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Yang Q, Lv S, Zhu H, Zhang L, Li H, Song S. A Potential Research Target for Scleral Remodeling: Effect of MiR-29a on Scleral Fibroblasts. Ophthalmic Res 2022; 65:566-574. [PMID: 35605595 DOI: 10.1159/000525189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 05/06/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The purpose of this study was to determine whether miR-29a regulates cell survival and apoptosis and the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), MMP-2, and collagen I in scleral fibroblasts. METHODS We transfected scleral fibroblasts with the miR-29a mimic and inhibitor. The effects of miR-29a on cell proliferation and apoptosis were determined using the CCK-8 assay and flow cytometry, respectively. Quantitative polymerase chain reaction (qPCR) was used to determine whether miR-29a regulates the mRNA levels of PTEN, MMP-2, and collagen I. The protein expression of PTEN, MMP-2, and collagen I was also assessed by western blot analysis. RESULTS The results of CCK-8 showed that, at 0, 24, 48, and 72 h after transfection, the relative optical density values in the mimic group were 0.233 ± 0.005, 0.380 ± 0.008, 0.650 ± 0.040, and 0.906 ± 0.032, and in the inhibitor group were 0.272 ± 0.011, 0.393 ± 0.029, 0.597 ± 0.059, and 0.950 ± 0.101, respectively. The flow cytometry results showed that the apoptosis rates of each group were as follows: the mimic group (0.043 ± 0.007), the NC group (0.040 ± 0.006), the inhibitor group (0.032 ± 0.003), the inhibitor NC group (0.027 ± 0.010), the lipofectamine group (0.027 ± 0.005), and the blank group (0.031 ± 0.009). The qPCR results indicated that in the mimic group, PTEN (0.795 ± 0.182, p = 0.2783), MMP-2 (0.621 ± 0.105, p = 0.0033), and COL1A1 (0.271 ± 0.100, p = 0.0002) expression decreased, whereas in the inhibitor group, PTEN (1.211 ± 0.100, p = 0.2614), MMP-2 (1.161 ± 0.053, p = 0.1190), and COL1A1 (1.7040 ± 0.093, p = 0.0003) increased. Western blot analysis showed that in the mimic group, the expression of PTEN (0.392 ± 0.039, p < 0.0001), MMP-2 (0.577 ± 0.017, p < 0.0001), and COL1A1 (0.072 ± 0.006, p < 0.0001) protein decreased, whereas in the inhibitor group, PTEN (1.043 ± 0.042, p = 0.9413), MMP-2 (1.397 ± 0.075, p = 0.0002), and COL1A1 (1.935 ± 0.081, p < 0.0001) expression increased. CONCLUSION MiR-29a inhibits the expression of PTEN, MMP-2, and collagen I on scleral fibroblasts, which may provide a basis studies in sclera.
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Affiliation(s)
- Qianying Yang
- Department of Ophthalmology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China,
| | - Sha Lv
- Department of Ophthalmology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
| | - Huirong Zhu
- Department of Ophthalmology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
| | - Liming Zhang
- Department of Ophthalmology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
| | - Hua Li
- Department of Ophthalmology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
| | - Shengfang Song
- Department of Ophthalmology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China
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Platzl C, Kaser-Eichberger A, Benavente-Perez A, Schroedl F. The choroid-sclera interface: An ultrastructural study. Heliyon 2022; 8:e09408. [PMID: 35586330 PMCID: PMC9108890 DOI: 10.1016/j.heliyon.2022.e09408] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/29/2021] [Accepted: 05/05/2022] [Indexed: 11/27/2022] Open
Abstract
Emmetropization is an active and visually guided process that involves the retina, choroid and sclera, and results in compensatory changes in eye growth. This guided growth is the result of visual cues and possibly mechanical interactions being translated into growth signals via molecular events from the retina into the choroid and sclera, through the choroidal scleral transition zone. If mechanical interactions were a part of the choroid-sclera signaling transduction cascade, specific morphological arrangements should be detectable in this region at the ultrastructural level. The goal of this study was to investigate the ultrastructural features of the choroidal scleral transition zone by comparing avian, non-human primate and human eyes, with the goal to confirm whether specific mechanical structures are present. Choroidal and scleral tissue from chicken, marmoset, and human eyes were imaged using transmission electron microscopy to document the choroid-sclera transition zone. In chicken eyes, fibroblast lamellae bordered the scleral matrix and formed thin end elongated processes that were undercut by scleral collagen fibrils. These processes back-looped into the scleral matrix, and displayed small club-like membrane protrusions. Differences in these arrangements in mature vs young chickens were not detected. The club-like membrane protrusions identified in chickens were rare in marmoset eyes, which instead exhibited two types of collagen fibrils discriminated by size, and were absent in the human eyes investigated. In marmoset and human eyes, elastic components were detected in the transition zone that were absent in chickens. In summary, cellular/membrane specializations indicating a mechanical interaction at the choroid-sclera transition zone were not detected in chicken, non-human primate or human eyes. If mechanotransduction is necessary for scleral growth, matrix integrity or development, alternative structural arrangements might be required.
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Affiliation(s)
- C. Platzl
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology -Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - A. Kaser-Eichberger
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology -Salzburg, Paracelsus Medical University, Salzburg, Austria
| | | | - F. Schroedl
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology -Salzburg, Paracelsus Medical University, Salzburg, Austria
- Corresponding author.
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She M, Li T, Shi W, Li B, Zhou X. AREG is involved in scleral remodeling in form‐deprivation myopia via the ERK1/2‐MMP‐2 pathway. FASEB J 2022; 36:e22289. [PMID: 35436023 DOI: 10.1096/fj.202200132r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/02/2022] [Accepted: 03/17/2022] [Indexed: 12/18/2022]
Affiliation(s)
- Man She
- Department of Ophthalmology Jinshan Hospital of Fudan University Shanghai China
| | - Tao Li
- Department of Ophthalmology Jinshan Hospital of Fudan University Shanghai China
| | - Wenqing Shi
- Department of Ophthalmology Jinshan Hospital of Fudan University Shanghai China
| | - Bing Li
- Central Laboratory Jinshan Hospital of Fudan University Shanghai China
| | - Xiaodong Zhou
- Department of Ophthalmology Jinshan Hospital of Fudan University Shanghai China
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Mehr JA, Hatami-Marbini H. Experimental and numerical analysis of electroactive characteristics of scleral tissue. Acta Biomater 2022; 143:127-137. [PMID: 35038585 DOI: 10.1016/j.actbio.2022.01.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/04/2022] [Accepted: 01/10/2022] [Indexed: 11/15/2022]
Abstract
The sclera provides mechanical support to retina and protects internal contents of the eye against external injuries. The scleral extracellular matrix is mainly composed of collagen fibers and proteoglycans (PGs). At physiological pH, collagen molecules are neutral but PGs contain negatively charged glycosaminoglycan chains. Thus, the sclera can be considered as a polyelectrolyte hydrogel and is expected to exhibit mechanical response when subjected to electrical stimulations. In this study, we mounted scleral strips, dissected from the posterior part of porcine eyes, at the center of a custom-designed container between two electrodes. The container was filled with NaCl solution and the bending deformation of scleral strips as a function of the applied electric voltage was measured experimentally. It was found that scleral strips reached to an average bending angle of 3°, 10° and 23° when subjected to 5V, 10V, and 15V, respectively. We also created a chemo-electro-mechanical finite element model for simulating the experimental measurements by solving coupled Poisson-Nernst-Plank and equilibrium mechanical field equations. The scleral fixed charge density and modulus of elasticity were found by fitting the experimental data. The ion concentration distribution inside the domain was found numerically and was used to explain the underlying mechanisms for the scleral electroactive response. The numerical simulations were also used to investigate the effects of various parameters such as the electric voltage and fixed charge density on the scleral deformation under an electric field. STATEMENT OF SIGNIFICANCE: This manuscript investigates the electroactive response of scleral tissue. It demonstrates that the sclera deforms mechanically when subjected to electrical stimulations. A chemo-electro-mechanical model is also presented in order to numerically capture the electromechanical response of the sclera. This numerical model is used to explain the experimental observations by finding the ion distribution inside the tissue under an electric field. This work is significant because it shows that the sclera is an electroactive polyanionic hydrogel and it provides new information about the underlying mechanisms governing its mechanical and electrical properties.
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Affiliation(s)
- Jafar Arash Mehr
- Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL USA
| | - Hamed Hatami-Marbini
- Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL USA.
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105
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Wang Y, Cao H. Corneal and Scleral Biomechanics in Ophthalmic Diseases: An Updated Review. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Bandzerewicz A, Gadomska-Gajadhur A. Into the Tissues: Extracellular Matrix and Its Artificial Substitutes: Cell Signalling Mechanisms. Cells 2022; 11:914. [PMID: 35269536 PMCID: PMC8909573 DOI: 10.3390/cells11050914] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 02/06/2023] Open
Abstract
The existence of orderly structures, such as tissues and organs is made possible by cell adhesion, i.e., the process by which cells attach to neighbouring cells and a supporting substance in the form of the extracellular matrix. The extracellular matrix is a three-dimensional structure composed of collagens, elastin, and various proteoglycans and glycoproteins. It is a storehouse for multiple signalling factors. Cells are informed of their correct connection to the matrix via receptors. Tissue disruption often prevents the natural reconstitution of the matrix. The use of appropriate implants is then required. This review is a compilation of crucial information on the structural and functional features of the extracellular matrix and the complex mechanisms of cell-cell connectivity. The possibilities of regenerating damaged tissues using an artificial matrix substitute are described, detailing the host response to the implant. An important issue is the surface properties of such an implant and the possibilities of their modification.
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Abstract
PURPOSE OF REVIEW Biomechanics is an important aspect of the complex family of diseases known as the glaucomas. Here, we review recent studies of biomechanics in glaucoma. RECENT FINDINGS Several tissues have direct and/or indirect biomechanical roles in various forms of glaucoma, including the trabecular meshwork, cornea, peripapillary sclera, optic nerve head/sheath, and iris. Multiple mechanosensory mechanisms and signaling pathways continue to be identified in both the trabecular meshwork and optic nerve head. Further, the recent literature describes a variety of approaches for investigating the role of tissue biomechanics as a risk factor for glaucoma, including pathological stiffening of the trabecular meshwork, peripapillary scleral structural changes, and remodeling of the optic nerve head. Finally, there have been advances in incorporating biomechanical information in glaucoma prognoses, including corneal biomechanical parameters and iridial mechanical properties in angle-closure glaucoma. SUMMARY Biomechanics remains an active aspect of glaucoma research, with activity in both basic science and clinical translation. However, the role of biomechanics in glaucoma remains incompletely understood. Therefore, further studies are indicated to identify novel therapeutic approaches that leverage biomechanics. Importantly, clinical translation of appropriate assays of tissue biomechanical properties in glaucoma is also needed.
