scholarly journals Predictions of Optic Nerve Traction Forces and Peripapillary Tissue Stresses Following Horizontal Eye Movements

2017 ◽  
Vol 58 (4) ◽  
pp. 2044 ◽  
Author(s):  
Xiaofei Wang ◽  
Liam K. Fisher ◽  
Dan Milea ◽  
Jost B. Jonas ◽  
Michaël J. A. Girard
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Traction Forces ◽  
Tissue Stresses

scholarly journals Optic nerve tortuosity and displacements during horizontal eye movements in healthy and highly myopic subjects

2021 ◽  
pp. bjophthalmol-2021-318968
Author(s):  
Xiaofei Wang ◽  
Stanley Chang ◽  
Jack Grinband ◽  
Lawrence A Yannuzzi ◽  
K Bailey Freund ◽  
...  
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Axial Length ◽  
Traction Forces ◽  
Axial Elongation ◽  
3 Dimensional ◽  
Potential Link ◽  
Temporal Direction

Aims(1) To assess the morphology and 3-dimensional (3D) displacements of the eye globe and optic nerve (ON) in adduction/abduction using MRI. (2) To assess differences between healthy emmetropic and highly myopic (HM) subjects.MethodsMRI volumes of both eyes from 18 controls and 20 HM subjects in primary gaze, abduction and adduction (15°) were postprocessed. All ONs were manually segmented and fitted to a 3D curve to assess ON tortuosity. ON displacements were evaluated in four quasicoronal planes which were perpendicular to the ON in primary gaze and were 3 mm apart.ResultsAxial length was higher in the HM group (28.62±2.60 vs 22.84±0.89 mm; p<0.0001). Adjusted ON tortuosities (ie, ON tortuosities estimated before myopia onset) were lower in HM eyes (0.9063±0.0591) versus controls (1.0152±0.02981) in primary gaze, adduction (0.9023±0.05538 vs 1.0137±0.0299) and abduction (0.9100±0.0594 vs 1.0182±0.0316); p<0.0001 for all cases. In all eyes, ON displacements in adduction were significantly different from those in abduction in the naso-temporal direction (p<0.0001 in all planes) but not in the supero-inferior direction. ON displacements in the posterior segments of the ON were smaller in the HM group in both gaze directions and were larger in the anterior-most ON segment in adduction only.ConclusionThe adjusted tortuosity of the ON was significantly lower in HM eyes, suggesting that eyes destined towards HM exhibited higher ON traction forces during eye movements before the onset of myopia. Our ON metrics may be valuable to explore a potential link between eye movements and axial elongation.

scholarly journals Optic nerve tortuosity and displacements during horizontal eye movements in healthy and highly myopic subjects

2020 ◽  
Author(s):  
Xiaofei Wang ◽  
Stanley Chang ◽  
Jack Grinband ◽  
Lawrence A. Yannuzzi ◽  
K. Bailey Freund ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Eye Movements ◽  
Optic Nerve ◽  
Magnetic Resonance ◽  
Axial Length ◽  
Resonance Imaging ◽  
Traction Forces ◽  
Potential Link ◽  
Magnetic Resonance Imaging Mri ◽  
Temporal Direction

ABSTRACTPurpose(1) To assess the morphology and 3D displacements of the eye globe and optic nerve (ON) in adduction/abduction using magnetic resonance imaging (MRI). (2) To assess differences between healthy emmetropic and highly myopic (HM) subjects.MethodsMRI volumes of both eyes from 18 controls and 20 HM subjects in primary gaze, abduction and adduction (15°) were postprocessed. All ONs were manually-segmented and fitted to a 3D curve to assess ON tortuosity. ON displacements were evaluated in 4 quasicoronal planes which were perpendicular to the ON in primary gaze and 3 mm apart.ResultsAxial length was higher in the HM group (28.62±2.60 vs 22.84±0.89 mm; p<0.0001). Adjusted ON tortuosities (i.e., ON tortuosities estimated before myopia onset) were lower in HM eyes (0.9063±0.0591) versus controls (1.0152±0.02981) in primary gaze, adduction (0.9023±0.05538 versus 1.0137±0.0299) and abduction (0.9100±0.0594 versus 1.0182±0.0316); p<0.0001 for all cases. In all eyes, ON displacements in adduction were significantly different from those in abduction in the naso-temporal direction (p<0.0001 in all planes) but not in the supero-inferior direction. ON displacements in the posterior segments of the ON were smaller in the HM group in both gaze directions and were larger in the anterior-most ON segment in adduction only.ConclusionsThe adjusted tortuosity of the ON was significantly lower in HM eyes, suggesting that eyes destined toward HM exhibited higher ON traction forces during eye movements before the onset of myopia. Our ON metrics may be valuable to explore a potential link between eye movements and axial elongation.

