Abstract：
BACKGROUND: Lagophthalmos and lid lag is the most common complication after ptosis correction. Great efforts had been made to control it, but little was known about the factors influencing it. So we ran this research to explore the possible mechanisms underlying it. This would be beneficial to solving this problem.
METHODS: In this cohort study, patients treated with the forked frontalis muscle aponeurosis suspension and levator aponeurosis-Muller\'s muscle complex resection were identified. Lagophthalmos height and lid lag was measured at the postoperative week 1 visits. The Spearman correlation test was run to test whether lagophthalmos was related to patients\' age, levator function, and severity of ptosis. Then we measured the contents of collagen and elastin fibers of frontalis muscle fascia and levator aponeurosis from the patients and levator aponeurosis from cadaver heads histologically and compared the contents in these 3 groups.
RESULTS: No correlation was found between patients\' age, levator function, the severity of ptosis, and with lagophthalmos height. However, the contents of collagen and elastic fibers were both higher in the frontalis fascia than in the normal aponeurosis tissues. The difference in collagen fibers content between frontalis muscle fascia and patients\' aponeurosis was statistically insignificant.
CONCLUSIONS: The severe lagophthalmos and lid lag may be caused by the poor mechanical features of the frontalis muscle. A better source of motive force to elevate the eyelids and a novel sling material with proper elasticity and stiffness would be the solution to improve the lagophthalmos and lid lag after ptosis correction.
METHODS: In this cohort study, patients treated with the forked frontalis muscle aponeurosis suspension and levator aponeurosis-Muller\'s muscle complex resection were identified. Lagophthalmos height and lid lag was measured at the postoperative week 1 visits. The Spearman correlation test was run to test whether lagophthalmos was related to patients\' age, levator function, and severity of ptosis. Then we measured the contents of collagen and elastin fibers of frontalis muscle fascia and levator aponeurosis from the patients and levator aponeurosis from cadaver heads histologically and compared the contents in these 3 groups.
RESULTS: No correlation was found between patients\' age, levator function, the severity of ptosis, and with lagophthalmos height. However, the contents of collagen and elastic fibers were both higher in the frontalis fascia than in the normal aponeurosis tissues. The difference in collagen fibers content between frontalis muscle fascia and patients\' aponeurosis was statistically insignificant.
CONCLUSIONS: The severe lagophthalmos and lid lag may be caused by the poor mechanical features of the frontalis muscle. A better source of motive force to elevate the eyelids and a novel sling material with proper elasticity and stiffness would be the solution to improve the lagophthalmos and lid lag after ptosis correction.
摘要：
背景：隐眼和眼睑迟滞是上睑下垂矫正后最常见的并发症。已经做出了巨大的努力来控制它，但是对影响它的因素知之甚少。因此，我们进行了这项研究，以探索潜在的机制。这将有利于解决这个问题。
方法：在这项队列研究中，患者接受叉形额肌肌腱膜悬吊术和提肌肌腱膜-穆勒肌肉复合体切除术治疗。在术后第1周就诊时测量眼高和眼睑滞后。进行Spearman相关性检验以检验痛眼是否与患者年龄有关,提升机功能，和上睑下垂的严重程度。然后从组织学上测量了患者额肌筋膜和提肌肌腱膜的胶原蛋白和弹性纤维的含量，并比较了这3组的含量。
结果：没有发现患者年龄之间的相关性，提升机功能，上睑下垂的严重程度,眼高。然而,额筋膜中的胶原蛋白和弹性纤维含量均高于正常的肌腱膜组织。额肌筋膜与患者的胶原纤维含量差异无统计学意义。
结论：严重的眼睑迟滞和眼睑迟滞可能是由于额肌的力学特征差所致。提升眼睑的更好的动力来源以及具有适当弹性和刚度的新型吊带材料将是改善上睑下垂矫正后的眼睑和眼睑滞后的解决方案。
方法：在这项队列研究中，
结果：没有发现患者年龄之间的相关性，
结论：严重的眼睑迟滞和眼睑迟滞可能是由于额肌的力学特征差所致。
