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Ehongo A, Bacq N, Kisma N, Dugauquier A, Alaoui Mhammedi Y, Coppens K, Bremer F, Leroy K. Analysis of Peripapillary Intrachoroidal Cavitation and Myopic Peripapillary Distortions in Polar Regions by Optical Coherence Tomography. Clin Ophthalmol 2022; 16:2617-2629. [PMID: 35992567 PMCID: PMC9387167 DOI: 10.2147/opth.s376597] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 08/04/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose To compare the peripapillary polar characteristics in eyes combining peripapillary staphyloma and gamma peripapillary atrophy according to whether peripapillary intrachoroidal cavitation (PICC) was present or absent (combination-group). Patients and methods This prospective non-interventional cross-sectional study included 667 eyes of 334 subjects. From the polar peripapillary regions to the opening of Bruch’s membrane, the following elements and their topographic relationships were analyzed using optical coherence tomography sections: configuration of the posterior curvature of the choroid, visibility of the subarachnoid space (SAS), and suprachoroidal detachment (SCD). Chi-squared and Fisher exact tests were used for statistical analysis. Results The protrusion of the posterior choroidal wall, with anterior elevation on either side, observed in both groups progressed and transformed into a wedge-shaped deformity on the side of gamma peripapillary atrophy. This wedge configuration was significantly more frequent in PICC-group than in combination-group (p = 0.004 and p < 0.001) for the upper and lower poles, respectively. SAS was more frequently observed in PICC-group than in combination-group (p = 0.002 and p < 0.001) for the upper and lower poles, respectively. SCD was detected exclusively in PICC-group (p < 0.001, both poles). The wedge-shaped configuration and the SCD were aligned antero-posteriorly with the SAS. Conclusion We confirmed that PICC is an SCD. We observed its constant alignment with the SAS. We suggest that the tensile forces of the optic nerve sheaths during adduction promote the collapse of the scleral flange onto the SAS, leading to PICC. Further studies are warranted to confirm this hypothesis.
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Affiliation(s)
- Adèle Ehongo
- Ophthalmology Department, Erasmus Hospital, Brussels, 1070, Belgium
- Correspondence: Adèle Ehongo, Ophthalmology Department, Erasmus Hospital, Route de Lennik 808, Brussels, 1070, Belgium, Tel +3225553114, Fax +3225556737, Email
| | - Noélie Bacq
- Ophthalmology Department, Erasmus Hospital, Brussels, 1070, Belgium
| | - Nacima Kisma
- Ophthalmology Department, Erasmus Hospital, Brussels, 1070, Belgium
| | | | | | - Kevin Coppens
- Statistician, Cosma Consulting, Enghien7850, Belgium
| | - Françoise Bremer
- Ophthalmology Department, Erasmus Hospital, Brussels, 1070, Belgium
| | - Karelle Leroy
- Histology Department, Erasmus Campus, CP 620, Université Libre de Bruxelles, Brussels, 1070, Belgium
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Cho KH, Takahashi A, Yamamoto M, Hirouchi H, Taniguchi S, Ogawa Y, Murakami G, Abe SI. Optic nerve-associated connective tissue structures revisited: a histological study using human fetuses and adult cadavers. Anat Rec (Hoboken) 2022; 305:3516-3531. [PMID: 35358354 DOI: 10.1002/ar.24925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 11/10/2022]
Abstract
Unlike the usual peripheral nerve, the optic nerve accompanies a thick "dural sheath," a thin "sheath of pia mater" (SPM), and multiple "septa," which divides the nerve fibers into fascicles. We collected specimens from 25 adult cadavers and 15 fetuses and revisited the histological architecture of the optic and oculomotor nerves. In the optic chiasma, the meningeal layer of the dura joins the pia to form a thick SPM, and the periosteum of the sphenoid is continuous with the dural sheath at the orbital exit of the bony optic canal. The septa appeared as a cluster of irregularly arrayed fibrous plates in the intracranial course near the chiasma. Thus, the septa were not derived from either the SPM or the dural sheath. In the orbit, the central artery of the retina accompanies collagenous fibers from the dural sheath and the SPM to provide the vascular sheath in the optic nerve. These connective tissue configurations were the same between adult and fetal specimens. At the optic disk, the dural sheath and SPM merged with the sclera, whereas the septa appeared to end at the lamina cribrosa. However, in fetuses without lamina cribrosa, the septa extend into the nerve fiber layer of the retina. The SPM and septa showed strong elastin immunoreactivity, in contrast to the absence of reactivity in the sheaths of the oculomotor nerve. Each S100 protein-positive Schwann sheath of the oculomotor nerve was surrounded by collagenous endoneurium. Glial fibrillary acidic protein-positive astrocytes showed a linear arrangement along the septa. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Kwang Ho Cho
