Biomechanical Analysis in Strabismus Surgery

描述(申请人提供)：斜视，双眼错位，很常见，通常手术治疗结果不理想。这是由于对眼外肌(EOM)神经支配、眼眶解剖和双眼对齐的生物力学了解不足，有时会导致错误的诊断和手术的可预见的结果。眼眶结缔组织，包括滑轮，形成一个复杂的系统，影响双眼排列和所有眼睛运动的运动学。先天性和获得性滑轮异常会导致某些类型的斜视，其他类型的斜视可能与斜视手术中对滑轮的操作有关。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了解眼球运动的机制，以及前庭-眼睛反射如何改变眼球运动的方向。我们将使用磁共振成像(MRI)来可视化EOMS和结缔组织，因为它们在正常和斜视受试者中随着注视方向和耳石影响而变化。我们将在人类身上研究耳石依赖型斜视、滑轮障碍以及新出现的滑轮手术操作后的这些功能解剖学变化。我们将研究滑轮的运动学效应并建立数学模型，包括前庭介导的眼扭转对直肌EOM牵引方向的影响，滑轮与地球之间的非插入力耦合，以及滑轮异常对符合Listing定律的影响。我们将使用MRI在活人身上直接研究获得性和遗传性先天性颅神经疾病对EOMS、EOM神经支配和双眼对准的影响。在转基因小鼠的免费实验中，我们将在显微镜下研究EOM、结缔组织和导致人类先天性斜视的突变的神经表型，我们将在人类中进行调查。相关性：该项目旨在澄清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。这种认识将改善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。研究还将阐明眼球运动异常、平衡障碍的基本遗传和机械原因，并帮助开发新出现的治疗斜视的手术。

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.