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Affiliation(s)
- Babak N. Safa
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA
| | - Cydney A. Wong
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA
| | - Jungmin Ha
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA
| | - C. Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA
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Beach JM, Rizvi M, Lichtenfels CB, Vince R, More SS. Topical Review: Studies of Ocular Function and Disease Using Hyperspectral Imaging. Optom Vis Sci 2022; 99:101-113. [PMID: 34897230 DOI: 10.1097/opx.0000000000001853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Advances in imaging technology over the last two decades have produced significant innovations in medical imaging. Hyperspectral imaging (HSI) is one of these innovations, enabling powerful new imaging tools for clinical use and greater understanding of tissue optical properties and mechanisms underlying eye disease.Hyperspectral imaging is an important and rapidly growing area in medical imaging, making possible the concurrent collection of spectroscopic and spatial information that is usually obtained from separate optical recordings. In this review, we describe several mainstream techniques used in HSI, along with noteworthy advances in optical technology that enabled modern HSI techniques. Presented also are recent applications of HSI for basic and applied eye research, which include a novel method for assessing dry eye syndrome, clinical slit-lamp examination of corneal injury, measurement of blood oxygen saturation in retinal disease, molecular changes in macular degeneration, and detection of early stages of Alzheimer disease. The review also highlights work resulting from integration of HSI with other imaging tools such as optical coherence tomography and autofluorescence microscopy and discusses the adaptation of HSI for clinical work where eye motion is present. Here, we present the background and main findings from each of these reports along with specific references for additional details.
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Affiliation(s)
- James M Beach
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
| | - Madeeha Rizvi
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
| | - Caitlin B Lichtenfels
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
| | - Robert Vince
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
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Silva N, Bollemeijer JG, Ferreira A, Menéres MJ, Lemij H. Donor scleral graft vs pericardial graft vs scleral flap in tube drainage covering: advantages and disadvantages. EXPERT REVIEW OF OPHTHALMOLOGY 2022. [DOI: 10.1080/17469899.2022.2026217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Nisa Silva
- Ophthalmology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal
| | | | - André Ferreira
- Ophthalmology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Maria João Menéres
- Ophthalmology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade Do Porto, Porto, Portugal
| | - Hans Lemij
- Ophthalmology Department, Rotterdam Eye Hospital, Rotterdam Netherlands
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Silva N, Ferreira A, Baptista PM, Figueiredo A, Reis R, Sampaio I, Beirão J, Vinciguerra R, Menéres P, Menéres MJ. Corneal Biomechanics for Ocular Hypertension, Primary Open-Angle Glaucoma, and Amyloidotic Glaucoma: A Comparative Study by Corvis ST. Clin Ophthalmol 2022; 16:71-83. [PMID: 35035215 PMCID: PMC8754459 DOI: 10.2147/opth.s350029] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 12/21/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND To evaluate biomechanical parameters of the cornea provided by Corvis ST in patients with ocular hypertension, primary open-angle glaucoma, and amyloidotic glaucoma and to compare with healthy controls. METHODS This was a cross-sectional study of patients with ocular hypertension, primary open-angle glaucoma, and amyloidotic glaucoma that underwent Corvis ST imaging. Primary outcome was the comparison of corneal biomechanical parameters between study groups after adjusting for age, gender, Goldmann intraocular pressure (GAT-IOP), and prostaglandin analogues medication. Secondary outcome was the comparison of different IOP measurements in each group. RESULTS One hundred and eighty-three eyes from 115 patients were included: 61 with primary open-angle glaucoma, 32 with amyloidotic glaucoma, 37 with ocular hypertension and 53 were healthy controls. Amyloidotic glaucoma group had smaller radius (p=0.025), lower deflection amplitude at highest concavity (p=0.019), and higher integrated radius (p=0.014) than controls. Ocular hypertension group had higher stiffness parameter at first applanation (p=0.043) than those with primary open-angle glaucoma, and higher stress-strain index (p=0.049) than those with amyloidotic glaucoma. Biomechanically corrected intraocular pressure was significantly lower than Goldmann intraocular pressure in group with primary open-angle glaucoma (p=0.005) and control group (p=0.013), and Goldmann intraocular pressure adjusted for pachymetry in group with primary open-angle glaucoma (p=0.01). CONCLUSION Eyes with amyloidotic glaucoma have more deformable corneas, while eyes with ocular hypertension have less deformable corneas. These findings may be linked to the susceptibility to glaucomatous damage and progression. There were significant differences between Goldmann applanation tonometry and biomechanically corrected intraocular ocular pressure provided by Corvis ST.
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Affiliation(s)
- Nisa Silva
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
| | - André Ferreira
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
- Unit of Anatomy, Department of Biomedicine, Faculty of Medicine of University of Porto, Porto, 4200-319, Portugal
| | - Pedro Manuel Baptista
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
| | - Ana Figueiredo
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
| | - Rita Reis
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
| | - Isabel Sampaio
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
| | - João Beirão
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
- Department of Ophthalmology, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, 4050-313, Portugal
| | - Riccardo Vinciguerra
- Ophthalmology Department, Humanitas San Pio X Hospital, Milan, Italy
- The School of Engineering, University of Liverpool, Liverpool, UK
| | - Pedro Menéres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
- Department of Ophthalmology, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, 4050-313, Portugal
| | - Maria João Menéres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, 4099-001, Portugal
- Department of Ophthalmology, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, 4050-313, Portugal
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Yang J, Ouyang X, Fu H, Hou X, Liu Y, Xie Y, Yu H, Wang G. Advances in biomedical study of the myopia-related signaling pathways and mechanisms. Biomed Pharmacother 2021; 145:112472. [PMID: 34861634 DOI: 10.1016/j.biopha.2021.112472] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022] Open
Abstract
Myopia has become one of the most critical health problems in the world with the increasing time spent indoors and increasing close work. Pathological myopia may have multiple complications, such as myopic macular degeneration, retinal detachment, cataracts, open-angle glaucoma, and severe cases that can cause blindness. Mounting evidence suggests that the cause of myopia can be attributed to the complex interaction of environmental exposure and genetic susceptibility. An increasing number of researchers have focused on the genetic pathogenesis of myopia in recent years. Scleral remodeling and excessive axial elongating induced retina thinning and even retinal detachment are myopia's most important pathological manifestations. The related signaling pathways are indispensable in myopia occurrence and development, such as dopamine, nitric oxide, TGF-β, HIF-1α, etc. We review the current major and recent progress of biomedicine on myopia-related signaling pathways and mechanisms.
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Affiliation(s)
- Jing Yang
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Xinli Ouyang
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Hong Fu
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Xinyu Hou
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Yan Liu
- Department of Ophthalmology, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Yongfang Xie
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China.
| | - Haiqun Yu
- Department of Ophthalmology, Affiliated Hospital of Weifang Medical University, Weifang 261031, China.
| | - Guohui Wang
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China.
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112
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Liu S, Chen H, Ma W, Zhong Y, Liang Y, Gu L, Lu X, Li J. Non-coding RNAs and related molecules associated with form-deprivation myopia in mice. J Cell Mol Med 2021; 26:186-194. [PMID: 34841657 PMCID: PMC8742199 DOI: 10.1111/jcmm.17071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/01/2021] [Accepted: 11/15/2021] [Indexed: 01/18/2023] Open
Abstract
The role of miRNAs and its regulatory mechanism in myopia are indeterminate. Our study aimed to investigate potential myopia‐associated non‐coding RNAs and related molecules by performing a comprehensive bioinformatic analysis of miRNA expression profile of mice with form‐deprivation myopia (FDM). Differentially expressed miRNAs in two raw microarray data sets (GSE58124 and GSE84220) from Gene Expression Omnibus (GEO) database were comprehensively analysed using GEO2R. Target genes were predicted using miRDB and enriched with Metascape online tool. Protein‐protein interaction (PPI) networks were constructed utilizing STRING and Cytoscape. Significant differentially expressed miRNAs were validated by real‐time polymerase chain reaction (qRT‐PCR) using RNA extracted from monocular FDM ocular tissues. As result, we identified three upregulated miRNAs (mmu‐miR‐1936, mmu‐miR‐338‐5p, and mmu‐miR‐673‐3p) significantly associated with myopia in the two microarray data sets (p < 0.05 and |Log (Fold Change) |>1). GO functional analysis suggested these three miRNAs were targeted in genes mostly enriched in morphogenesis and developmental growth of retinal tissues. Enrichment analysis revealed top eight transcription factors, including PAX6 and Smad3, related to myopia. Ten hub genes, including Rbx1, Fbxl3, Fbxo27, Fbxl7, Fbxo4, Cul3, Cul2, Klhl5, Fbxl16 and Klhl42, associated with ubiquitin conjugation were identified. qRT‐PCR confirmed the increased expression of mmu‐miR‐1936 and mmu‐miR‐338‐5p (p < 0.05), but no statistical difference was observed in mmu‐miR‐673‐3p expression in myopic retinas. Our findings indicated mmu‐miR‐1936, mmu‐miR‐338‐5p and mmu‐miR‐673‐3p upregulation may be associated with myopia development via post‐transcriptional gene regulation, and identified potential molecules that could be further explored in future studies of the mechanism in myopia.
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Affiliation(s)
- Shanshan Liu
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Huijie Chen
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Wenbei Ma
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yanyan Zhong
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yingying Liang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Lishan Gu
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaohe Lu
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jiali Li
- Department of Ophthalmology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
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113
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Wang YH, Huang C, Tseng YL, Zhong J, Li XM. Refractive Error and Eye Health: An Umbrella Review of Meta-Analyses. Front Med (Lausanne) 2021; 8:759767. [PMID: 34805225 PMCID: PMC8599990 DOI: 10.3389/fmed.2021.759767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 10/04/2021] [Indexed: 12/28/2022] Open
Abstract
Purpose: To explore the associations between refractive errors and multiple eye health outcomes. Methods: This is an umbrella review based on systematic reviews with meta-analyses. In our study, refractive errors included myopia, hyperopia, astigmatism, and anisometropia. We reconducted the meta-analyses whose primary data were available in sufficient detail by random effect model. Heterogeneity was assessed by I 2. The main outcomes included myopic macular degeneration (MMD), retinal detachment (RD), cataract, open-angle glaucoma (OAG), strabismus, age-related macular degeneration (AMD), and diabetic retinopathy (DR). Results: Myopia was associated with increased risk of MMD (relative risk = 102.11, 95% CI 52.6-198.22), RD (3.45, 1.08-11.00), nuclear cataract (2.15, 1.53-3.03), posterior subcapsular (PSC) cataract (1.74, 1.41-2.15), OAG (1.95, 1.74-2.19), exotropia (5.23, 2.26-12.09), but decreased risk of DR (0.83, 0.66-1.04), and early AMD (0.80, 0.67-0.94). From mild-to-high myopia, the association strengthened for MMD, RD, nuclear cataract, PSC cataract, OAG, and DR. Hyperopia was associated with an increased risk of early AMD (1.09, 1.01-1.18) and esotropia (22.94, 10.20-51.62). Astigmatism and anisometropia were associated with increased risk of both exotropia and esotropia. Conclusions: Myopia, especially high myopia, demonstrated the highest risk for eye health outcomes, such as MMD, RD, OAG, nuclear and PSC cataracts, and exotropia. However, myopia was associated with a lower risk of early AMD and DR. Individuals with hyperopia are more likely to suffer early AMD and esotropia. Astigmatism and anisometropia predispose to strabismus. A lot of research studies on the mechanism of the associations are needed. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=239744; identifier: 239744.