scholarly journals Gaze-evoked deformations of the optic nerve head in thyroid eye disease

2020 ◽  
Author(s):  
Liam K. Fisher ◽  
Xiaofei Wang ◽  
Tin A. Tun ◽  
Hsi-Wei Chung ◽  
Dan Milea ◽  
...  
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Tilt Angle ◽  
Computational Models ◽  
Human Subjects ◽  
Computational Modelling ◽  
Thyroid Eye Disease ◽  
Eye Disease ◽  
Angle Measurements

AbstractPurposeTo assess gaze evoked deformations of the optic nerve head (ONH) in thyroid eye disease (TED), using computational modelling and optical coherence tomography (OCT).MethodsMultiple finite element models were constructed: One model of a healthy eye, and two models mimicking effects of TED; one with proptosis and another with extraocular tissue stiffening. Two additional hypothetical models had extraocular tissue softening or no extraocular tissue at all. Horizontal eye movements were simulated in these models.OCT images of the ONH of 10 healthy volunteers and 1 patient with TED were taken in primary gaze. Additional images were recorded in the same subjects performing eye movements in adduction and abduction.The resulting ONH deformation in the models and human subjects was measured by recording the ‘tilt angle’ (relative antero-posterior deformation of the Bruch’s membrane opening). Effective stress was measured in the peripapillary sclera of the models.ResultsIn our computational models the eyes with proptosis and stiffer extraocular tissue had greater gaze-evoked deformations than the healthy eye model, while the models with softer or no extraocular tissue had lesser deformations, in both adduction and abduction. Scleral stress correlated with the tilt angle measurements.In healthy subjects, the mean tilt angle was 1.46° ± 0.25 in adduction and −0.42° ± 0.12 in abduction. The tilt angle measured in the subject with TED was 5.37° in adduction and −2.21° in abduction.ConclusionsComputational modelling and experimental observation suggest that TED can cause increased gaze-evoked deformations of the ONH.

scholarly journals In Vivo 3-Dimensional Strain Mapping Confirms Large Optic Nerve Head Deformations Following Horizontal Eye Movements

2016 ◽  
Vol 57 (13) ◽  
pp. 5825 ◽  
Author(s):  
Xiaofei Wang ◽  
Meghna R. Beotra ◽  
Tin Aung Tun ◽  
Mani Baskaran ◽  
Shamira Perera ◽  
...  
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Strain Mapping ◽  
3 Dimensional

scholarly journals Finite Element Analysis Predicts Large Optic Nerve Head Strains During Horizontal Eye Movements

2016 ◽  
Vol 57 (6) ◽  
pp. 2452 ◽  
Author(s):  
Xiaofei Wang ◽  
Helmut Rumpel ◽  
Winston Eng Hoe Lim ◽  
Mani Baskaran ◽  
Shamira A. Perera ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Eye Movements ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Element Analysis

scholarly journals Changes in the optic nerve head induced by horizontal eye movements

PLoS ONE ◽  
2018 ◽  
Vol 13 (9) ◽  
pp. e0204069 ◽  
Author(s):  
Won June Lee ◽  
Yu Jeong Kim ◽  
Ji Hong Kim ◽  
Sunjin Hwang ◽  
Seung Hak Shin ◽  
...  
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Optic Nerve Head

scholarly journals Gaze-evoked deformations of the optic nerve head in thyroid eye disease

2021 ◽  
pp. bjophthalmol-2020-318246
Author(s):  
Liam K Fisher ◽  
Xiaofei Wang ◽  
Tin A Tun ◽  
Hsi-Wei Chung ◽  
Dan Milea ◽  
...  
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Tilt Angle ◽  
Computational Models ◽  
Human Subjects ◽  
Computational Modelling ◽  
Thyroid Eye Disease ◽  
Eye Disease ◽  
The Subject

