<p>Surgical dosages of RR in group 1 and group 2.</p>

Aim We compared the surgical outcomes of monocular lateral rectus recession–medial rectus resection (RR) for convergence insufficiency-type intermittent exotropia (CI-type IXT) using two different formulas. Methods A retrospective review of patients who underwent unilateral RR for CI-type IXT with at least 6 months follow-up was done. In group 1 (58 patients), RR was determined based on the average of distance and near exodeviation. In group 2 (80 patients), lateral rectus (LR) recession amount was based on the exodeviation at distance and medial rectus (MR) resection was done as the same amount of LR recession (symmetric RR). Results Group 2 showed greater esodeviation at distance and near until postoperative 1 month, however, there was no significant difference in deviation angles between the two groups from 3 to 24 months. Both groups showed significant reduction in near-distance difference up to postoperative 24 months (p < 0.05): from 8.3 PD preoperatively to 1.0 at 24 months in group 1 and from 9.3 to 3.8 in group 2. The success rate at 24 months was 72.7% and 67.6% in group 1 and 2, respectively (p = 0.795). Conclusion RR based on the average of distance and near exodeviation and the symmetric RR can successfully collapse the near–distance difference while achieving favorable surgical outcomes.研究目的 本研究对比了采用两种不同手术量计算公式，行单眼外直肌后徙-内直肌截除术（RR）治疗集合不足型间歇性外斜视（CI-type IXT）的手术疗效。 研究方法 本研究对接受单眼RR手术治疗CI-type IXT且随访时间至少6个月的患者进行回顾性分析。第1组（58例患者）的手术量根据远距与近距外斜视度的平均值确定；第2组（80例患者）的外直肌（LR）后徙量根据远距外斜视度确定，且内直肌（MR）截除量与外直肌后徙量保持一致（对称式RR手术）。 研究结果 直至术后1个月，第2组患者的远距与近距内斜视度均更高；但在术后3至24个月期间，两组患者的斜视度无显著差异。两组患者的近远距斜视差均在术后24个月时出现显著降低（p<0.05）：第1组从术前的8.3 PD降至术后24个月时的1.0 PD，第2组则从9.3 PD降至3.8 PD。术后24个月时，第1组与第2组的手术成功率分别为72.7%与67.6%（p=0.795）。 研究结论 基于远距与近距外斜视度平均值的RR手术与对称式RR手术，均可在获得良好手术疗效的同时，有效缩小近远距斜视差。