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Affiliation(s)
- Yin-Hao Wang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Chen Huang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Center of Basic Medical Research, Peking University Third Hospital, Beijing, China
| | - Yu-Lin Tseng
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Jing Zhong
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Xue-Min Li
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
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114
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Atta G, Tempfer H, Kaser-Eichberger A, Traweger A, Heindl LM, Schroedl F. Is the human sclera a tendon-like tissue? A structural and functional comparison. Ann Anat 2021; 240:151858. [PMID: 34798297 DOI: 10.1016/j.aanat.2021.151858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 09/22/2021] [Accepted: 11/09/2021] [Indexed: 12/17/2022]
Abstract
Collagen rich connective tissues fulfill a variety of important functions throughout the human body, most of which having to resist mechanical challenges. This review aims to compare structural and functional aspects of tendons and sclera, two tissues with distinct location and function, but with striking similarities regarding their cellular content, their extracellular matrix and their low degree of vascularization. The description of these similarities meant to provide potential novel insight for both the fields of orthopedic research and ophthalmology.
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Affiliation(s)
- Ghada Atta
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Institute for Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Herbert Tempfer
- Institute for Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Alexandra Kaser-Eichberger
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology - Salzburg, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria
| | - Andreas Traweger
- Institute for Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Ludwig M Heindl
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Center for Integrated Oncology (CIO) Aachen - Bonn - Cologne - Düsseldorf, Cologne, Germany
| | - Falk Schroedl
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology - Salzburg, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria.
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115
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Osterried L, Gruber M, Böhringer D, Agostini H, Reinhard T. The Upper Paralimbal Zone is Especially Susceptible to Ruptures Due to Blunt Trauma. Klin Monbl Augenheilkd 2021; 239:1248-1258. [PMID: 34731899 DOI: 10.1055/a-1521-5124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Globe ruptures are ophthalmological emergencies where the primary diagnosis using a slit lamp is often a challenge. OBJECTIVES The retrospective case study aimed to characterise the predilection sites, the demographic profile and the causes of bursts due to blunt globe trauma. MATERIALS AND METHODS The surgical plan of the Eye Centre of the Medical Centre (University of Freiburg) was electronically searched using the keyword "globe rupture" over a period of 18 years (2000 - 2018). This led to 350 hits, which were scrutinised by hand. 134 globe ruptures due to blunt globe trauma were then identified. RESULTS The most common predilection sites were the upper nasal and the upper temporal paralimbal zones with 37 and 32% of the examined globe ruptures, respectively. The average age at the time of rupture was 60 (from 2 to 97) years. The median age was 62.5 years. 37% (49/134) of patients were female. The most frequent causes of accidents were falls (43%), "flying" wooden and metal objects (18%) and acts of violence (10%). CONCLUSIONS Special attention should be paid to the upper paralimbal zone in the exploratory primary care of globe ruptures. If the rupture occurred due to "flying" wooden and metal objects, the posterior sclera burst most frequently. The epidemiological data suggest that targeted prevention against falls for individuals over 60 years and consistent wearing of protective eyewear when working with wood or metal could reduce the incidence of bulbar bursting. It was also noticeable that acts of violence were the third most frequent cause of rupture, although woman did not report that they were affected by this. Given the high occurrence of violence against women, shame and stigma may lead to an incorrect inquiry about the cause of the accident. This could be mitigated by training employees specifically to take a sensitive history.
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Affiliation(s)
- Lea Osterried
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Deutschland
| | - Markus Gruber
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Deutschland
| | - Daniel Böhringer
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Deutschland
| | | | - Thomas Reinhard
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Deutschland
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116
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Modulation of the Physical Properties of 3D Spheroids Derived from Human Scleral Stroma Fibroblasts (HSSFs) with Different Axial Lengths Obtained from Surgical Patients. Curr Issues Mol Biol 2021; 43:1715-1725. [PMID: 34698138 PMCID: PMC8929070 DOI: 10.3390/cimb43030121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 12/23/2022] Open
Abstract
In the current study, to elucidate the pathological characteristics of myopic scleral stroma, three-dimensional (3D) cultures of human scleral stroma fibroblasts (HSSFs) with several axial lengths (AL, 22.80–30.63 mm) that were obtained from patients (n = 7) were examined. Among the three groups of ALs, <25 mm (n = 2), 25–30 mm (n = 2), and >30 mm (n = 3), the physical properties of the 3D HSSFs spheroids with respect to size and stiffness, the expressions of extracellular matrix (ECM) molecules, including collagen (COL) 1, 4, and 6 and fibronectin (FN) by qPCR and immunohistochemistry (IHC), and the mRNA expression of ECM metabolism modulators including hypoxia-inducible factor 1A (HIF 1A), HIF 2A, lysyl oxidase (LOX), tissue inhibitor of metalloproteinase (TIMP) 1–4, and matrix metalloproteinase (MMP) 2, 9, and 14 as well as several endoplasmic reticulum (ER) stress-related factors were compared. In the largest AL group (>30 mm), the 3D HSSFs spheroids were (1) significantly down-sized and less stiff compared to the other groups, and (2) significant changes were detected in the expression of some ECMs (qPCR; the up-regulation of COL1 and COL4, and the down-regulation of FN, IHC; the up-regulation of COL1 and FN, and down-regulation of COL4). The mRNA expressions of ECM modulators and ER stress-related genes were also altered with increasing AL length (up-regulation of HIF2A, MMP2, XBP1, and MMP14, down-regulation of LOX, TIMP 2 and 3, GRP78, GRP94, IRE1, and ATF6). In addition, a substantial down-regulation of some ER stress-related genes (ATF4, sXPB1 and CHOP) was observed in the 25–30 mm AL group. The findings presented herein suggest that small and stiffer 3D HSSFs spheroids in the largest AL group may accurately replicate the pathological significance of scleral thinning and weakening in myopic eyes. In addition, the modulation of several related factors among the different AL groups may also provide significant insights into our understanding of the molecular mechanisms responsible for causing myopic changes in the sclera.
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117
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Hu D, Jiang J, Ding B, Xue K, Sun X, Qian S. Mechanical Strain Regulates Myofibroblast Differentiation of Human Scleral Fibroblasts by YAP. Front Physiol 2021; 12:712509. [PMID: 34658907 PMCID: PMC8514697 DOI: 10.3389/fphys.2021.712509] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/30/2021] [Indexed: 12/14/2022] Open
Abstract
Scleral extracellular matrix (ECM) remodeling is thought to play a critical role in the pathogenesis of glaucoma. Mechanical strain induced by elevated intraocular pressure can promote myofibroblast differentiation of fibroblasts and result in scleral ECM remodeling; however, the underlying mechanism remains poorly understood. Yes-associated protein (YAP) is a mechanosensory protein and the key downstream transcriptional effector of the Hippo signaling pathway. Here, we investigated the role of YAP in mechanical strain-induced myofibroblast transformation during glaucoma scleral ECM remodeling. Integrative bioinformatics analyses were performed to identify the key pathways for the ECM remodeling of the sclera in glaucoma. Sprague–Dawley rats were used to establish a chronic ocular hypertension model, and the expression of collagen type I (COL1) and YAP in the sclera was analyzed by immunohistochemical analysis and Western blotting. Furthermore, human scleral fibroblasts (HSFs) were cultured and subjected to mechanical strain. In groups with or without the YAP siRNA or YAP inhibitor, cell proliferation, migration capacity, and the expression levels of YAP, COL1, and α-smooth muscle actin (α-SMA) were evaluated by Cell Counting Kit-8 assay, scratch assay, and Western blotting. The interactions between YAP and Smad3 were demonstrated by coimmunoprecipitation, and the expression levels of COL1 and α-SMA were evaluated in groups treated with or without the Smad3 inhibitor. We first revealed that the Hippo signaling pathway may be involved in mechanical strain-induced scleral ECM remodeling through bioinformatics analysis. Furthermore, the in vivo study showed upregulated YAP, COL1, and α-SMA expression in the hypertensive sclera of rats. In vitro, mechanical strain increased YAP and COL1 expression in HSFs and promoted myofibroblast differentiation. After YAP knockdown or inhibition with verteporfin, mechanical strain-induced fibrotic changes in HSFs were markedly suppressed. Additionally, YAP showed a protein interaction with Smad3, and the upregulation of a-SMA and COL1 in response to mechanical strain was also significantly downregulated following the inhibition of Smad3. In conclusion, mechanical strain activated scleral myofibroblast differentiation via YAP. The YAP pathway may play an important role in regulating scleral myofibroblast differentiation and ECM remodeling of the sclera in glaucoma.
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Affiliation(s)
- Di Hu
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China.,Department of Ophthalmology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Junhong Jiang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Baiyang Ding
- Spine Research Center of Wannan Medical College, Wuhu, China
| | - Kang Xue
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China.,State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Shaohong Qian
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China
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118
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Safa BN, Read AT, Ethier CR. Assessment of the viscoelastic mechanical properties of the porcine optic nerve head using micromechanical testing and finite element modeling. Acta Biomater 2021; 134:379-387. [PMID: 34274532 PMCID: PMC8542610 DOI: 10.1016/j.actbio.2021.07.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/11/2021] [Accepted: 07/08/2021] [Indexed: 11/26/2022]
Abstract
Optic nerve head (ONH) biomechanics is centrally involved in the pathogenesis of glaucoma, a blinding ocular condition often characterized by elevation and fluctuation of the intraocular pressure and resulting loads on the ONH. Further, tissue viscoelasticity is expected to strongly influence the mechanical response of the ONH to mechanical loading, yet the viscoelastic mechanical properties of the ONH remain unknown. To determine these properties, we conducted micromechanical testing on porcine ONH tissue samples, coupled with finite element modeling based on a mixture model consisting of a biphasic material with a viscoelastic solid matrix. Our results provide a detailed description of the viscoelastic properties of the porcine ONH at each of its four anatomical quadrants (i.e., nasal, superior, temporal, and inferior). We showed that the ONH's viscoelastic mechanical response can be explained by a dual mechanism of fluid flow and solid matrix viscoelasticity, as is common in other soft tissues. We obtained porcine ONH properties as follows: matrix Young's modulus E=1.895[1.056,2.391] kPa (median [min., max.]), Poisson's ratio ν=0.142[0.060,0.312], kinetic time-constant τ=214[89,921] sec, and hydraulic permeability k=3.854×10-1[3.457×10-2,9.994×10-1] mm4/(N.sec). These values can be used to design and fabricate physiologically appropriate ex vivo test environments (e.g., 3D cell culture) to further understand glaucoma pathophysiology. STATEMENT OF SIGNIFICANCE: Optic nerve head (ONH) biomechanics is an important aspect of the pathogenesis of glaucoma, the leading cause of irreversible blindness. The ONH experiences time-varying loads, yet the viscoelastic behavior of this tissue has not been characterized. Here, we measure the time-dependent response of the ONH in porcine eyes and use mechanical modeling to provide time-dependent mechanical properties of the ONH. This information allows us to identify time-varying stimuli in vivo which have timescales matching the characteristic response times of the ONH, and can also be used to design and fabricate ex vivo 3D cultures to study glaucoma pathophysiology in a physiologically relevant environment, enabling the discovery of new generations of glaucoma medications focusing on neuroprotection.
