The height of the posterior staphyloma and corneal hysteresis is associated with the scleral thickness at the staphyloma region in highly myopic normal-tension glaucoma eyes

Park, Jong Hyuk; Choi, Kyu Ryong; Kim, Chan Yun; Kim, Sung Soo

doi:10.1136/bjophthalmol-2015-307292

Cited by 4 publications

(2 citation statements)

References 35 publications

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“…Scleral staphylomas are a feature of highly myopic eyes. They have been described as outpouchings of a circumscribed region of the posterior sclera [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. Scleral staphylomas show a relatively abrupt scleral thinning at the staphyloma edge; a pronounced de-arrangement of scleral collagen fibrils; a marked, segmentally accentuated, choroidal thinning, most marked at the staphyloma border; and spatially correlated BM defects.…”

Section: Resultsmentioning

confidence: 99%

Anatomic Peculiarities Associated with Axial Elongation of the Myopic Eye

Jonas

Бикбов

Wang

et al. 2023

JCM

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Purpose: To describe anatomical peculiarities associated with axial elongation in the human myopic eye. Methods: Reviewing the results of previous histomorphometrical investigations of enucleated human globes, as well as reviewing findings obtained in population-based studies and hospital-based clinical investigations of myopic patients and non-myopic individuals. Results: Myopic axial elongation is associated with a change from a mostly spherical eye shape to a prolate ellipsoid form. It is combined with choroidal and scleral thinning, most pronounced at the posterior pole and less pronounced in the fundus midperiphery. In the fundus midperiphery, the retina and density of the retinal pigment epithelium (RPE) and photoreceptors decrease with a longer axial length, while in the macular region, retinal thickness, RPE cell density, and choriocapillaris thickness are not related to axial length. With axial elongation, a parapapillary gamma zone develops, leading to an enlargement of the optic disc-fovea distance and a decrease in angle kappa. Axial elongation is also correlated with an increase in the surface and volume of Bruch’s membrane (BM), while BM thickness remains unchanged. Axial elongation causes moderately myopic eyes to show a shift of BM opening to the foveal direction so that the horizontal disc diameter becomes shorter (with a consequent vertical ovalization of the optic disc shape), a temporal gamma zone develops, and the optic nerve exit takes an oblique course. Features of high myopia are an enlargement of the RPE opening (myopic parapapillary beta zone) and BM opening (secondary macrodisc), elongation and thinning of the lamina cribrosa, peripapillary scleral flange (parapapillary delta zone) and peripapillary choroidal border tissue, secondary BM defects in the macular region, myopic maculoschisis, macular neovascularization, and cobblestones in the fundus periphery. Conclusions: These features combined may be explained by a growth in BM in the fundus midperiphery leading to axial elongation.

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Section: Resultsmentioning

confidence: 99%

Anatomic Peculiarities Associated with Axial Elongation of the Myopic Eye

Jonas

Бикбов

Wang

et al. 2023

JCM

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“…Previous studies showed that a lower CH in patients with glaucoma was associated with increased deformation of the optic nerve surface during transient IOP elevation; but such correlation was not observed in normal controls. 32 Others have reported a correlation between a lower CH and a thinner scleral thickness in individuals with high myopia 33 and a correlation between a lower corneal deformation amplitude and a larger lamina cribrosa (LC) depth in primary open-angle glaucoma. 34 Our study identified a correlation between the cornea and the ONH's shear response in ostensibly normal donor eyes with no known ocular diseases, indicating a possible presence of a biomechanical relationship between the cornea and the posterior eye likely due to innate structural correspondence.…”

Section: Discussionmentioning

confidence: 99%

Biomechanical Correlations Between the Cornea and the Optic Nerve Head

Pan,

Kwok,

Pan

et al. 2024

Invest. Ophthalmol. Vis. Sci.

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A thin cornea is a potent risk factor for glaucoma. The underlying mechanisms remain unexplained. It has been postulated that central corneal thickness (CCT) may be a surrogate for biomechanical parameters of the posterior eye. In this study, we aimed to explore correlations of biomechanical responses between the cornea and the optic nerve head (ONH) and the peripapillary sclera (PPS) to elevated intraocular pressure (IOP), the primary risk factor of glaucoma. METHODS.Inflation tests were performed in nine pairs of human donor globes. One eye of each pair was randomly assigned for cornea or posterior eye inflation. IOP was raised from 5 to 30 millimeters of mercury (mmHg) at 0.5 mmHg steps in the whole globe and the cornea or the ONH/PPS was imaged using a 50 MHz ultrasound probe. Correlationbased ultrasound speckle tracking was used to calculate tissue displacements and strains. Associations of radial, tangential, and shear strains at 30 mmHg between the cornea and the ONH or PPS were evaluated. RESULTS.Corneal shear strain was significantly correlated with ONH shear strain (R = 0.857, P = 0.003) and PPS shear strain (R = 0.724, P = 0.028). CCT was not correlated with any strains in the cornea, ONH, or PPS. CONCLUSIONS.Our results suggested that an eye that experiences a larger shear strain in the cornea would likely experience a larger shear strain in its ONH and PPS at IOP elevations. The strong correlation between the cornea's and the ONH's shear response to IOP provides new insights and suggests a plausible explanation of the cornea's connection to glaucoma risk.

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