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. ? ?

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY008313-18
Application #
7496404
Study Section
Sensorimotor Integration Study Section (SMI)
Program Officer
Araj, Houmam H
Project Start
1991-01-06
Project End
2011-04-30
Budget Start
2008-05-01
Budget End
2009-04-30
Support Year
18
Fiscal Year
2008
Total Cost
$519,959
Indirect Cost
Name
University of California Los Angeles
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Chaudhuri, Zia; Demer, Joseph L (2018) Long-term Surgical Outcomes in the Sagging Eye Syndrome. Strabismus 26:6-10
Demer, Joseph L (2018) Knobby Eye Syndrome. Strabismus 26:33-41
Clark, Robert A; Demer, Joseph L (2018) The Globe's Eccentric Rotational Axis: Why Medial Rectus Surgery Is More Potent than Lateral Rectus Surgery. Ophthalmology 125:1234-1238
Shin, Andrew; Park, Joseph; Demer, Joseph L (2018) Opto-mechanical characterization of sclera by polarization sensitive optical coherence tomography. J Biomech 72:173-179
Demer, Joseph L; Clark, Robert A; Suh, Soh Youn et al. (2017) Magnetic Resonance Imaging of Optic Nerve Traction During Adduction in Primary Open-Angle Glaucoma With Normal Intraocular Pressure. Invest Ophthalmol Vis Sci 58:4114-4125
Chang, Melinda Y; Coleman, Anne L; Tseng, Victoria L et al. (2017) Surgical interventions for vertical strabismus in superior oblique palsy. Cochrane Database Syst Rev 11:CD012447
Shin, Andrew; Yoo, Lawrence; Park, Joseph et al. (2017) Finite Element Biomechanics of Optic Nerve Sheath Traction in Adduction. J Biomech Eng 139:
Suh, Soh Youn; Le, Alan; Shin, Andrew et al. (2017) Progressive Deformation of the Optic Nerve Head and Peripapillary Structures by Graded Horizontal Duction. Invest Ophthalmol Vis Sci 58:5015-5021
Rajab, Ghada Z; Suh, Soh Youn; Demer, Joseph L (2017) Magnetic resonance imaging in dissociated strabismus complex demonstrates generalized hypertrophy of rectus extraocular muscles. J AAPOS 21:205-209
Chang, Melinda Y; Shin, Andrew; Park, Joseph et al. (2017) Deformation of Optic Nerve Head and Peripapillary Tissues by Horizontal Duction. Am J Ophthalmol 174:85-94

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