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Affiliation(s)
- Babak N Safa
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA
| | - A Thomas Read
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta GA, USA.
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119
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Hidalgo-Alvarez V, Dhowre HS, Kingston OA, Sheridan CM, Levis HJ. Biofabrication of Artificial Stem Cell Niches in the Anterior Ocular Segment. Bioengineering (Basel) 2021; 8:135. [PMID: 34677208 PMCID: PMC8533470 DOI: 10.3390/bioengineering8100135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
The anterior segment of the eye is a complex set of structures that collectively act to maintain the integrity of the globe and direct light towards the posteriorly located retina. The eye is exposed to numerous physical and environmental insults such as infection, UV radiation, physical or chemical injuries. Loss of transparency to the cornea or lens (cataract) and dysfunctional regulation of intra ocular pressure (glaucoma) are leading causes of worldwide blindness. Whilst traditional therapeutic approaches can improve vision, their effect often fails to control the multiple pathological events that lead to long-term vision loss. Regenerative medicine approaches in the eye have already had success with ocular stem cell therapy and ex vivo production of cornea and conjunctival tissue for transplant recovering patients' vision. However, advancements are required to increase the efficacy of these as well as develop other ocular cell therapies. One of the most important challenges that determines the success of regenerative approaches is the preservation of the stem cell properties during expansion culture in vitro. To achieve this, the environment must provide the physical, chemical and biological factors that ensure the maintenance of their undifferentiated state, as well as their proliferative capacity. This is likely to be accomplished by replicating the natural stem cell niche in vitro. Due to the complex nature of the cell microenvironment, the creation of such artificial niches requires the use of bioengineering techniques which can replicate the physico-chemical properties and the dynamic cell-extracellular matrix interactions that maintain the stem cell phenotype. This review discusses the progress made in the replication of stem cell niches from the anterior ocular segment by using bioengineering approaches and their therapeutic implications.
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Affiliation(s)
- Veronica Hidalgo-Alvarez
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Hala S. Dhowre
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Olivia A. Kingston
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Carl M. Sheridan
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Hannah J. Levis
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
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120
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Kabaalioğlu Güner M, Mehra A, Smith WM. Novel strategies for the diagnosis and treatment of scleritis. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1984881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Ankur Mehra
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
| | - Wendy M. Smith
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
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121
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Zhao F, Zhou H, Chen W, Zhao C, Zheng Y, Tao Y, Pan M, Reinach PS, Zhu J, An J, Lu R, Chen JF, Tang H, Zeng C, Qu J, Zhou X. Declines in PDE4B activity promote myopia progression through downregulation of scleral collagen expression. Exp Eye Res 2021; 212:108758. [PMID: 34506801 DOI: 10.1016/j.exer.2021.108758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 08/19/2021] [Accepted: 09/02/2021] [Indexed: 10/20/2022]
Abstract
Myopia is the most common cause of a visual refractive error worldwide. Cyclic adenosine monophosphate (cAMP)-linked signaling pathways contribute to the regulation of myopia development, and increases in cAMP accumulation promote myopia progression. To pinpoint the underlying mechanisms by which cAMP modulates myopia progression, we performed scleral transcriptome sequencing analysis in form-deprived mice, a well-established model of myopia development. Form deprivation significantly inhibited the expression levels of genes in the cAMP catabolic pathway. Quantitative real-time polymerase chain reaction analysis validated that the gene expression level of phosphodiesterase 4B (PDE4B), a cAMP hydrolase, was downregulated in form-deprived mouse eyes. Under visually unobstructed conditions, loss of PDE4B function in Pde4b-knockout mice increased the myopic shift in refraction, -3.661 ± 1.071 diopters, more than that in the Pde4b-wildtype littermates (P < 0.05). This suggests that downregulation and inhibition of PDE4B gives rise to myopia. In guinea pigs, subconjunctival injection of rolipram, a selective inhibitor of PDE4, led to myopia in normal eyes, and it also enhanced form-deprivation myopia (FDM). Subconjunctival injection of dibutyryl-cyclic adenosine monophosphate, a cAMP analog, induced only a myopic shift in the normal visually unobstructed eyes, but it did not enhance FDM. As myopia developed, axial elongation occurred during scleral remodeling that was correlated with changes in collagen fibril thickness and distribution. The median collagen fibril diameter in the FDM + rolipram group, 55.09 ± 1.83 nm, was thinner than in the FDM + vehicle group, 59.33 ± 2.06 nm (P = 0.011). Thus, inhibition of PDE4 activity with rolipram thinned the collagen fibril diameter relative to the vehicle treatment in form-deprived eyes. Rolipram also inhibited increases in collagen synthesis induced by TGF-β2 in cultured human scleral fibroblasts. The current results further support a role for PDE enzymes such as PDE4B in the regulation of normal refractive development and myopia because either loss or inhibition of PDE4B function increased myopia and FDM development through declines in the scleral collagen fibril diameter.
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Affiliation(s)
- Fuxin Zhao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China.
| | - Hui Zhou
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Wei Chen
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China; Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, The Chinese Academy of Sciences, Beijing, China
| | - Chenchen Zhao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Yangyang Zheng
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Yijin Tao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Miaozhen Pan
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Peter S Reinach
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Jiadi Zhu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Jianhong An
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Runxia Lu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Jiang-Fan Chen
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Huifang Tang
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Changqing Zeng
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, The Chinese Academy of Sciences, Beijing, China
| | - Jia Qu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China; Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences (2019RU025), Wenzhou, Zhejiang, China
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China; Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences (2019RU025), Wenzhou, Zhejiang, China.
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122
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Li Y, Mitchell W, Elze T, Zebardast N. Association Between Diabetes, Diabetic Retinopathy, and Glaucoma. Curr Diab Rep 2021; 21:38. [PMID: 34495413 DOI: 10.1007/s11892-021-01404-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/19/2021] [Indexed: 12/28/2022]
Abstract
PURPOSE OF REVIEW The strength of the relationship between diabetes, diabetic retinopathy (DR), and glaucoma remains controversial. We review evidence supporting and refuting this association and explore mechanistic pathological and treatment relationships linking these diseases. RECENT FINDINGS While studies have shown diabetes/DR may increase the risk for glaucoma, this remains inconsistently demonstrated. Diabetes/DR may contribute toward glaucomatous optic neuropathy indirectly (either by increasing intraocular pressure or vasculopathy) or through direct damage to the optic nerve. However, certain elements of diabetes may slow glaucoma progression, and diabetic treatment may concurrently be beneficial in glaucoma management. Diabetes plays a significant role in poor outcomes after glaucoma surgery. While the relationship between diabetes/DR and glaucoma remains controversial, multiple mechanistic links connecting pathophysiology and management of diabetes, DR, and glaucoma have been made. However, a deeper understanding of the causes of disease association is needed.
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Affiliation(s)
- Yangjiani Li
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, 02114, USA
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, 510060, China
| | - William Mitchell
- Department of Ophthalmology, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA, 02114, USA
- Department of Ophthalmology, Royal Victorian Eye and Ear, Melbourne, VIC, 3002, Australia
| | - Tobias Elze
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, 02114, USA
| | - Nazlee Zebardast
- Department of Ophthalmology, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA, 02114, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, 02115, USA.
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Siesky B, Harris A, Vercellin ACV, Guidoboni G, Tsai JC. Ocular blood flow as it relates to race and disease on glaucoma. ADVANCES IN OPHTHALMOLOGY AND OPTOMETRY 2021; 6:245-262. [PMID: 35252630 PMCID: PMC8896810 DOI: 10.1016/j.yaoo.2021.04.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Glaucoma is a multifactorial progressive and degenerative optic neuropathy representing one of the world's leading cause of irreversible blindness. Currently, reduction of intraocular pressure remains the only universally approved therapy, yet a wealth of studies has identified significant vascular contributions to the disease process in certain individuals. Population-based studies have identified important racial disparities and differential risk factors in glaucoma prevalence, incidence, and progression. A more significant vascular component has been identified in persons of African descent. Elucidating risk modifiers, including genetic and racial influence, is important when considering individually tailored clinical management of glaucoma. The application of artificial intelligence and mathematical modeling inclusive of demographic considerations, vascular health, and clinical biomarkers may help reduce disease disparities, advance personalized medicine, and provide a comprehensive model of glaucoma.
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Affiliation(s)
- Brent Siesky
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Alon Harris
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Alice C. Verticchio Vercellin
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Ophthalmology, University of Pavia, Pavia, Italy
- IRCCS - Fondazione Bietti, Rome, Italy
| | - Giovanna Guidoboni
- Department of Electrical Engineering and Computer Science, Department of Mathematics, University of Missouri, Columbia, MO, United States
| | - James C. Tsai
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
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Hatami-Marbini H, Pachenari M. Tensile Viscoelastic Properties of the Sclera after Glycosaminoglycan Depletion. Curr Eye Res 2021; 46:1299-1308. [PMID: 34325593 DOI: 10.1080/02713683.2021.1874026] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Fibrillar collagen network and glycosaminoglycans (GAGs) are the primary components of extracellular matrix (ECM) of the sclera. The main goal of this study was to investigate the possible structural roles of GAGs in the scleral tensile properties as a function of preconditioning and displacement rate. METHODS Four-step uniaxial stress-relaxation tests were used for characterizing the viscoelastic tensile response of the posterior porcine sclera with and without enzymatic GAG removal. The scleral strips were divided into different groups based on the displacement rate and the presence or absence of a preconditioning step in the loading protocol. The groups were (1) displacement rate of 0.2 mm/min without preconditioning, (2) displacement rate of 1 mm/min without preconditioning, (3) displacement rate of 0.2 mm/min with preconditioning, and (4) displacement rate of 1 mm/min with preconditioning. The peak stress, equilibrium stress, and the equilibrium elastic modulus were calculated for all specimens and compared against each other. RESULTS Increasing the displacement rate from 0.2 mm/min to 1.0 mm/min was found to cause an insignificant change in the equilibrium stress and equilibrium elastic modulus of porcine scleral strips. Removal of GAGs resulted in an overall stiffer tensile behavior independent of the displacement rate in samples that were not preconditioned (P < .05). The behavior of preconditioned samples with and without GAG removal was not significantly different from each other. CONCLUSIONS The experimental measurements of the present study showed that GAGs play an important role in the mechanical properties of the posterior porcine sclera. Furthermore, using a preconditioning step in the uniaxial testing protocol resulted in not being able to identify any significant difference in the tensile behavior of GAG depleted and normal scleral strips.
