Evidence for a pulley of the inferior oblique muscle
Evidence for a pulley of the inferior oblique muscle
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DOI：
10.1167/iovs.03-0160
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发表时间：
2003-09-01
影响因子：
4.4
通讯作者：
Poukens, V
中科院分区：
文献类型：
--
作者：
Demer, JL;Oh, SY;Poukens, V
目的。本研究旨在调查结缔组织滑轮约束下斜肌（IO）路径的证据。从磁共振图像中，确定了在多个凝视位置下人类IO的横截面积、路径和轨道关系。静脉注射加多二胺造影剂直接对直肌滑车成像。图像与人类和猴子IO肌肉的连续组织学切片进行了比较。从起点到下直肌（IR）外侧边界的IO路径是直的。在红外侧面，IO弯曲跟随地球。在红外交叉点，IO从红外插入到生产的行程约为红外插入行程的53%。在IR中心附近，IO横截面的注视相关变化是可证实的。IO路径凝视相关的屈曲对应于其被一个由胶原蛋白密集环组成的滑轮包围，由弹性蛋白和平滑肌硬化，并与IR滑轮结合。眶层纤维嵌入内窝滑车、外侧直肌滑车及相关结缔组织。像直肌一样，人类和猴子的IO有一个结缔组织滑轮作为其功能起源。IO滑轮的位置受其与主动移动的IR滑轮的耦合的影响，而反过来IO轨道层插入并可能移动IR和LR滑轮。这些相互耦合有助于通过眼外直肌悬架实现交换性眼运动装置。
PURPOSE. This study was undertaken to investigate evidence for a connective tissue pulley constraining the,path of the inferior oblique (IO) muscle.METHODS. From magnetic resonance images, the cross-sectional area, path, and orbital relationships of the human IO were determined in multiple gaze positions. Rectus pulleys were directly imaged with intravenous gadodiamide contrast. Images were compared with serial histologic sections of IO muscles of humans and monkeys.RESULTS. The IO path from origin to the lateral border of the inferior rectus (IR) muscle was straight. Lateral to the IR, the IO curved to follow the globe. At the point of IR crossing, the IO moved anteriorly from infraduction to supraduction by approximately 53% of the IR insertion's travel. Gaze-related change in IO cross section was demonstrable near the IR center. The gaze-related inflection in IO path corresponded to its encirclement by a pulley consisting of a dense ring of collagen, stiffened by elastin and smooth muscle, and united with the IR pulley. Orbital layer fibers of the IO inserted on its pulley, the lateral rectus (LR) pulley, and associated connective tissues.CONCLUSIONS. Like the rectus muscles, the human and monkey IO has a connective tissue pulley serving as its functional origin. The position of the IO pulley is influenced by its coupling to the actively moving IR pulley, whereas in turn the IO orbital layer inserts on and presumably shifts the IR and LR pulleys. These intercouplings facilitate implementation by rectus extraocular muscle suspensions of a commutative ocular motor plant.