Deformation of the Early Glaucomatous Monkey Optic Nerve Head Connective Tissue after Acute IOP Elevation in 3-D Histomorphometric Reconstructions

Yang, Hongli; Thompson, Hilary W.; Roberts, Michael D.; Sigal, Ian A.; Downs, J. Crawford; Burgoyne, Claude F.

doi:10.1167/iovs.09-5122

Cited by 117 publications

(134 citation statements)

References 71 publications

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“…Also, the results are not contradicted by the findings of Nicolela et al (2006), who did not find changes in the optic disc topography after moderate increases and decreases in intraocular pressure in the order of 5 mmHg, because our study included patients with a marked decrease in intraocular pressure. The finding of a decrease in optic disc size after a pronounced reduction in a markedly elevated intraocular pressure in patients with glaucoma may be similar to the enlargement of the optic disc in monkeys with experimental glaucoma (Yang et al 2011). Another new finding of our study was that some eyes can show marked changes in the appearance of beta zone of parapapillary atrophy after pronounced reduction in an elevated intraocular pressure (Figs 1 and 2).…”

Section: Introductionsupporting

confidence: 82%

Optic nerve head morphology in young patients after antiglaucomatous filtering surgery

Panda‐Jonas

Yang

et al. 2013

Acta Ophthalmologica

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. Purpose: To compare the optic nerve head appearance in glaucomatous eyes before and after marked reduction of intraocular pressure (IOP). Methods: The hospital‐based observational case‐series study included selected glaucoma patients for whom optic disc photographs taken before and 1 week to 5 months after surgical reduction of IOP were morphometrically examined. Results: The study included 23 eyes of 16 patients (mean age: 28.7 ± 6.0 years). Mean preoperative IOP was 31.6 ± 7.7 mmHg (22–52 mmHg), and mean IOP drop was 21.5 ± 8.4 mmHg (11–45 mmHg). The horizontal disc diameter decreased significantly (p < 0.001) after surgery, while the vertical disc diameter did not change markedly (p = 0.54). The width of the neuroretinal rim increased significantly in all disc quadrants (all p‐values ≤ 0.01), optic cup depth decreased (p < 0.001), and reflectivity of the inner retinal surface increased significantly (p < 0.001). Some eyes showed a pronounced reduction in beta zone of parapapillary atrophy parallel to an increase in horizontal disc diameter, and some eyes showed an enlargement of beta zone parallel to a reduction in horizontal disc diameter. Conclusions: After marked reduction of high IOP, some eyes of young adult patients with glaucoma can show a horizontal shrinkage of the optic nerve head, in addition to a partial restoration of the neuroretinal rim and a flattening of the optic cup. In addition, beta zone of parapapillary atrophy can decrease or increase, complementarily to changes in the horizontal disc diameter. These findings may be of interest for the biomechanics of the optic nerve head and the precision of imaging techniques.

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Section: Introductionsupporting

confidence: 82%

Optic nerve head morphology in young patients after antiglaucomatous filtering surgery

Panda‐Jonas

Yang

et al. 2013

Acta Ophthalmologica

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“…Peripapillary sclera has been extensively investigated, because it is known to play an important role in the deformation of lamina cribrosa [47]. Since the stiffness of the peripapillary sclera of glaucomatous eyes was different from that of normal eyes in the cases of experimental monkeys and postmortem humans [7][8][9][10], it is likely that the stiffness of the peripapillary sclera is related to the progression of glaucoma. In the future, it would be interesting to investigate birefringence of peripapillary sclera in normal and glaucomatous eyes using PS-OCT especially designed for posterior segment imaging [28,48,49].…”

Section: Discussionmentioning

confidence: 99%

“…IOP was monitored by a pressure sensor (MLT0699, ADInstruments, Bella Vista, NSW, Australia) that was located at the same height as the eye. The height of the liquid level was controlled manually to change the IOP of the eye from 5 to 60 mmHg with eight steps (5,10,14,18,22,30,45, and 60 mmHg). Birefringence of the porcine sclera was measured at each controlled IOP using the PS-OCT. Figure 3 shows representative OCT intensity and local birefringence images.…”

Section: Inflation Response Of Ex Vivo Porcine Scleramentioning

confidence: 99%

“…Although the alignment of scleral collagen fibers in glaucomatous eyes is not known well, Pijanka et al reported that sclerae of some glaucomatous eyes had decreased fiber anisotropy of collagen fibers in two quadrant sectors around the optic nerve head [6]. The stiffness of the peripapillary sclera of glaucomatous eyes was different from that of normal eyes in the cases of experimental monkeys and postmortem humans [7][8][9][10]. Glaucomatous human eyes had lower density of collagen fibers in peripapillary sclera than that of normal human eyes [11].…”

Section: Introductionmentioning

confidence: 99%

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Scleral birefringence as measured by polarization-sensitive optical coherence tomography and ocular biometric parameters of human eyes in vivo

