后随访数据进行对比分析。
研究结果：本研究共纳入27例患者（IQP组8例、LRBP组9例、HMP组10例），三组患者的内斜视（esodeviation）矫正量均无显著差异：IQP组为44.0±18.7棱镜度数（Prism Diopters, PD），LRBP组为42.2±15.3 PD，HMP组为42.2±7.8 PD（P=0.675）。术后，IQP组有1例患者出现18 PD的上斜视（hypertropia），需接受二次手术以治疗垂直性复视（vertical diplopia）；LRBP组有2例患者分别出现30 PD和10 PD的下斜视（hypotropia），另有1例患者出现6 PD的上斜视；HMP组有1例患者初始出现2 PD的上斜视，该症状在后续随访中自行缓解。与LRBP组的33%相比，HMP组（10%）与IQP组（13%）的诱发垂直斜视发生率更低，但因样本量较小，该差异未达到统计学显著性。
研究结论：在西田手术后的内斜视矫正以及诱发垂直斜视发生率的降低方面，三种缝合定位技术（IQP、LRBP、HMP）之间均无统计学意义上的显著差异。