Scanning Laser Ophthalmoscopy Demonstrates Disc and Peripapillary Strain During Horizontal Eye Rotation in Adults

Park, Joseph; Moon, Sung-Hyuk; Lim, Seongjin; Demer, Joseph L.

doi:10.1016/j.ajo.2023.06.008

Cited by 3 publications

(3 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, at the external surface, the ON sheath radius is much larger at 2.85-3.65 mm (Table 1) than the roughly 0.75 mm radius of the optic disc internal to the eye. In fact, deformations of the disc, peripapillary vessels, and choroid observed intraocularly by cSLO [8,9] and OCT [3][4][5] during horizontal duction occur largely within the region covered on the exterior surface by the ON sheath, and so are invisible to the current external imaging technique. This internal region, which includes the lamina cribrosa, is the site of ON damage in POAG, the world's largest cause of untreatable blindness [47,48].…”

Section: Discussionmentioning

confidence: 99%

“…Further, OCT studies quantified relative displacements [4], tilting [5], local area changes [6], and shear strains [7] in the optic disc during horizontal duction. In addition to horizontal duction-related anteroposterior deformations, in-plane deformations within the retina have also been investigated using confocal scanning laser ophthalmoscopy (cSLO) [8,9]. Angiographic OCT has demonstrated that adduction is associated with disc and vascular Bioengineering 2024, 11, 452 2 of 20 strains much larger than those reported for IOP elevation and pulsatile perfusion, and adduction also causes optic disc compression and an increase in peripapillary vascular volume [10].…”

Section: Introductionmentioning

confidence: 99%

“…The current study was performed to further investigate potentials for adduction tethering to load the posterior human sclera. Extensive in vivo MRI [22][23][24] and posterior intraocular imaging [5,[8][9][10][11]25,26] data exist demonstrating effects of incremental adduction from the average threshold of ON tethering at 26 • , by an additional 6 • to 32 • adduction, a practical experimental maximum for humans. These imaging studies provide high resolution of a limited area of internal ocular structures, and for MRI low resolution of the entire globe and a wide range of orbital structures.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Postmortem Digital Image Correlation and Finite Element Modeling Demonstrate Posterior Scleral Deformations during Optic Nerve Adduction Tethering

Lim,

Kim,

Jafari

et al. 2024

Bioengineering

Self Cite

View full text Add to dashboard Cite

Postmortem human eyes were subjected to optic nerve (ON) traction in adduction and elevated intraocular pressure (IOP) to investigate scleral surface deformations. We incrementally adducted 11 eyes (age 74.1 ± 9.3 years, standard deviation) from 26° to 32° under normal IOP, during imaging of the posterior globe, for analysis by three-dimensional digital image correlation (3D-DIC). In the same eyes, we performed uniaxial tensile testing in multiple regions of the sclera, ON, and ON sheath. Based on individual measurements, we analyzed eye-specific finite element models (FEMs) simulating adduction and IOP loading. Analysis of 3D-DIC showed that the nasal sclera up to 1 mm from the sheath border was significantly compressed during adduction. IOP elevation from 15 to 30 mmHg induced strains less than did adduction. Tensile testing demonstrated ON sheath stiffening above 3.4% strain, which was incorporated in FEMs of adduction tethering that was quantitatively consistent with changes in scleral deformation from 3D-DIC. Simulated IOP elevation to 30 mmHg did not induce scleral surface strains outside the ON sheath. ON tethering in incremental adduction from 26° to 32° compressed the nasal and stretched the temporal sclera adjacent to the ON sheath, more so than IOP elevation. The effect of ON tethering is influenced by strain stiffening of the ON sheath.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Postmortem Digital Image Correlation and Finite Element Modeling Demonstrate Posterior Scleral Deformations during Optic Nerve Adduction Tethering

Lim,

Kim,

Jafari

et al. 2024

Bioengineering

Self Cite

View full text Add to dashboard Cite

show abstract

Tensile properties of glaucomatous human sclera, optic nerve, and optic nerve sheath

Park,

Lee,

Jafari

et al. 2024

Biomech Model Mechanobiol

View full text Add to dashboard Cite

We characterized the tensile behavior of sclera, optic nerve (ON), and ON sheath in eyes from donors with glaucoma, for comparison with published data without glaucoma. Twelve freshly harvested eyes were obtained from donors with history of glaucoma, of average age 86 ± 7 (standard deviation) years. Rectangular samples were taken from anterior, equatorial, posterior, and peripapillary sclera, and ON sheath, while ON was in native form and measured using calipers. Under physiological temperature and humidity, tissues were preconditioned at 5% strain before loading at 0.1 mm/s. Force–displacement data were converted into engineering stress–strain curves fit by reduced polynomial hyperelastic models and analyzed by tangent moduli at 3% and 7% strain. Data were compared with an age-matched sample of 7 published control eyes. Optic atrophy was supported by significant reduction in ON cross section to 73% of normal in glaucomatous eyes. Glaucomatous was significantly stiffer than control in equatorial and peripapillary regions (P < 0.001). However, glaucomatous ON and sheath were significantly less stiff than control, particularly at low strain (P < 0.001). Hyperelastic models were well fit to stress–strain data (R2 > 0.997). Tangent moduli had variability similar to control in most regions, but was abnormally large in peripapillary sclera. Tensile properties were varied independently among various regions of the same eyes. Glaucomatous sclera is abnormally stiff, but the ON and sheath are abnormally compliant. These abnormalities correspond to properties predicted by finite element analysis to transfer potentially pathologic stress to the vulnerable disk and lamina cribrosa region during adduction eye movement.

show abstract

Scanning Laser Ophthalmoscopy Demonstrates Pediatric Optic Disc and Peripapillary Strain During Horizontal Eye Rotation

Moon,

Park,

Lim

et al. 2024

Current Eye Research

View full text Add to dashboard Cite

Scanning Laser Ophthalmoscopy Demonstrates Disc and Peripapillary Strain During Horizontal Eye Rotation in Adults

Cited by 3 publications

References 49 publications

Postmortem Digital Image Correlation and Finite Element Modeling Demonstrate Posterior Scleral Deformations during Optic Nerve Adduction Tethering

Postmortem Digital Image Correlation and Finite Element Modeling Demonstrate Posterior Scleral Deformations during Optic Nerve Adduction Tethering

Tensile properties of glaucomatous human sclera, optic nerve, and optic nerve sheath

Scanning Laser Ophthalmoscopy Demonstrates Pediatric Optic Disc and Peripapillary Strain During Horizontal Eye Rotation

Contact Info

Product

Resources

About