July 2019
Volume 60, Issue 9
Free
ARVO Annual Meeting Abstract  |   July 2019
Optic nerve displacements during horizontal eye movements in healthy and high myopic subjects
Author Affiliations & Notes
  • Xiaofei Wang
    Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
    Ophthalmic Engineering & Innovation Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore
  • Quan V Hoang
    Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University College of Physicians and Surgeons, New York, United States
    Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
  • Stanley Chang
    Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University College of Physicians and Surgeons, New York, United States
  • Lawrence A. Yannuzzi
    Vitreous Retina Macula Consultants of New York, New York, United States
  • K Bailey Freund
    Vitreous Retina Macula Consultants of New York, New York, United States
  • Dan Milea
    Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
    Duke-NUS Medical School, Singapore
  • Michael J A Girard
    Ophthalmic Engineering & Innovation Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore
    Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
  • Footnotes
    Commercial Relationships   Xiaofei Wang, None; Quan Hoang, None; Stanley Chang, None; Lawrence A. Yannuzzi, None; K Bailey Freund, None; Dan Milea, None; Michael Girard, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science July 2019, Vol.60, 4357. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Xiaofei Wang, Quan V Hoang, Stanley Chang, Lawrence A. Yannuzzi, K Bailey Freund, Dan Milea, Michael J A Girard; Optic nerve displacements during horizontal eye movements in healthy and high myopic subjects. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4357.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Optic nerve (ON) traction in eye movements can deform the posterior globe, which may partly contribute to axial elongation in myopia. Displacements and tortuosities of ONs may reflect the effects of ON traction. The aims of this study were to: (1) assess ON displacements in adduction and abduction using orbital MRI; (2) assess the difference in ON tortuosity and displacement during eye movements between healthy and high myopia (HM) subjects.

Methods : MRI volumes of both eyes from 18 healthy controls and 20 HM subjects in central gaze, abduction and adduction of 15° were analyzed. MRI volumes were reoriented to align with their corresponding central gaze volume through rigid translation/rotation. Images were manually-segmented in both axial and coronal views to isolate all ONs (Figure A, B). Segmented ON voxels were fitted to a 3D curve to assess ON tortuosity (Figure C), defined as the length of the ON central line segment (15 mm long from the globe-ON junction) divided by the distance between two end-points. ON displacements were evaluated in 4 quasicoronal planes which were perpendicular to the ON central line in central gaze and 3 mm apart (Figure D).

Results : Axial length measured with MRI was higher in the HM group (28.62±2.60 vs 22.84±0.89 mm; p<0.0001). ON tortuosities were larger for HM subjects in central gaze (1.043±0.041 in HM eyes vs 1.015±0.018 in controls; p=0.0002), adduction (1.039±0.039 vs 1.013±0.018; p=0.0006) and abduction (1.049±0.046 vs 1.018±0.021; p=0.0004). In all eyes, ON displacements in adduction were significantly different from those in abduction in the naso-temporal direction (p<0.0001 in all 4 planes) but not in the supero-inferior direction (p>0.27). ON moving distances in the axial plane were similar in adduction and abduction (p>0.28 in all 4 planes). ON displacements in plane 3 and 4 were smaller in the HM group in both gaze directions and were larger in plane 1 in adduction only (Figure E).

Conclusions : Horizontal eye movements induce ON displacements only in the axial plane. Therefore, 2D axial MRI scans are able to capture ON morphological changes during horizontal eye movements. In this sample, eye elongation in HM subjects resulted in a higher ON tortuosity, which may protect the posterior globe against gaze induced mechanical strains. The more ‘slack’ ONs in HM subjects allowed the ONs to move less in comparison with controls.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×