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Affiliation(s)
- Hamed Hatami-Marbini
- Computational Biomechanics Research Laboratory, Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL, USA
| | - Mohammad Pachenari
- Computational Biomechanics Research Laboratory, Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL, USA
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125
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Kong W, Zhang J, Lu C, Ding Y, Meng Y. Glaucoma in mucopolysaccharidoses. Orphanet J Rare Dis 2021; 16:312. [PMID: 34266471 PMCID: PMC8281695 DOI: 10.1186/s13023-021-01935-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 06/27/2021] [Indexed: 11/30/2022] Open
Abstract
Mucopolysaccharidoses are a group of lysosomal storage disorders that are caused by deficiency of enzymes involved in glycosaminoglycans degradation. Due to low prevalence and high childhood mortality, researches on mucopolysaccharidoses were mainly focused on the fatal manifestations. With the development of treatments, more and more mucopolysaccharidoses patients were treated by approved therapies, thereby getting prolonged life span and improved quality of life. Abnormal accumulation of glycosaminoglycans in the eye may block trabecular meshwork, thicken sclera and change mechanical behavior of lamina cribrosa, which, by increasing intraocular pressure and damaging optic nerve, could cause glaucoma. Glaucoma was the leading cause of irreversible blindness worldwide, but it was rarely reported in mucopolysaccharidoses patients. Although non-fatal, it seriously affected quality of life. Prevalence of glaucoma in mucopolysaccharidoses patients (ranged from 2.1 to 12.5%) indicated that glaucoma in patients with mucopolysaccharidoses was worthy of attention and further study, thereby improving the quality of life for MPSs patients.
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Affiliation(s)
- Weijing Kong
- Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Jing Zhang
- Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Cheng Lu
- Beijing Hong Jian Medical Device Company, Beijing, 100176, China
| | - Yingxue Ding
- Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China.
| | - Yan Meng
- Department of Pediatrics, Chinese PLA General Hospital, Beijing, 100853, China.
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Ma Y, Moroi SE, Roberts CJ. Non-invasive Clinical Measurement of Ocular Rigidity and Comparison to Biomechanical and Morphological Parameters in Glaucomatous and Healthy Subjects. Front Med (Lausanne) 2021; 8:701997. [PMID: 34291068 PMCID: PMC8287026 DOI: 10.3389/fmed.2021.701997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: To assess ocular rigidity using dynamic optical coherence tomography (OCT) videos in glaucomatous and healthy subjects, and to evaluate how ocular rigidity correlates with biomechanical and morphological characteristics of the human eye. Methods: Ocular rigidity was calculated using Friedenwald's empirical equation which estimates the change in intraocular pressure (IOP) produced by volumetric changes of the eye due to choroidal pulsations with each heartbeat. High-speed OCT video was utilized to non-invasively measure changes in choroidal volume through time-series analysis. A control-case study design was based on 23 healthy controls and 6 glaucoma cases. Multiple diagnostic modalities were performed during the same visit including Spectralis OCT for nerve head video, Pascal Dynamic Contour Tonometry for IOP and ocular pulse amplitude (OPA) measurement, Corvis ST for measuring dynamic biomechanical response, and Pentacam for morphological characterization. Results: Combining glaucoma and healthy cohorts (n = 29), there were negative correlations between ocular rigidity and axial length (Pearson R = −0.53, p = 0.003), and between ocular rigidity and anterior chamber volume (R = −0.64, p = 0.0002). There was a stronger positive correlation of ocular rigidity and scleral stiffness (i.e., stiffness parameter at the highest concavity [SP-HC]) (R = 0.62, p = 0.0005) compared to ocular rigidity and corneal stiffness (i.e., stiffness parameter at the first applanation [SP-A1]) (R = 0.41, p = 0.033). In addition, there was a positive correlation between ocular rigidity and the static pressure-volume ratio (P/V ratio) (R = 0.72, p < 0.0001). Conclusions: Ocular rigidity was non-invasively assessed using OCT video and OPA in a clinic setting. The significant correlation of ocular rigidity with biomechanical parameters, SP-HC and P/V ratio, demonstrated the validity of the ocular rigidity measurement. Ocular rigidity is driven to a greater extent by scleral stiffness than corneal stiffness. These in vivo methods offer an important approach to investigate the role of ocular biomechanics in glaucoma.
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Affiliation(s)
- Yanhui Ma
- Department of Ophthalmology and Visual Sciences, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Sayoko E Moroi
- Department of Ophthalmology and Visual Sciences, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Cynthia J Roberts
- Department of Ophthalmology and Visual Sciences, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
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Juliano J, Burkemper B, Lee J, Nelson A, LeTran V, Chu Z, Zhou G, Jiang X, Wang RK, Varma R, Richter GM. Longer Axial Length Potentiates Relationship of Intraocular Pressure and Peripapillary Vessel Density in Glaucoma Patients. Invest Ophthalmol Vis Sci 2021; 62:37. [PMID: 34311470 PMCID: PMC8322720 DOI: 10.1167/iovs.62.9.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to investigate how axial length (AL) changes the relationship of intraocular pressure (IOP) with peripapillary vessel density (pVD) in glaucoma versus non-glaucomatous eyes. Methods A population-based, cross-sectional study of 2127 African Americans aged 40 years and older in Inglewood, California, were imaged with 6 × 6-mm optic disc optical coherence tomography angiography scans. There were 1028 healthy subjects (1539 eyes) and 65 subjects with glaucoma (86 eyes) who met inclusion criteria. A multivariable linear mixed effects regression model investigated the relationship of IOP on pVD after controlling for signal strength, retinal nerve fiber layer thickness, and age. These results were stratified by AL groups. Results Higher IOP was a significant predictor of lower pVD among subjects with glaucoma (P = 0.009), but not among healthy subjects (P = 0.26). After stratifying by the sample median AL (23.46 mm), higher IOP was associated with lower pVD among subjects with glaucoma with longer AL (≥ 23.46 mm, P = 0.005), but not among those in the shorter AL (< 23.46 mm, P = 0.45). IOP was not significantly associated with pVD among healthy subjects in either AL stratum. Conclusions Among subjects with glaucoma with longer AL, IOP was significantly associated with pVD. This relationship was not seen among subjects with glaucoma with shorter AL or non-glaucomatous subjects in either AL group. These findings support the hypothesis that disturbed retinal autoregulation may be present in subjects with glaucoma with longer AL. Longitudinal studies are needed to further investigate whether axial elongation increases glaucoma risk by compromising retinal autoregulation.
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Affiliation(s)
- Joseph Juliano
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
| | - Bruce Burkemper
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
| | - Jae Lee
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
| | - Andrew Nelson
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
| | - Vivian LeTran
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
| | - Zhongdi Chu
- Department of Bioengineering, University of Washington, Seattle, Washington, United States
| | - Gabriella Zhou
- Department of Bioengineering, University of Washington, Seattle, Washington, United States
| | - Xuejuan Jiang
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, United States
| | - Rohit Varma
- Southern California Eye Institute, CHA Hollywood Presbyterian Medical Center, Los Angeles, California, United States
| | - Grace M Richter
- USC Roski Eye Institute, Keck School of Medicine of University of Southern California, Los Angeles, California, United States
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Bianco G, Levy AM, Grytz R, Fazio MA. Effect of different preconditioning protocols on the viscoelastic inflation response of the posterior sclera. Acta Biomater 2021; 128:332-345. [PMID: 33932581 DOI: 10.1016/j.actbio.2021.04.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 04/18/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022]
Abstract
Preconditioning by repeated cyclic loads is routinely used in ex vivo mechanical testing of soft biological tissues. The goal of preconditioning is to achieve a steady and repeatable mechanical response and to measure material properties that are representative of the in vivo condition. Preconditioning protocols vary across studies, and their effect on the viscoelastic response of tested soft tissue is typically not reported or analyzed. We propose a methodology to systematically analyze the preconditioning process with application to inflation testing. We investigated the effect of preconditioning on the viscoelastic inflation response of tree shrew posterior sclera using two preconditioning protocols: (i) continuous cyclic loading-unloading without rest and (ii) cyclic loading-unloading with 15-min rest between cycles. Posterior scleral surface strain was measured using three-dimensional Digital Image Correlation (3D-DIC). We used five variables of characterizing features of the stress-strain loop curve to compare the two preconditioning protocols. Our results showed protocol-dependent differences in the tissue response during preconditioning and at the preconditioned state. Incorporating a resting time between preconditioning cycles significantly decreased the number of cycles (10.5 ± 2.9 cycles vs. 3.1 ± 0.5 cycles, p < 0.001) but increased the total time (15.8 ± 4.4 min vs. 51.2 ± 8.3 min, p < 0.001) needed to reach preconditioned state. At the preconditioned state, 2 of 5 characteristic variables differed significantly between protocols: hysteresis loop area (difference=0.023 kJ/m3, p = 0.0020) and elastic modulus at high IOPs (difference=24.0 MPa, p = 0.0238). Our results suggest that the analysis of the preconditioning process is an essential part of inflation experiments and a prerequisite to properly characterize the tissue viscoelastic response. Furthermore, material properties obtained at the preconditioned state can be impacted by the resting time used during preconditioning and may not be directly compared across studies if the resting time varies by 15 min between studies. STATEMENT OF SIGNIFICANCE: Although applying a preconditioning protocol by repeated cyclic loads is common practice in ex vivo mechanical characterization of soft tissues, the tissue response is typically not reported or analyzed, and the protocol's potential effect on the response remains unclear. This is partially caused by lack of a standardized methodology to precondition soft tissues. We present the first systematic analysis of two representative preconditioning protocols used during inflation testing in ocular biomechanics. Our results show protocol-dependent differences in the viscoelastic response during the preconditioning process and at the preconditioned state. Consequently, the analysis of the preconditioning response represents an essential part of mechanical testing and a prerequisite to properly characterize the tissue viscoelastic response. The effect of preconditioning on the preconditioned state response must be considered when comparing results across studies with different preconditioning protocols.
