Biomechanical Analysis in Strabismus Surgery

描述（由申请人提供）：斜视，双眼错位，是普遍存在的，通常手术治疗效果不完美。这是由于对眼外肌（EOM）神经支配、眼眶解剖和双眼对准的生物力学了解不足，有时会导致错误的诊断和手术。眼眶结缔组织，包括滑轮，形成一个复杂的系统，影响双眼对准和所有眼球运动的运动学。先天性和获得性滑轮组异常可导致某些类型的斜视，而其他类型的斜视可能与斜视手术中滑轮组的操作有关。我们提出了一种多学科的方法，通过对人类和动物的平行研究来理解眼球运动的机制，以及前庭-眼反射如何改变EOM的拉动方向。我们将使用磁共振成像（MRI）来观察正常和斜视受试者的EOMs和结缔组织随着凝视方向和耳石影响的变化。我们将在人类中研究耳石依赖性斜视、滑轮疾病的这些功能性解剖变化，以及随之而来的滑轮手术操作的表现。我们将研究滑轮的运动学影响并建立数学模型，包括前庭介导的眼扭转对直肌EOM拉动方向的影响，滑轮与眼球的非插入力耦合，以及滑轮异常对符合李氏定律的影响。我们将使用MRI直接在活人身上研究获得性和遗传特征的先天性脑神经病变对EOM、EOM神经支配和双眼对准的影响。在转基因小鼠的补充实验中，我们将在显微镜下研究引起先天性斜视的EOM、结缔组织和神经表型突变，我们将在人类中研究。相关性：该项目旨在阐明对肌肉和韧带的理解，这些肌肉和韧带负责保持两只眼睛在单一视觉中对齐。这一认识将提高交叉和斜视的诊断和手术治疗，这是导致复视和视力丧失的常见问题。研究还将阐明眼球异常运动、平衡障碍的基本遗传和机械原因，并有助于发展治疗斜视的新手术。

DESCRIPTION (provided by applicant): Strabismus, binocular misalignment, is prevalent and usually treated surgically with imperfect outcomes. This is the predictable result of inadequate understanding of extraocular muscle (EOM) innervation, orbital anatomy, and the biomechanics of binocular alignment, sometimes leading to erroneous diagnoses and surgery. Orbital connective tissues, including pulleys, form a complex system influencing binocular alignment and kinematics of all eye movements. Congenital and acquired pulley abnormalities cause some types of strabismus, and others may be related to manipulations of pulleys during strabismus surgery. We propose a multidisciplinary approach to understanding the mechanics of eye movement through parallel studies in humans and animals, and how EOM pulling directions are altered by vestibulo-ocular reflexes. We will employ magnetic resonance imaging (MRI) to visualize EOMs and connective tissues as they change with gaze direction and otolith influences in normal and strabismic subjects. We will investigate in humans these functional anatomical changes in otolith-dependent strabismus, pulley disorders, and following performance of emerging surgical manipulations of pulleys. We will investigate and mathematically model the kinematic effects of pulleys, including effects of vestibularly-mediated eye torsion on rectus EOM pulling directions, non-insertional force coupling from pulleys to the globe, and effects of pulley abnormalities on conformity to Listing's Law. We will employ MRI to study directly in living humans the effects of acquired and genetically characterized congenital cranial neuropathies on EOMs, EOM innervation, and binocular alignment. In complimentary experiments in genetically modified mice, we will microscopically study EOM, connective tissues, and nerve phenotypes of mutations causing the congenital forms of strabismus we will investigate in humans. Relevance: This project aims to clarify understanding of muscles and ligaments responsible for keeping the two eyes aligned for single vision. This understanding will improve diagnosis and surgical treatment of crossed and deviated eyes, common problems leading to double vision and visual loss. Studies will also clarify basic genetic and mechanical causes of abnormal eye movements, balance disorders, and aid development of newly-emerging surgeries for treating strabismus.