scholarly journals 3-D Histomorphometry of the Normal and Early Glaucomatous Monkey Optic Nerve Head: Lamina Cribrosa and Peripapillary Scleral Position and Thickness

2007 ◽  
Vol 48 (10) ◽  
pp. 4597 ◽  
Author(s):  
Hongli Yang ◽  
J. Crawford Downs ◽  
Christopher Girkin ◽  
Lisandro Sakata ◽  
Anthony Bellezza ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Lamina Cribrosa

scholarly journals Bruch’s membrane opening enlargement and its implication on the myopic optic nerve head

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mi Sun Sung ◽  
Min Young Heo ◽  
Hwan Heo ◽  
Sang Woo Park
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Lamina Cribrosa ◽  
Cross Sectional Study ◽  
Multivariate Regression Model ◽  
Bruch's Membrane ◽  
Bruch’S Membrane ◽  
Cross Sectional ◽  
Bruch’S Membrane Opening ◽  
Parapapillary Atrophy

AbstractWe examined the association between Bruch’s membrane opening (BMO) area and various ocular parameters and investigated the implication of BMO enlargement on the myopic optic nerve head. One hundred eighty-five myopic eyes were included in this cross-sectional study. Among the included eyes, 53 having axial lengths between 26 and 27 mm were further analyzed to investigate the association between BMO area and various ocular parameters. BMO area, BMO-minimum rim width (BMO-MRW), peripapillary choroidal thickness (pCT), width of β-parapapillary atrophy with and without Bruch’s membrane (PPA+BM and PPA−BM), and presence of lamina cribrosa (LC) defect were evaluated. We found that BMO area tended to increase with increasing axial length, but varied among the highly myopic eyes even though they had similar degrees of myopia. In the subgroup analysis of eyes with axial lengths between 26 and 27 mm, BMO area was highly variable and it significantly correlated with PPA−BM width and temporal-inferior, nasal-inferior, and nasal BMO-MRW and pCT. LC defects were more common in myopic eyes with enlarged BMO. A multivariate regression model revealed that higher intraocular pressure, enlarged BMO, and thinner BMO-MRW were associated with LC defects in highly myopic eyes. These findings should be considered when evaluating myopic eyes.

scholarly journals Longitudinal assessment of optic nerve head changes using optical coherence tomography in a primate microbead model of ocular hypertension

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anita S. Y. Chan ◽  
Tin Aung Tun ◽  
John C. Allen ◽  
Myoe Naing Lynn ◽  
Sai Bo Bo Tun ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Ocular Hypertension ◽  
Optic Nerve Head ◽  
Structural Damage ◽  
Structural Changes ◽  
Lamina Cribrosa ◽  
Optical Coherence ◽  
Longitudinal Assessment ◽  
The Mean

Abstract In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.

scholarly journals A poroelastic model for the perfusion of the lamina cribrosa in the optic nerve head

2014 ◽  
Vol 257 ◽  
pp. 33-41 ◽  
Author(s):  
Paola Causin ◽  
Giovanna Guidoboni ◽  
Alon Harris ◽  
Daniele Prada ◽  
Riccardo Sacco ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Lamina Cribrosa ◽  
Poroelastic Model

scholarly journals In Vivo Changes in Lamina Cribrosa Microarchitecture and Optic Nerve Head Structure in Early Experimental Glaucoma

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0134223 ◽  
Author(s):  
Kevin M. Ivers ◽  
Nripun Sredar ◽  
Nimesh B. Patel ◽  
Lakshmi Rajagopalan ◽  
Hope M. Queener ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Lamina Cribrosa ◽  
Experimental Glaucoma

Interactions Between Factors Influencing Optic Nerve Head Biomechanics

2007 ◽  
Author(s):  
Ian A. Sigal ◽  
John G. Flanagan ◽  
C. Ross Ethier
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Mechanical Response ◽  
Ganglion Cells ◽  
Cell Damage ◽  
Mechanical Strain ◽  
Lamina Cribrosa ◽  
Retinal Ganglion ◽  
The Finite Element Method ◽  
Primary Risk Factor

Glaucoma is the second most common cause of blindness worldwide, and elevated intraocular pressure (IOP) is the primary risk factor for developing this disease. It has been postulated that IOP-induced mechanical strain on optic nerve head (ONH) glial cells leads to retinal ganglion cell damage and the consequent loss of vision in glaucoma. To better evaluate this theory it is important to understand the biomechanical environment within the ONH. Unfortunately it is very difficult to make measurements in the ONH, and it is particularly difficult to access the region in the ONH where the ganglion cells are thought to be injured, namely the lamina cribrosa. We have therefore developed models of the ONH and used the finite element method (FEM) to predict ONH mechanical response to changes in IOP [1].

scholarly journals Image-Based Modeling of Optic Nerve Head Mechanics Following Lumbar Puncture

2017 ◽  
Author(s):  
Junfei Tong ◽  
Deepta Ghate ◽  
Sachin Kedar ◽  
Linxia Gu
Keyword(s):  
Optic Nerve ◽  
Lumbar Puncture ◽  
Optic Nerve Head ◽  
Computational Models ◽  
Cell Damage ◽  
Open Angle Glaucoma ◽  
Element Model ◽  
Lamina Cribrosa ◽  
Image Based Modeling

Biomechanics of optic nerve head (ONH) has attracted increasing attention in recent years due to its association with ganglion cell damage and tissue remodeling resulted vision impairments [1, 2]. The ONH is exposed to both intraocular pressure (IOP) and intracranial pressure (ICP), separated by the lamina cribrosa (LC) which is regarded as the primary site of axonal injury in glaucoma[3]. The elevated IOP was widely acknowledged as a major risk factor for glaucoma. However, a large number of glaucoma patients never have an increase in IOP [4]. In studies that have looked at lumbar puncture (LP) data, patients with open-angle glaucoma were found to have lower ICPs than non-glaucomatous controls[5]. It suggests that higher translaminar pressure difference across the LC rather than IOP alone may have an important role in the pathogenesis of ONH damage. There were few computational models had been established to investigate the ICP’s role on ONH, such as Ethier et al. found elevated ICP could induce decreased strain within LC using finite element model[6]. However, less experimental data are available for delineating the role of ICP on the behaviors of LC. In this work, we present one dataset from LP patients and reconstruct its two-dimensional computational model of the ONH based on the patient’s images to delineate the role of ICP on ONH mechanics. The changes of LC depth, BMO width and papillary height were compared between the simulation and clinical dataset. The maximum principal strain of LC was calculated to reinforce its link with mechanosensitive cells in ONH.

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