Yamanari

Nagase

Fukuda

et al. 2014

Biomed. Opt. Express

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Abstract:The relationship between scleral birefringence and biometric parameters of human eyes in vivo is investigated. Scleral birefringence near the limbus of 21 healthy human eyes was measured using polarizationsensitive optical coherence tomography. Spherical equivalent refractive error, axial eye length, and intraocular pressure (IOP) were measured in all subjects. IOP and scleral birefringence of human eyes in vivo was found to have statistically significant correlations (r = −0.63, P = 0.002). The slope of linear regression was −2.4 × 10 −2 deg/μm/mmHg. Neither spherical equivalent refractive error nor axial eye length had significant correlations with scleral birefringence. To evaluate the direct influence of IOP to scleral birefringence, scleral birefringence of 16 ex vivo porcine eyes was measured under controlled IOP of 5−60 mmHg. In these ex vivo porcine eyes, the mean linear regression slope between controlled IOP and scleral birefringence was −9.9 × 10 −4 deg/μm/mmHg. In addition, porcine scleral collagen fibers were observed with second-harmonic-generation (SHG) microscopy. SHG images of porcine sclera, measured on the external surface at the superior side to the cornea, showed highly aligned collagen fibers parallel to the limbus. In conclusion, scleral birefringence of healthy human eyes was correlated with IOP, indicating that the ultrastructure of scleral collagen was correlated with IOP. It remains to show whether scleral collagen ultrastructure of human eyes is affected by IOP as a long-term effect. ©2014 Optical Society of America References and links1. N. A. McBrien and A. Gentle, "Role of the sclera in the development and pathological complications of myopia," Prog. Retin. Eye Res. 22(3), 307-338 (2003). 2. C. F. Burgoyne, J. C. Downs, A. J. Bellezza, J. K. Suh, and R. T. Hart, "The optic nerve head as a biomechanical structure: a new paradigm for understanding the role of IOP-related stress and strain in the pathophysiology of glaucomatous optic nerve head damage," Prog. Retin. Eye Res. 24(1), 39-73 (2005). 3. J. A. Rada, S. Shelton, and T. T. Norton, "The sclera and myopia," Exp. Eye Res. 82(2), 185-200 (2006). 4. J. T. Siegwart, Jr. and T. T. Norton, "Regulation of the mechanical properties of tree shrew sclera by the visual environment," Vision Res. 39(2), 387-407 (1999 1714-1728 (2012) C. So, and C.-Y. Dong, "Multiphoton autofluorescence and second-harmonic generation imaging of the ex vivo porcine eye," Invest.

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“…[1][2][3][4][5][6][7] Under the biomechanical paradigm for glaucoma pathogenesis, the influence of increased intraocular pressure (IOP) on the LC has been widely elucidated in experimental glaucoma animal models. [7][8][9][10][11][12] Early experimental glaucoma monkey eyes, for example, showed posterior migration of anterior and posterior laminar insertion. 12 Posterior displacement of laminar insertion has been confirmed in autopsied and enucleated human eyes with advanced glaucoma.…”

Section: Introductionmentioning

confidence: 99%

Peripheral lamina cribrosa depth in primary open-angle glaucoma: a swept-source optical coherence tomography study of lamina cribrosa

Kim

Jeoung

et al. 2015

Eye

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Purpose To investigate peripheral lamina cribrosa depth (PLCD) and its verticalhorizontal difference in eyes with primary open-angle glaucoma (POAG). Methods Patients with POAG (n = 90 eyes) and age-matched healthy individuals (n = 90 eyes) underwent swept-source optical coherence tomography (SS-OCT) scans centered at the optic discs. The PLCD was defined as the vertical distance between the most peripheral visible end of anterior lamina cribrosa (LC) surface and the reference plane connecting the Bruch's membrane openings. The PLCD in each quadrant region and the vertical-horizontal PLCD difference were compared between the POAG and healthy eyes. The clinical factors associated with increased PLCD were evaluated. Results The PLCD was significantly larger in the POAG eyes than the control eyes at the horizontal (P = 0.034) and vertical (P = 0.001) meridians. The vertical PLCD was significantly larger than the horizontal PLCD, both in the POAG eyes (Po0.001) and in the control eyes (P = 0.003). However, the vertical-horizontal PLCD difference was significantly larger in the POAG eyes (47 ± 60 μm) than in the control eyes (18 ± 54 μm, P = 0.001). Multivariate regression showed a significant association of male gender (P = 0.005), increased baseline IOP (P = 0.043), and decreased MD of VF (P = 0.025) with increased PLCD. Conclusions The peripheral LC was displaced more posteriorly in the POAG eyes compared with the age-matched healthy eyes. In the POAG eyes, the peripheral LC was displaced more posteriorly at the vertical meridian than at the horizontal meridian. The peripheral LC in the vertical meridian might have increased IOP-related strain (deformation) compared with horizontal meridian in glaucomatous eyes.

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Deformation of the Early Glaucomatous Monkey Optic Nerve Head Connective Tissue after Acute IOP Elevation in 3-D Histomorphometric Reconstructions

Abstract: The data suggest that, in monkey EEG, ONH connective tissue hypercompliance may occur only in a subset of eyes and that early ONH connective tissue deformation is maximized in the superior temporal and/or inferior nasal quadrants.

Cited by 117 publications

References 71 publications

Optic nerve head morphology in young patients after antiglaucomatous filtering surgery

Optic nerve head morphology in young patients after antiglaucomatous filtering surgery

Scleral birefringence as measured by polarization-sensitive optical coherence tomography and ocular biometric parameters of human eyes in vivo

Peripheral lamina cribrosa depth in primary open-angle glaucoma: a swept-source optical coherence tomography study of lamina cribrosa

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