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129
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Atta G, Schroedl F, Kaser-Eichberger A, Spitzer G, Traweger A, Heindl LM, Tempfer H. Scleraxis expressing scleral cells respond to inflammatory stimulation. Histochem Cell Biol 2021; 156:123-132. [PMID: 33966129 PMCID: PMC8397666 DOI: 10.1007/s00418-021-01985-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2021] [Indexed: 11/15/2022]
Abstract
The sclera is an ocular tissue rich of collagenous extracellular matrix, which is built up and maintained by relatively few, still poorly characterized fibroblast-like cells. The aims of this study are to add to the characterization of scleral fibroblasts and to examine the reaction of these fibroblasts to inflammatory stimulation in an ex vivo organotypic model. Scleras of scleraxis-GFP (SCX-GFP) mice were analyzed using immunohistochemistry and qRT-PCR for the expression of the tendon cell associated marker genes scleraxis (SCX), mohawk and tenomodulin. In organotypic tissue culture, explanted scleras of adult scleraxis GFP reporter mice were exposed to 10 ng/ml recombinant interleukin 1-ß (IL1-ß) and IL1-ß in combination with dexamethasone. The tissue was then analyzed by immunofluorescence staining of the inflammation- and fibrosis-associated proteins IL6, COX-2, iNOS, connective tissue growth factor, MMP2, MMP3, and MMP13 as well as for collagen fibre degradation using a Collagen Hybridizing Peptide (CHP) binding assay. The mouse sclera displayed a strong expression of scleraxis promoter-driven GFP, indicating a tendon cell-like phenotype, as well as expression of scleraxis, tenomodulin and mohawk mRNA. Upon IL1-ß stimulation, SCX-GFP+ cells significantly upregulated the expression of all proteins analysed. Moreover, IL1-ß stimulation resulted in significant collagen degradation. Adding the corticosteroid dexamethasone significantly reduced the response to IL1-ß stimulation. Collagen degradation was significantly enhanced in the IL1-ß group. Dexamethasone demonstrated a significant rescue effect. This work provides insights into the characteristics of scleral cells and establishes an ex vivo model of scleral inflammation.
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Affiliation(s)
- Ghada Atta
- Department of Ophthalmology, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany.,Institute of Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Falk Schroedl
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology - Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Alexandra Kaser-Eichberger
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology - Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Gabriel Spitzer
- Institute of Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Andreas Traweger
- Institute of Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Ludwig M Heindl
- Department of Ophthalmology, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany.,Center for Integrated Oncology (CIO) Aachen-Bonn-Cologne-Düsseldorf, Cologne, Germany
| | - Herbert Tempfer
- Institute of Tendon and Bone Regeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria. .,Austrian Cluster for Tissue Regeneration, Vienna, Austria.
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130
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Han D, He MN, Zhu Y, Zhang Y, Wei RH. Protective effects of riboflavin-UVA-mediated posterior sclera collagen cross-linking in a guinea pig model of form-deprived myopia. Int J Ophthalmol 2021; 14:333-340. [PMID: 33747806 DOI: 10.18240/ijo.2021.03.01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/21/2020] [Indexed: 01/17/2023] Open
Abstract
AIM To evaluate the effect of posterior sclera collagen cross-linking induced by riboflavin-ultraviolet A (UVA) on form-deprived myopia in guinea pigs. METHODES Twenty-five pigmented guinea pigs of 3-week-old were randomly assigned into 4 groups that included normal control (NOR, n=7), form-deprived (FDM, n=7), normal with riboflavin-UVA cross-linking (NOR+CL, n=5) and form-deprived with cross-linking (FDM+CL, n=6). The NOR+CL group and the FDM+CL group received the riboflavin-UVA induced cross-linking at day 0. FDM was induced by monocularly deprived with facemask in the right eyes. The refraction, axial length and corneal curvature were measured by retinoscopy, A-scan and keratometer respectively in scheduled time points (day 0 and 1, 2, 3, 4wk after form-deprivation). At the end of 4 weeks' experiment, stress-strain tests of sclera were measured and morphological changes of sclera and retina were examined. RESULTS After 4wk, the interocular difference of refractive error were -0.11±0.67, -2.93±0.56, 1.10±0.58, and -1.63±0.41 D in the NOR, FDM, NOR+CL, and FDM+CL groups respectively. Mixed-effect linear model revealed significant effect of FDM (P<0.01) and CL (P<0.001). Also, after 4wk, the interocular difference of axial length were 0.01±0.04, 0.29±0.07, -0.13±0.06, and 0.11±0.05 mm in the NOR, FDM, NOR+CL, and FDM+CL group. Mixed-effect linear model revealed significant effect of FDM (P<0.001) and CL (P<0.01). As for corneal curvature, significant interocular difference have not found between any of the two groups. At the end of this experiment, the ultimate stress and elastic modulus were found significantly increased in both CL groups. But no difference was found in the groups without cross-linked. There was no abnormality observed in the retina and RPE cells of the treated eyes. CONCLUSION The posterior sclera collagen cross-linking induced by riboflavin-UVA can slow down the progress of myopia and increase the sclera biomechanical strength in the guinea pig model of form-deprived myopia.
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Affiliation(s)
- Ding Han
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Mei-Nan He
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Ying Zhu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Yan Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Rui-Hua Wei
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
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131
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van Dijk EHC, Boon CJF. Serous business: Delineating the broad spectrum of diseases with subretinal fluid in the macula. Prog Retin Eye Res 2021; 84:100955. [PMID: 33716160 DOI: 10.1016/j.preteyeres.2021.100955] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/14/2021] [Accepted: 02/19/2021] [Indexed: 02/08/2023]
Abstract
A wide range of ocular diseases can present with serous subretinal fluid in the macula and therefore clinically mimic central serous chorioretinopathy (CSC). In this manuscript, we categorise the diseases and conditions that are part of the differential diagnosis into 12 main pathogenic subgroups: neovascular diseases, vitelliform lesions, inflammatory diseases, ocular tumours, haematological malignancies, paraneoplastic syndromes, genetic diseases, ocular developmental anomalies, medication-related conditions and toxicity-related diseases, rhegmatogenous retinal detachment and tractional retinal detachment, retinal vascular diseases, and miscellaneous diseases. In addition, we describe 2 new clinical pictures associated with macular subretinal fluid accumulation, namely serous maculopathy with absence of retinal pigment epithelium (SMARPE) and serous maculopathy due to aspecific choroidopathy (SMACH). Differentiating between these various diseases and CSC can be challenging, and obtaining the correct diagnosis can have immediate therapeutic and prognostic consequences. Here, we describe the key differential diagnostic features of each disease within this clinical spectrum, including representative case examples. Moreover, we discuss the pathogenesis of each disease in order to facilitate the differentiation from typical CSC.
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Affiliation(s)
- Elon H C van Dijk
- Department of Ophthalmology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, the Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
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132
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Ferrara M, Lugano G, Sandinha MT, Kearns VR, Geraghty B, Steel DHW. Biomechanical properties of retina and choroid: a comprehensive review of techniques and translational relevance. Eye (Lond) 2021; 35:1818-1832. [PMID: 33649576 PMCID: PMC8225810 DOI: 10.1038/s41433-021-01437-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/06/2020] [Accepted: 01/26/2021] [Indexed: 02/06/2023] Open
Abstract
Studying the biomechanical properties of biological tissue is crucial to improve our understanding of disease pathogenesis. The biomechanical characteristics of the cornea, sclera and the optic nerve head have been well addressed with an extensive literature and an in-depth understanding of their significance whilst, in comparison, knowledge of the retina and choroid is relatively limited. Knowledge of these tissues is important not only to clarify the underlying pathogenesis of a wide variety of retinal and vitreoretinal diseases, including age-related macular degeneration, hereditary retinal dystrophies and vitreoretinal interface diseases but also to optimise the surgical handling of retinal tissues and, potentially, the design and properties of implantable retinal prostheses and subretinal therapies. Our aim with this article is to comprehensively review existing knowledge of the biomechanical properties of retina, internal limiting membrane (ILM) and the Bruch’s membrane–choroidal complex (BMCC), highlighting the potential implications for clinical and surgical practice. Prior to this we review the testing methodologies that have been used both in vitro, and those starting to be used in vivo to aid understanding of their results and significance.
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Affiliation(s)
| | - Gaia Lugano
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | | | - Victoria R Kearns
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Brendan Geraghty
- Musculoskeletal and Ageing Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK.
| | - David H W Steel
- Sunderland Eye Infirmary, Sunderland, UK. .,Bioscience Institute, Newcastle University, Newcastle Upon Tyne, UK.
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133
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Pachenari M, Hatami-Marbini H. Regional Differences in the Glycosaminoglycan Role in Porcine Scleral Hydration and Mechanical Behavior. Invest Ophthalmol Vis Sci 2021; 62:28. [PMID: 33749719 PMCID: PMC7991977 DOI: 10.1167/iovs.62.3.28] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This study characterized the role of glycosaminoglycans (GAGs) in the hydration, thickness, and biomechanical properties of posterior and anterior porcine sclera. Methods The scleral discs and strips were obtained from the anterior and posterior parts of porcine eyes, and their initial hydration and thickness were measured. The anterior and posterior scleral discs were used to show the efficacy of the GAG removal protocol by quantifying their GAG content. The strips were divided into three groups of PBS treatment, buffer treatment, and enzyme treatment in order to assess the effects of different treatment procedures on the thickness, hydration, and viscoelastic properties of the samples. The mechanical properties of the strips were determined by performing uniaxial tensile stress relaxation experiments. Results It was found that the control and buffer groups had insignificant differences in all measured quantities. The samples from the posterior region had a significantly larger GAG content and thickness in comparison with those from anterior region; however, there was an insignificant difference in their hydration. The GAG depletion process decreased the hydration of both anterior and posterior samples significantly (P < 0.05). Furthermore, the mechanical tests showed that the removal of GAGs resulted in stiffer mechanical behavior in both anterior and posterior samples (P < 0.05). In particular, the peak stress and equilibrium stress were significantly larger for the strips in the enzyme treatment group. Conclusions GAGs and their interaction with the collagen network are important in defining the hydration and mechanical properties of both posterior and anterior sclera.