- Department of Neurology, Wonkwang University School of Medicine and Hospital, Institute of Wonkwang Medical Science, 895, Muwang-ro, Iksan-si, Jeollabuk-do, Republic of Korea
| | | | | | | | | | - Yudai Ogawa
- Department of Histology and Developmental Biology, Tokyo Dental College, Tokyo, Japan
| | - Gen Murakami
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan.,Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan
| | - Shin-Ichi Abe
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
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Material properties and effect of preconditioning of human sclera, optic nerve, and optic nerve sheath. Biomech Model Mechanobiol 2021; 20:1353-1363. [PMID: 33877503 PMCID: PMC8298341 DOI: 10.1007/s10237-021-01448-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/06/2021] [Indexed: 02/03/2023]
Abstract
The optic nerve (ON) is a recently recognized tractional load on the eye during larger horizontal eye rotations. In order to understand the mechanical behavior of the eye during adduction, it is necessary to characterize material properties of the sclera, ON, and in particular its sheath. We performed tensile loading of specimens taken from fresh postmortem human eyes to characterize the range of variation in their biomechanical properties and determine the effect of preconditioning. We fitted reduced polynomial hyperelastic models to represent the nonlinear tensile behavior of the anterior, equatorial, posterior, and peripapillary sclera, as well as the ON and its sheath. For comparison, we analyzed tangent moduli in low and high strain regions to represent stiffness. Scleral stiffness generally decreased from anterior to posterior ocular regions. The ON had the lowest tangent modulus, but was surrounded by a much stiffer sheath. The low-strain hyperelastic behaviors of adjacent anatomical regions of the ON, ON sheath, and posterior sclera were similar as appropriate to avoid discontinuities at their boundaries. Regional stiffnesses within individual eyes were moderately correlated, implying that mechanical properties in one region of an eye do not reliably reflect properties of another region of that eye, and that potentially pathological combinations could occur in an eye if regional properties are discrepant. Preconditioning modestly stiffened ocular tissues, except peripapillary sclera that softened. The nonlinear mechanical behavior of posterior ocular tissues permits their stresses to match closely at low strains, although progressively increasing strain causes particularly great stress in the peripapillary region.
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Ebihara S, Machida S, Hara Y, Tada A, Ishizuka M, Gonmori M, Nishimura T. Relationships between the vascular structure and neural function of the macula in patients with diabetes mellitus. Jpn J Ophthalmol 2020; 65:77-88. [PMID: 33174127 DOI: 10.1007/s10384-020-00784-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/23/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine the significance of the correlation between the vascular structure and neural function of the macula in patients with diabetes mellitus. STUDY DESIGN Single-center observational study. PATIENTS AND METHODS Ninety eyes of 90 diabetic patients with an average (SD) age of 63.5 (3.8) years were studied. Fifty of the eyes had no clinically apparent diabetic retinopathy (non-DR), and 40 eyes had mild-to-moderate nonproliferative DR (NPDR). Thirty age-matched healthy individuals were also studied in the same way. Swept-source optical coherence tomography angiography (OCTA) was performed to obtain 3 × 3-mm en face images of the posterior pole of the eye. The vascular densities (VDs) of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) were determined. The focal macular electroretinograms (ERGs) elicited by a 15° circular stimulus centered on the fovea were recorded. The amplitudes of the a- and b-waves, sum of the oscillatory potentials (ΣOPs), photopic negative response (PhNR), and implicit times of the individual OPs (OP1-OP3) were measured. RESULTS The VDs of the SCP and DCP were reduced in eyes with advanced DR (P < .01 for SCP). The implicit times of OP1-OP3 were significantly prolonged in eyes with a lower VD of the SCP and DCP in the non-DR group (P < .05). The amplitudes of the ΣOPs were significantly smaller in eyes with a reduced VD of the SCP and DCP in the NPDR group (P < .05). The correlation coefficients were higher for the OP implicit times than for the ΣOP amplitudes in the non-DR group. CONCLUSIONS The OPs of the focal macular ERG are smaller with prolonged implicit times in association with capillary loss in the macula of diabetic patients. The implicit times are the most sensitive functional parameter that reflects the early changes of the microvasculature in the macula caused by diabetes.
