title: Predictions of Optic Nerve Traction Forces and Peripapillary Tissue Stresses Following Horizontal Eye Movements.
abstract: To use finite element (FE) analysis to predict the optic nerve sheath traction forces that act on the optic nerve head (ONH) following horizontal eye movements, and the resulting stress levels in the peripapillary connective tissues of the ONH (Bruch's membrane [BM] and sclera).
  
  
  
  An FE model of a healthy eye was reconstructed in primary gaze position that included details from the orbital and ONH tissues. Optic nerve sheath traction forces and peripapillary tissue stresses in both adduction and abduction (13°) were computed using FE analysis.
  
  
  
  Our models predicted that, following eye movements, the ONH was sheared in the transverse plane due to the pulling action of the optic nerve. The optic nerve sheath traction forces were 90 mN in abduction and 150 mN in adduction. Peripapillary tissue stresses were concentrated in the nasal and temporal quadrants. In adduction, scleral stresses were highest in the temporal region, and BM stresses were slightly higher in the nasal region. This trend was reversed in abduction.
  
  
  
  Following eye movements, our models predicted high optic nerve sheath traction forces of the same order of magnitude as extraocular muscle forces. Optic nerve traction resulted in significant peripapillary stresses, and thus may have a role to play in the development of peripapillary zones, glaucoma, and myopia.
authors.affiliation: Ophthalmic Engineering and Innovation Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wang
authors.affiliation: Ophthalmic Engineering and Innovation Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore.
authors.forename: Liam K
authors.initials: LK
authors.lastname: Fisher
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Center, Singapore 3Duke-NUS, Singapore.
authors.forename: Dan
authors.initials: D
authors.lastname: Milea
authors.affiliation: Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University, Heidelberg, Germany 5Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, and Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China.
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
authors.affiliation: Ophthalmic Engineering and Innovation Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 2Singapore Eye Research Institute, Singapore National Eye Center, Singapore.
authors.forename: Michaël J A
authors.initials: MJ
authors.lastname: Girard
mesh_terms: D001696:Biomechanical Phenomena; D005133:Eye Movements / Q000502:physiology*; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008962:Models, Theoretical; D009801:Oculomotor Muscles / Q000502:physiology*; D009898:Optic Disk / Q000502:physiology*