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Affiliation(s)
- Mohammad Pachenari
- Computational Biomechanics Research Laboratory, Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Hamed Hatami-Marbini
- Computational Biomechanics Research Laboratory, Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, Illinois, United States
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Nahar N, Mohamed S, Mustapha NM, Lau S, Ishak NIM, Umran NS. Metformin attenuated histopathological ocular deteriorations in a streptozotocin-induced hyperglycemic rat model. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2021; 394:457-467. [PMID: 33047165 DOI: 10.1007/s00210-020-01989-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/06/2020] [Indexed: 12/14/2022]
Abstract
Diabetes mellitus (DM) often causes ocular disorders leading to vision loss. Metformin is commonly prescribed for type 2 diabetes. This study assessed the effect of metformin on hyperglycemic histopathological eye abnormalities and some possible pathways involved. Male rats were divided into 3 groups (N = 6), namely, healthy control, hyperglycemic non-treated control, and hyperglycemic rats treated with 200 mg/kg metformin. Two weeks after diabetes induction by an intraperitoneal streptozotocin (60 mg streptozotocin (STZ)/kg) injection, the rats develop ocular abnormalities, and metformin (200 mg/kg) treatment was administered daily. Rats underwent dilated retinal digital ophthalmoscope examination and graded for diabetic retinopathy. Rats were sacrificed at 12 weeks, and the cornea, lens, sclera, ciliary body, iris, conjunctiva, retinal, and optic nerve were examined histologically. Rats' fasting blood glucose and body weight were monitored. Serum tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), claudin-1, and glutathione/malondialdehyde ratios were analyzed. Metformin significantly attenuated diabetes-related histopathological ocular deteriorations in the cornea, lens, sclera, ciliary body, iris, conjunctiva, retina, and optic nerve partly by restoring serum TNF-α, VEGF, claudin-1, and glutathione/malondialdehyde ratios without significantly affecting the fasting blood glucose levels or body weight in these hyperglycemic rats. Metformin attenuated hyperglycemia-associated histopathological eye deteriorations, possibly partly by ameliorating vascular leakage, oxidative stress, inflammation, and neovascularization, without affecting the fasting blood glucose levels or body weights in these STZ-induced diabetic rats.
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Affiliation(s)
- Nazmun Nahar
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Suhaila Mohamed
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
| | | | - SengFong Lau
- Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia
| | - Nur Iliyani Mohd Ishak
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Norshahira Solehah Umran
- UPM-MAKNA Laboratory of Cancer Research, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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135
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Yang B, Lee PY, Hua Y, Brazile B, Waxman S, Ji F, Zhu Z, Sigal IA. Instant polarized light microscopy for imaging collagen microarchitecture and dynamics. JOURNAL OF BIOPHOTONICS 2021; 14:e202000326. [PMID: 33103363 PMCID: PMC7887070 DOI: 10.1002/jbio.202000326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/17/2020] [Accepted: 10/23/2020] [Indexed: 05/29/2023]
Abstract
Collagen fibers are a primary load-bearing component of connective tissues and are therefore central to tissue biomechanics and pathophysiology. Understanding collagen architecture and behavior under dynamic loading requires a quantitative imaging technique with simultaneously high spatial and temporal resolutions. Suitable techniques are thus rare and often inaccessible. In this study, we present instant polarized light microscopy (IPOL), in which a single snapshot image encodes information on fiber orientation and retardance, thus fulfilling the requirement. We utilized both simulation and experimental data from collagenous tissues of chicken tendon, sheep eye, and porcine heart to evaluate the effectiveness of IPOL as a quantitative imaging technique. We demonstrate that IPOL allows quantitative characterization of micron-scale collagen fiber architecture at full camera frame rates (156 frames/second herein).
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Affiliation(s)
- Bin Yang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, Pittsburgh, PA, United States
| | - Po-Yi Lee
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Yi Hua
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Bryn Brazile
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Fengting Ji
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ziyi Zhu
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ian A Sigal
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States
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136
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Szeto J, Chow A, McCrea L, Mozzer A, Nguyen TD, Quigley HA, Pitha I. Regional Differences and Physiologic Behaviors in Peripapillary Scleral Fibroblasts. Invest Ophthalmol Vis Sci 2021; 62:27. [PMID: 33502460 PMCID: PMC7846956 DOI: 10.1167/iovs.62.1.27] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose The purpose of this study was to describe the cellular architecture of normal human peripapillary sclera (PPS) and evaluate surface topography's role in fibroblast behavior. Methods PPS cryosections from nonglaucomatous eyes were labelled for nuclei, fibrillar actin (FA), and alpha smooth muscle actin (αSMA) and imaged. Collagen fibrils were imaged using second harmonic generation. Nuclear density and aspect ratio of the internal PPS (iPPS), outer PPS (oPPS), and peripheral sclera were determined. FA and αSMA fibril alignment with collagen extracellular matrix (ECM) was determined. PPS fibroblasts were cultured on smooth or patterned membranes under mechanical strain and in the presence of TGFβ1 and 2. Results The iPPS (7.1 ± 2.0 × 10−4, P < 0.0001) and oPPS (5.3 ± 1.4 × 10−4, P = 0.0013) had greater nuclei density (nuclei/µm2) than peripheral sclera (2.5 ± 0.8 × 10−4). The iPPS (2.0 ± 0.3, P = 0.002) but not oPPS (2.4 ± 0.4, P = 0.45) nuclei had smaller aspect ratios than peripheral (2.7 ± 0.5) nuclei. FA was present throughout the scleral stroma and was more aligned with oPPS collagen (9.6 ± 1.9 degrees) than in the peripheral sclera (15.9 ± 3.9 degrees, P =0.002). The αSMA fibers in the peripheral sclera were less aligned with collagen fibrils (26.4 ± 4.8 degrees) than were FA (15.9 ± 3.9 degrees, P = 0.0002). PPS fibroblasts cultured on smooth membranes shifted to an orientation perpendicular to the direction of cyclic uniaxial strain (1 Hz, 5% strain, 42.2 ± 7.1 degrees versus 62.0 ± 8.5 degrees, P < 0.0001), whereas aligned fibroblasts on patterned membranes were resistant to strain-induced reorientation (5.9 ± 1.4 degrees versus 10 ± 3.3 degrees, P = 0.21). Resistance to re-orientation was reduced by TGFβ treatment (10 ± 3.3 degrees without TGFβ1 compared to 23.1 ± 4.5 degrees with TGFβ1, P < 0.0001). Conclusions Regions of the posterior sclera differ in cellular density and nuclear morphology. Topography alters the cellular response to mechanical strain.
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Affiliation(s)
- Julia Szeto
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Amanda Chow
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Liam McCrea
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Ann Mozzer
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Thao D Nguyen
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.,Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States
| | - Harry A Quigley
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.,Glaucoma Center of Excellence, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Ian Pitha
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.,Center for Nanomedicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.,Glaucoma Center of Excellence, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
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137
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Brown DM, Pardue MT, Ethier CR. A biphasic approach for characterizing tensile, compressive and hydraulic properties of the sclera. J R Soc Interface 2021; 18:20200634. [PMID: 33468024 PMCID: PMC7879763 DOI: 10.1098/rsif.2020.0634] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/15/2020] [Indexed: 11/12/2022] Open
Abstract
Measuring the biomechanical properties of the mouse sclera is of great interest: altered scleral properties are features of many common ocular pathologies, and the mouse is a powerful tool for studying genetic factors in disease, yet the small size of the mouse eye and its thin sclera make experimental measurements in the mouse difficult. Here, a poroelastic material model is used to analyse data from unconfined compression testing of both pig and mouse sclera, and the tensile modulus, compressive modulus and permeability of the sclera are obtained at three levels of compressive strain. Values for all three properties were comparable to previously reported values measured by tests specific for each property. The repeatability of the approach was evaluated using a test-retest experimental paradigm on pig sclera, and tensile stiffness and permeability measurements were found to be reasonably repeatable. The intrinsic material properties of the mouse sclera were measured for the first time. Tensile stiffness and permeability of the sclera in both species were seen to be dependent on the state of compressive strain. We conclude that unconfined compression testing of sclera, when analysed with poroelastic theory, is a powerful tool to phenotype mouse scleral changes in future genotype-phenotype association studies.
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Affiliation(s)
- Dillon M. Brown
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
- Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Machelle T. Pardue
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
- Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - C. Ross Ethier
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
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138
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Markov P, Hayes AJ, Zhu H, Boote C, Blain EJ. 3D immuno-confocal image reconstruction of fibroblast cytoskeleton and nucleus architecture. JOURNAL OF BIOPHOTONICS 2021; 14:e202000202. [PMID: 33038053 DOI: 10.1002/jbio.202000202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/28/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
Computational models of cellular structures generally rely on simplifying approximations and assumptions that limit biological accuracy. This study presents a comprehensive image processing pipeline for creating unified three-dimensional (3D) reconstructions of the cell cytoskeletal networks and nuclei. Confocal image stacks of these cellular structures were reconstructed to 3D isosurfaces (Imaris), then tessellations were simplified to reduce the number of elements in initial meshes by applying quadric edge collapse decimation with preserved topology boundaries (MeshLab). Geometries were remeshed to ensure uniformity (Instant Meshes) and the resulting 3D meshes exported (ABAQUS) for downstream application. The protocol has been applied successfully to fibroblast cytoskeletal reorganisation in the scleral connective tissue of the eye, under mechanical load that mimics internal eye pressure. While the method herein is specifically employed to reconstruct immunofluorescent confocal imaging data, it is also more widely applicable to other biological imaging modalities where accurate 3D cell structures are required.
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Affiliation(s)
- Petar Markov
- School of Biosciences, Cardiff University, Cardiff, Wales, UK
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
- School of Engineering, Cardiff University, Cardiff, Wales, UK
| | - Anthony J Hayes
- Bioimaging Research Hub, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Hanxing Zhu
- School of Engineering, Cardiff University, Cardiff, Wales, UK
| | - Craig Boote
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - Emma J Blain
- School of Biosciences, Cardiff University, Cardiff, Wales, UK
- Biomechanics and Bioengineering Centre Versus Arthritis, School of Biosciences, Cardiff University, Cardiff, Wales, UK
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139
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Qassim A, Mullany S, Abedi F, Marshall H, Hassall MM, Kolovos A, Knight LSW, Nguyen T, Awadalla MS, Chappell A, Schulz AM, Galanopoulos A, Agar A, Healey PR, Hewitt AW, Graham SL, Landers J, Casson RJ, Siggs OM, Craig JE. Corneal Stiffness Parameters Are Predictive of Structural and Functional Progression in Glaucoma Suspect Eyes. Ophthalmology 2020; 128:993-1004. [PMID: 33245936 DOI: 10.1016/j.ophtha.2020.11.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/28/2020] [Accepted: 11/18/2020] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes. DESIGN Prospective, longitudinal study. PARTICIPANTS Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results. METHODS Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures. MAIN OUTCOME MEASURES Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing. RESULTS Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P = 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 μm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17-1.28; P = 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 μm/year (95% CI, 1.4-6.1; P = 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P = 0.002), synergistic with thinner CCT (P = 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3-10.5; P = 0.014). CONCLUSIONS Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression.