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Affiliation(s)
- Satoshi Ebihara
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan
| | - Shigeki Machida
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan.
| | - Yuji Hara
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan
| | - Atsushi Tada
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan
| | - Masahiko Ishizuka
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan
| | - Mana Gonmori
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan
| | - Tomoharu Nishimura
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan
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Lee C, Rohr J, Sass A, Sater S, Zahid A, Macias B, Stenger MB, Samuels BC, Martin BA, Oshinski JN, Ethier CR. In vivo estimation of optic nerve sheath stiffness using noninvasive MRI measurements and finite element modeling. J Mech Behav Biomed Mater 2020; 110:103924. [PMID: 32957219 DOI: 10.1016/j.jmbbm.2020.103924] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 12/21/2022]
Abstract
The optic nerve sheath (ONS) is biomechanically important. It is acted on by tension due to ocular movements, and by fluid shifts and/or alterations in intracranial pressure (ICP) in human disease, specifically in pathologies leading to intracranial hypertension. It has also been hypothesized that the ONS is acted on by altered ICP in astronauts exposed chronically to microgravity. However, a non-invasive method to quantify ONS biomechanical properties is not presently available; knowledge of such properties is desirable to allow characterization of the biomechanical forces exerted on the optic nerve head and other ocular structures due to the ONS. Thus, the primary objective of this study was to characterize the biomechanical properties (stiffness) of the human ONS in vivo as a necessary step towards investigating the role of ICP in various conditions, including Spaceflight Associated Neuro-ocular Syndrome (SANS). We acquired non-invasive magnetic resonance imaging (MRI) scans of ostensibly healthy subjects (n = 18, age = 30.4 ± 11.6 [mean ± SD] years) during supine and 15-degree head-down-tilt (HDT) postures, and extracted ONS contours from these scans. We then used finite element modeling to quantify ONS expansion due to postural changes and an inverse approach to estimate ONS stiffness. Using this non-invasive procedure, we estimated an in vivo ONS stiffness of 39.2 ± 21.9 kPa (mean ± SD), although a small subset of individuals had very stiff ONS that precluded accurate estimates of their stiffness values. ONS stiffness was not correlated with age and was higher in males than females.
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Affiliation(s)
- Chanyoung Lee
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Jesse Rohr
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Austin Sass
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Stuart Sater
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Arslan Zahid
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Brandon Macias
- Cardiovascular and Vision Laboratory, KBR, Houston, TX, USA
| | | | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bryn A Martin
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - John N Oshinski
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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Abstract
The article continues the anatomical review of the anterolateral myofascial connections of the five diaphragms in osteopathic manipulative medicine (OMM), with the most up-to-date scientific information. The postero-lateral myofascial relationships have been illustrated previously in the first part. The article emphasizes some key OMM concepts; the attention of the clinician must not stop at the symptom or local pain but, rather, verify where the cause that leads to the symptom arises, thanks to the myofascial systems. Furthermore, it is important to remember that the human body is a unity and we should observe the patient not as a series of disconnected segments but as multiple and different elements that work in unison; a dysfunction of tissue will adversely affect neighboring and distant tissues. The goal of the work is to lay solid foundations for the OMM and the five-diaphragm approach showing the myofascial continuity of the human body.
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Affiliation(s)
- Bruno Bordoni
- Physical Medicine and Rehabilitation, Foundation Don Carlo Gnocchi, Milan, ITA
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