Lee Ju-Yeun, Lee Eun Jung, Park Kyung-Ah, Oh Sei Yeul
Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
PLoS One. 2016 Jul 27;11(7):e0160263. doi: 10.1371/journal.pone.0160263. eCollection 2016.
The aim of this study was to investigate whether the limbus-insertion distance (LID) of the lateral rectus (LR) muscle can be a useful indicator for predicting the surgical effect of recession surgery in intermittent exotropia (IXT). Patients who underwent unilateral or bilateral LR recession for the basic type of IXT were included. The distance between the corneal limbus and the posterior edge of the insertion of LR muscle (limbus-insertion distance) was measured intraoperatively using surgical calipers (graded with 0.25 mm precision). We calculated the actual dose-response effect as the difference between the angle of preoperative deviation and the angle of postoperative deviation, and then divided the figure by the total amount of recession at postoperative months 1, 3, and 6. The correlation between the limbus-insertion distance (LID) of LR muscle and each dose-response effect was statistically analyzed. A total of 60 subjects were enrolled in this study. The mean LID of LR muscle was 5.8±0.7 mm. The dose-response effect was 3.2±1.0 prism diopters (PD)/mm at postoperative month 1, 3.4±1.0 PD/mm at postoperative month 3, and 3.4±1.1 PD/mm at postoperative month 6. The LID of the LR muscle was significantly correlated with dose-response effects in cases of unilateral and bilateral LR recession at postoperative months 3 and 6 (P = 0.01, <0.01, 0.04 and <0.01 respectively). As the LID of the LR muscle increased by 1 mm, the dose-response effect increased by 0.2PD/mm in unilateral LR recession, and by 0.4 PD/mm in bilateral LR recession at postoperative month 6. In conclusion, the LID of the LR muscle can be used as one predictor of the recession effect to assist in surgical planning for IXT. Moreover, undercorrection at the time of LR recession might be considered in patients with long LID of the LR muscle.
本研究的目的是调查外直肌（LR）的角膜缘插入距离（LID）是否可作为预测间歇性外斜视（IXT）后退手术效果的有用指标。纳入了接受单侧或双侧LR后退手术治疗基本型IXT的患者。术中使用手术卡尺（精度为0.25mm分级）测量角膜缘与LR肌插入后缘之间的距离（角膜缘插入距离）。我们将实际剂量反应效应计算为术前斜视角度与术后斜视角度之差，然后将该数值除以术后1、3和6个月的总后退量。对LR肌的角膜缘插入距离（LID）与各剂量反应效应之间的相关性进行了统计学分析。本研究共纳入60名受试者。LR肌的平均LID为5.8±0.7mm。术后1个月的剂量反应效应为3.2±1.0棱镜度（PD）/mm，术后3个月为3.4±1.0PD/mm，术后6个月为3.4±1.1PD/mm。术后3个月和6个月，单侧和双侧LR后退病例中，LR肌的LID与剂量反应效应显著相关（分别为P = 0.01、<0.01、0.04和<0.01）。术后6个月，在单侧LR后退中，随着LR肌的LID增加1mm，剂量反应效应增加0.2PD/mm；在双侧LR后退中，剂量反应效应增加0.4PD/mm。总之，LR肌的LID可作为后退效果的预测指标之一，以协助IXT的手术规划。此外，对于LR肌LID较长的患者，可能需要考虑在LR后退时进行欠矫。
