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Box plots of the shear moduli of the prelamina and the LC across diagnostic groups (Healthy, OHT, PACG, and POAG). P values derived from the Mann-Whitney-Wilcoxon tests are shown. (a) The shear moduli of the prelamina of healthy subjects were significantly lower than those of the OHT subjects. (b) There was no statistically significant difference in the extracted shear moduli of the LC across diagnostic groups.

Box plots of the shear moduli of the prelamina and the LC across diagnostic groups (Healthy, OHT, PACG, and POAG). P values derived from the Mann-Whitney-Wilcoxon tests are shown. (a) The shear moduli of the prelamina of healthy subjects were significantly lower than those of the OHT subjects. (b) There was no statistically significant difference in the extracted shear moduli of the LC across diagnostic groups.

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Article
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Purpose: To develop and use a custom virtual fields method (VFM) to assess the biomechanical properties of human prelamina and lamina cribrosa (LC) in vivo. Methods: Clinical data of 20 healthy, 20 ocular hypertensive (OHT), 20 primary open-angle glaucoma, and 16 primary angle-closure glaucoma eyes were analyzed. For each eye, the intraocular pr...

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Context 1
... extracted shear moduli of the prelamina were 56.0 ± 36.6 kPa for healthy subjects, 82.4 ± 40.1 kPa for OHT subjects, 57.5 ± 25.2 kPa for PACG subjects, and 62.3 ± 38.1 kPa for POAG subjects (Table 1). The shear moduli of the prelamina of healthy subjects were significantly lower than those of the OHT subjects (P = 0.019; Fig. ...
Context 2
... extracted shear moduli of the LC were 57.4 ± 42.8 kPa for healthy subjects, 79.2 ± 45.6 kPa for OHT subjects, 80.2 ± 50.5 kPa for PACG subjects, and 78.1 ± 50.4 for POAG subjects (Table 1; Fig. ...

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Background We aim to describe the short-term effect of femtosecond laser-assisted cataract surgery (FLACS) in intraocular pressure (IOP), visual acuity (VA), number of hypotensive medications, and visual fields (VF) in glaucomatous eyes.Methods Single-center consecutive case series study included patients with a previous glaucoma diagnosis that nee...

Citations

... Acute intraocular pressure (IOP) elevation through ocular compression is commonly used to study the biomechanical properties of the LC in glaucoma research. [6][7][8][9] Any morphological changes in the LC were monitored before and during ocular compression. Previous studies have measured the IOP immediately after ocular compression only. ...
... Investigators assumed IOP to be constant during ocular compression. 8,9 Our recent pilot study demonstrated an IOP drop during a 1-min ocular compression. IOP recovery after ocular compression took longer than 5 min (Lam, AKC & Xu, FY. ...
... Since high myopia is a risk factor for primary open-angle glaucoma (POAG), the evaluation of LC has important implications for understanding the correlation between high myopia and POAG. 10 It is inappropriate to assume a constant IOP when the LC is scanned using OCT during ocular compression, especially when OCT scanning lasts for ≥2 min. 9 In the current study, IOP was monitored during a 2-min ocular compression, and the IOP recovery phase was monitored after the release of the compressive force. We speculated that there was a continuous drop in IOP during ocular compression. ...
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Preprint
Introduction Recent studies have monitored lamina cribrosa deformation using optical coherence tomography during ocular compression. Intraocular pressure (IOP) was measured only once immediately after ocular compression. This study aimed to evaluate IOP changes during and after ocular compression and compare the differences between low and high myopia. Methods Two groups of young, healthy adults were age-matched and underwent ocular compression. IOP was measured at baseline and monitored during a 2-min ocular compression followed by a 10-min recovery phase. Rebound tonometry was used and applied at 30-s intervals. Results Thirty low and 30 high myopes (60 right eyes) were included in the study. They had similar baseline IOP at 14.9mmHg. The immediate IOP rise was 10.2mmHg and 10.3mmHg from baseline in each group, respectively. Low myopes had faster IOP decay during ocular compression at -3.24mmHg/min than high myopes at -2.58mmHg/min (p = 0.0528). The IOP dropped below the baseline level after the release of the compressive force. Low myopes had IOP that returned to baseline levels faster (at 360 s) than high myopes (at 510 s). Conclusion Measuring IOP once immediately after ocular compression could under-estimate the effect of IOP increase on lamina cribrosa deformation. The difference in IOP dynamics from ocular compression between low and high myopia may be used to reflect aqueous humour outflow facilities.
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... This approach was recently applied successfully in biaxial tension by Kazerooni et al [27] to identify the parameters of a Holzapfel model [28] for the skin. For other types of loading, for instance, Zhang et al. [23] introduced analytical expressions of virtual fields which were written in the cylindrical coordinate system using the arctan function. For inflation experiments, Bersi et al. [29] used virtual fields that permitted to derive local equilibrium equations relating the intraluminal pressure and the wall tensile stresses. ...
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