Xue Zhipeng, Min Xiaoshan, Wang Jieyue, Zhu Ying, He Sujun, Liu Kangcheng, Ding Yi
Department of Ophthalmology, Xiangya Hospital Central South University, Changsha 410000, Hunan, China.
Changsha Jiqiang Eye Hospital, Changsha 410000, Hunan, China.
J Ophthalmol. 2020 Apr 21;2020:3039180. doi: 10.1155/2020/3039180. eCollection 2020.
To summarize the clinical manifestations, diagnosis, treatment, and prognosis for inferior oblique muscle ectopia (IO-E). . Patients diagnosed with IO-E during strabismus surgery from March 2017 to September 2018 were included in this retrospective, cross-sectional study. All patients received preoperative Krimsky test, synoptophore, cycloplegia refraction, fundus torsion, and other strabismus-related specific tests. The anatomic variations of IO-E were always discovered during surgical procedure. Postoperative eye position and binocular visual function (BVF) were all reviewed in early days after operation.
A total of 7 patients were enrolled in this study with an average age of 6.4 ± 3.8 yrs. They all presented with significant exotropia and unilateral (or bilateral) overelevation in adduction (OEA). No compensatory head position was detected. Some of them had vertical deviation, V pattern, or excyclotropia, which were indicated by fundus torsion. Monocular or binocular IO-E was distinguished during the surgery, and it could be classified into two types according to its anatomic features. In surgery, the ectopic IO muscle bundle was restored, and different IO weakening methods were employed. Meanwhile, the horizontal deviation was also corrected according to the preoperative examination. Eyes of all patients were properly aligned in the primary position after surgery. Varying degrees of BVF appeared in 3 cases.
IO-E is a rare congenital dysplasia variation of the extraocular muscle, which could appear as inferior oblique overaction. It is difficult to diagnose before surgery, and weakening the overactive ectopic inferior oblique was required for better prognosis if this condition was confirmed during surgery.
总结下斜肌异位（IO-E）的临床表现、诊断、治疗及预后。纳入2017年3月至2018年9月斜视手术中诊断为IO-E的患者进行这项回顾性横断面研究。所有患者均接受术前克里姆斯基试验、同视机检查、睫状肌麻痹验光、眼底扭转及其他斜视相关专项检查。IO-E的解剖变异均在手术过程中发现。术后早期复查眼位及双眼视功能（BVF）。
本研究共纳入7例患者，平均年龄6.4±3.8岁。所有患者均表现为明显的外斜视及内收时单眼（或双眼）上斜（OEA）。未发现代偿头位。部分患者存在垂直斜视、V型斜视或外旋转斜视，由眼底扭转提示。手术中区分单眼或双眼IO-E，并根据其解剖特征分为两种类型。手术中，将异位的下斜肌肌束复位，并采用不同的下斜肌减弱方法。同时，根据术前检查结果矫正水平斜视。术后所有患者的眼位在第一眼位均矫正良好。3例患者出现不同程度的BVF。
IO-E是一种罕见的眼外肌先天性发育异常变异，可表现为下斜肌亢进。术前难以诊断，若手术中确诊此病，为获得更好的预后，需减弱亢进的异位下斜肌。