PurposeTo assess gaze evoked deformations of the optic nerve head (ONH) in thyroid eye disease (TED), using computational modelling and optical coherence tomography (OCT).MethodsMultiple finite element models were constructed: one model of a healthy eye, and two models mimicking effects of TED; one with proptosis and another with extraocular tissue stiffening. Two additional hypothetical models had extraocular tissue softening or no extraocular tissue at all. Horizontal eye movements were simulated in these models. OCT images of the ONH of 10 healthy volunteers and 1 patient with TED were taken in primary gaze. Additional images were recorded in the same subjects performing eye movements in adduction and abduction. The resulting ONH deformation in the models and human subjects was measured by recording the ‘tilt angle’ (relative antero-posterior deformation of the Bruch’s membrane opening).ResultsIn our computational models the eyes with proptosis and stiffer extraocular tissue had greater gaze-evoked deformations than the healthy eye model, while the models with softer or no extraocular tissue had lesser deformations, in both adduction and abduction. In healthy subjects, the mean tilt angle was 1.46°±0.25 in adduction and −0.42°±0.12 in abduction. The tilt angle measured in the subject with TED was 5.37° in adduction and −2.21° in abduction.ConclusionComputational modelling and experimental observation suggest that TED can cause increased gaze-evoked deformations of the ONH.

scholarly journals Optic Nerve Tortuosity and Globe Proptosis in Normal and Glaucoma Subjects

2018 ◽  
Author(s):  
Xiaofei Wang ◽  
Helmut Rumpel ◽  
Mani Baskaran ◽  
Tin A Tun ◽  
Nicholas Strouthidis ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Eye Movements ◽  
Optic Nerve ◽  
Magnetic Resonance ◽  
Optic Nerve Head ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Open Angle ◽  
Resonance Imaging ◽  
Optic Nerves

AbstractPurposeTo assess the difference in optic nerve tortuosity during eye movements and globe proptosis between primary open angle glaucoma and normal subjects using orbital magnetic resonance imaging.Methods10 Chinese subjects matched for age, ethnicity and refractive errors were recruited, including five normal controls and five patients with primary open angle glaucoma. All subjects underwent magnetic resonance imaging to assess their optic nerves and globes for three eye positions: primary gaze, adduction and abduction. Optic nerve tortuosity (optic nerve length divided by the distance between two ends) and globe proptosis (maximum distance between cornea and interzygomatic line) were measured from magnetic resonance imaging images.ResultsIn adduction, the tortuosity of normal eyes was significantly larger than that of the glaucomatous eyes. Optic nerve tortuosity in adduction in the control and glaucoma groups were 1.004±0.003 (mean ± standard deviation) and 1.001±0.001, respectively (p=0.037). Globe proptosis (primary gaze) in glaucoma subjects (19.14±2.11 mm) was significantly higher than that in control subjects (15.32±2.79 mm; p = 0.046).ConclusionsIn this sample, subjects with glaucoma exhibited more taut optic nerves and more protruding eye globes compared to normal eyes. This may impact optic nerve head deformations in anatomically predisposed patients.PrécisEyes with glaucoma have tauter optic nerves compared with normal eyes, which may exert more force on the optic nerve head tissues during eye movements.

scholarly journals A case of occult bilateral optic nerve aplasia with pituitary dysfunction: hidden anomaly missed on ultrasound

2020 ◽  
Vol 13 (2) ◽  
pp. e232839
Author(s):  
Harsha Saxena ◽  
Brijesh Takkar ◽  
Amber Kumar ◽  
Radha Sarawagi
Keyword(s):  
Eye Movements ◽  
Optic Nerve ◽  
Clinical Signs ◽  
Endocrine Disorders ◽  
Pituitary Dysfunction ◽  
Life Threatening

We report a case of ‘occult’ bilateral optic nerve aplasia (ONA) where pituitary dysfunction was discovered subsequently. The initial ultrasonography had missed ONA in a child with bilateral microcornea, small non-dilating pupils and roving eye movements. Due to presence of relevant clinical signs in this case, ONA was re-evaluated with MRI, and was subsequently discovered to be associated with life-endangering hypopituitarism. This case raises the possible underestimation of ONA, and hence also the risk of missing life-threatening endocrine disorders.

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