Shin Hyun Jin, Park Minung, Kang Hyunkyoo, Lee Andrew G
Department of Ophthalmology, Konkuk University School of Medicine, Chungju 27478, Republic of Korea.
Department of Ophthalmology, Konkuk University Medical Center, Seoul 05030, Republic of Korea.
Biosensors (Basel). 2025 May 30;15(6):347. doi: 10.3390/bios15060347.
Understanding the tensile properties of extraocular muscles (EOMs) is crucial for successful strabismus surgery and accurate predictions of surgical outcomes. Assessments of EOM tensile strength are traditionally highly dependent on the expertise of the ophthalmic surgeon, since they involve manually pulling the EOM in opposite directions. This approach only provides subjective measurements that are not quantifiable. Previous quantitative approaches have utilized various devices such as implanted force transducers or dial tension gauges connected to muscle tendons with nylon sutures, but these methods are complex and so are rarely used outside of research settings. Consequently, the goal of this study was to create a quantitative and clinically applicable device for assessing EOM tensile strength. This developed device uses a strabismus hook connected to a strain gauge load cell that measures the tensile force and includes a tilting sensor to ensure that the hook is pulled at a consistent angle when a force is applied. The performance of the device was tested on 22 EOMs in 11 patients with intermittent exotropia during surgery for resecting the medial rectus (MR) and recessing the lateral rectus (LR) under general anesthesia. The measured tensile strengths of the MR and LR were 284.9 ± 58.3 and 278.3 ± 64.6 g (mean ± SD), respectively. In conclusion, the novel device developed in this study for quantitative measurements of EOM tensile strength in clinical settings will facilitate understanding of the pathophysiology of strabismus, as well as of the mechanical properties of the EOMs, and enhance the precision of surgical interventions.
了解眼外肌（EOMs）的拉伸特性对于斜视手术的成功以及手术结果的准确预测至关重要。传统上，眼外肌拉伸强度的评估高度依赖眼科医生的专业知识，因为这涉及手动向相反方向牵拉眼外肌。这种方法仅提供不可量化的主观测量。以前的定量方法使用了各种装置，如植入式力传感器或通过尼龙缝线连接到肌腱的表盘式张力计，但这些方法很复杂，因此很少在研究环境之外使用。因此，本研究的目的是创建一种用于评估眼外肌拉伸强度的定量且临床适用的装置。这种开发的装置使用连接到应变片称重传感器的斜视钩来测量拉伸力，并包括一个倾斜传感器，以确保在施加力时钩子以一致的角度被牵拉。在11例间歇性外斜视患者的手术中，对22条眼外肌进行了测试，手术是在全身麻醉下切除内直肌（MR）和外直肌（LR）后退。测得的内直肌和外直肌的拉伸强度分别为284.9±58.3和278.3±64.6 g（平均值±标准差）。总之，本研究开发的用于临床环境中定量测量眼外肌拉伸强度的新型装置将有助于理解斜视的病理生理学以及眼外肌的力学特性，并提高手术干预的精度。