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Affiliation(s)
- Ayub Qassim
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia.
| | - Sean Mullany
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Farshad Abedi
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Henry Marshall
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Mark M Hassall
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Antonia Kolovos
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Lachlan S W Knight
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Thi Nguyen
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Mona S Awadalla
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Angela Chappell
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Angela M Schulz
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Anna Galanopoulos
- South Australian Institute of Ophthalmology, Royal Adelaide Hospital, Adelaide, Australia
| | - Ashish Agar
- Department of Ophthalmology, Prince of Wales Hospital, Randwick, Australia
| | - Paul R Healey
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - John Landers
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Robert J Casson
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, Australia
| | - Owen M Siggs
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Jamie E Craig
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
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Willemse J, Gräfe MGO, Verbraak FD, de Boer JF. In Vivo 3D Determination of Peripapillary Scleral and Retinal Layer Architecture Using Polarization-Sensitive Optical Coherence Tomography. Transl Vis Sci Technol 2020; 9:21. [PMID: 33150047 PMCID: PMC7585391 DOI: 10.1167/tvst.9.11.21] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/25/2020] [Indexed: 12/24/2022] Open
Abstract
Purpose The purpose of this paper was to determine the architecture of the collagen fibers of the peripapillary sclera, the retinal nerve fiber layer (RNFL), and Henle's fiber layer in vivo in 3D using polarization-sensitive optical coherence tomography (PS-OCT). Methods Seven healthy volunteers were imaged with our in-house built PS-OCT system. PS-OCT imaging included intensity, local phase retardation, relative optic axis, and optic axis uniformity (OAxU). Differential Mueller matrix calculus was used for the first time in ocular tissues to visualize local orientations that varied with depth, incorporating a correction method for the fiber orientation in preceding layers. Results Scleral collagen fiber orientation images clearly showed an inner layer with an orientation parallel to the RNFL orientation, and a deeper layer where the collagen was circularly oriented. RNFL orientation images visualized the nerve fibers leaving the optic nerve head (ONH) in a radial pattern. The phase retardation and orientation of Henle's fiber layer were visualized locally for the first time. Conclusions PS-OCT successfully showed the orientation of the retinal nerve fibers, sclera, and Henle's fiber layer, and is to the extent of our knowledge the only technique able to do so in 3D in vivo. Translational Relevance In vivo 3D imaging of scleral collagen architecture and the retinal neural fibrous structures can improve our understanding of retinal biomechanics and structural alterations in different disease stages of myopia and glaucoma.
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Affiliation(s)
- Joy Willemse
- Department of Physics and Astronomy, LaserLab Amsterdam, Vrije Universiteit de Boelelaan, Amsterdam, The Netherlands
| | - Maximilian G O Gräfe
- Department of Physics and Astronomy, LaserLab Amsterdam, Vrije Universiteit de Boelelaan, Amsterdam, The Netherlands.,Current address: Imedos Systems GmbH, Am Nasstal 4, Jena, Germany
| | - Frank D Verbraak
- Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Ophthalmology Department, de Boelelaan, Amsterdam, The Netherlands
| | - Johannes F de Boer
- Department of Physics and Astronomy, LaserLab Amsterdam, Vrije Universiteit de Boelelaan, Amsterdam, The Netherlands.,Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Ophthalmology Department, de Boelelaan, Amsterdam, The Netherlands
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141
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Iomdina EN, Tikhomirova NK, Bessmertny AM, Serebryakova MV, Baksheeva VE, Zalevsky AO, Kotelin VI, Kiseleva OA, Kosakyan SM, Zamyatnin AA, Philippov PP, Zernii EY. Alterations in proteome of human sclera associated with primary open-angle glaucoma involve proteins participating in regulation of the extracellular matrix. Mol Vis 2020; 26:623-640. [PMID: 32913388 PMCID: PMC7479071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/31/2020] [Indexed: 11/14/2022] Open
Abstract
Purpose Primary open-angle glaucoma (POAG) is a common ocular disease, associated with abnormalities in aqueous humor circulation and an increase in intraocular pressure (IOP), leading to progressive optical neuropathy and loss of vision. POAG pathogenesis includes alterations of the structural properties of the sclera, especially in the optic nerve head area, contributing to the degeneration of the retinal ganglion cells. Abnormal sclera biomechanics hinder adequate compensation of IOP fluctuations, thus aggravating POAG progression. The proteomic basis of biomechanical disorders in glaucomatous sclera remains poorly understood. This study is aimed at revealing alterations in major scleral proteins, associated with POAG, at different stages of the disease and with different IOP conditions. Methods Samples of sclera were collected from 67 patients with POAG during non-penetrating deep sclerectomy and from nine individuals without POAG. Scleral proteins were extracted with a strong lysis buffer, containing a combination of an ionic detergent, a chaotropic agent, and a disulfide reducing agent, and were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The major scleral proteins were selected, subjected to in-gel digestion, and identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF)/TOF mass spectrometry (MS), coupled with tandem mass spectrometry (MS/MS). The specific POAG-associated alterations of the selected proteins were analyzed with SDS-PAGE and confirmed with western blotting of the scleral extracts, using the respective antibodies. The group of POAG-associated proteins was analyzed using Gene Ontology and genome-wide association study enrichment and protein-protein interaction network prediction. Results A total of 11 proteins were identified, among which six proteins, namely, vimentin, angiopoietin-related protein 7, annexin A2, serum amyloid P component, serum albumin, and thrombospondin-4, were found to be upregulated in the sclera of patients with advanced and terminal POAG. In the early stages of the disease, thrombospondin-4 level was, on the contrary, reduced when compared with the control, whereas the concentration of vimentin varied, depending on the IOP level. Moreover, angiopoietin-related protein 7 manifested as two forms, exhibiting opposite behavior: The common 45 kDa form grew with the progression of POAG, whereas the 35 kDa (apparently non-glycosylated) form was absent in the control samples, appeared in patients with early POAG, and decreased in concentration over the course of the disease. Functional bioinformatics analysis linked the POAG-associated proteins with IOP alterations and predicted their secretion into extracellular space and their association with extracellular vesicles and a collagen-containing extracellular matrix. Conclusions POAG is accompanied by alterations of the scleral proteome, which represent a novel hallmark of the disease and can reflect pathological changes in scleral biochemistry and biomechanics. The potential mechanisms underlying these changes relate mainly to the structure of the extracellular matrix, protein glycosylation, and calcium binding, and may involve fibroblast cytoskeleton regulation, as well as oxidative and inflammatory responses.
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Affiliation(s)
- Elena N. Iomdina
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Natalya K. Tikhomirova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | - Marina V. Serebryakova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Viktoriia E. Baksheeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Arthur O. Zalevsky
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia,Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | | | - Olga A. Kiseleva
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Sbrui M. Kosakyan
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - Andrey A. Zamyatnin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Pavel P. Philippov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Evgeni Yu. Zernii
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
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142
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Wang B, Hua Y, Brazile BL, Yang B, Sigal IA. Collagen fiber interweaving is central to sclera stiffness. Acta Biomater 2020; 113:429-437. [PMID: 32585309 DOI: 10.1016/j.actbio.2020.06.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/01/2020] [Accepted: 06/15/2020] [Indexed: 12/27/2022]
Abstract
The mechanical properties of the microstructural components of sclera are central to eye physiology and pathology. Because these parameters are extremely difficult to measure directly, they are often estimated using inverse-modeling matching deformations of macroscopic samples measured experimentally. Although studies of sclera microstructure show collagen fiber interweaving, current models do not account for this interweaving or the resulting fiber-fiber interactions, which might affect parameter estimates. Our goal was to test the hypothesis that constitutive parameters estimated using inverse modeling differ if models account for fiber interweaving and interactions. We developed models with non-interweaving or interweaving fibers over a wide range of volume fractions (36-91%). For each model, we estimated fiber stiffness using inverse modeling matching biaxial experimental data of human sclera. We found that interweaving increased the estimated fiber stiffness. When the collagen volume fraction was 64% or less, the stiffness of interweaving fibers was about 1.25 times that of non-interweaving fibers. For higher volume fractions, the ratio increased substantially, reaching 1.88 for a collagen volume fraction of 91%. Simulating a model (interweaving/non-interweaving) using the fiber stiffness estimated from the other model produced substantially different behavior, far from that observed experimentally. These results show that estimating microstructural component mechanical properties is highly sensitive to the assumed interwoven/non-interwoven architecture. Moreover, the results suggest that interweaving plays an important role in determining the structural stiffness of sclera, and potentially of other soft tissues in which the collagen fibers interweave. STATEMENT OF SIGNIFICANCE: The collagen fibers of sclera are interwoven, but numerical models do not account for this interweaving or the resulting fiber-fiber interactions. To determine if interweaving matters, we examined the differences in the constitutive model parameters estimated using inverse modeling between models with interweaving and non-interweaving fibers. We found that the estimated stiffness of the interweaving fibers was up to 1.88 times that of non-interweaving fibers, and that the estimate increased with collagen volume fraction. Our results suggest that fiber interweaving is a fundamental characteristic of connective tissues, additional to anisotropy, density and orientation. Better characterization of interweaving, and of its mechanical effects is likely central to understanding microstructure and biomechanics of sclera and other soft tissues.
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Role of radially aligned scleral collagen fibers in optic nerve head biomechanics. Exp Eye Res 2020; 199:108188. [PMID: 32805265 DOI: 10.1016/j.exer.2020.108188] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/22/2020] [Accepted: 08/06/2020] [Indexed: 01/04/2023]
Abstract
Collagen fibers organized circumferentially around the canal in the peripapillary sclera are thought to provide biomechanical support to the sensitive tissues within the optic nerve head (ONH). Recent studies have demonstrated the existence of a family of fibers in the innermost sclera organized radially from the scleral canal. Our goal was to determine the role of these radial fibers in the sensitivity of scleral canal biomechanics to acute increases in intraocular pressure (IOP). Following the same general approach of previous parametric sensitivity studies, we created nonlinear generic finite element models of a posterior pole with various combinations of radial and circumferential fibers at an IOP of 0 mmHg. We then simulated the effects of normal and elevated IOP levels (15 and 30 mmHg). We monitored four IOP-induced geometric changes: peripapillary sclera stretch, scleral canal displacement, lamina cribrosa displacement, and scleral canal expansion. In addition, we examined the radial (maximum tension) and through-thickness (maximum compression) strains within the ONH tissues. Our models predicted that: 1) radial fibers reduced the posterior displacement of the lamina, especially at elevated IOP; 2) radial fibers reduced IOP-induced radial strain within the peripapillary sclera and retinal tissue; and 3) a combination of radial and circumferential fibers maintained strains within the ONH at a level similar to those conferred by circumferential fibers alone. In conclusion, radial fibers provide support for the posterior globe, additional to that provided by circumferential fibers. Most importantly, a combination of both fiber families can better protect ONH tissues from excessive IOP-induced deformation than either alone.
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Zhang X, Li S, Tang Y, Guo Y, Gao S. Intractable Ocular Diseases and Treatment Progress. AAPS PharmSciTech 2020; 21:236. [PMID: 32803351 DOI: 10.1208/s12249-020-01774-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
In recent years, with the aging of the population and the frequent use of electronic devices, many eye diseases have shown a linear upward trend, such as dry eye disease, glaucoma, cataract, age-related macular degeneration, and diabetic retinopathy. These diseases are often chronic and difficult to cure. Based on the structure and barrier of the human eye, this review describes the pathogenesis and treatments of several intractable eye diseases and summarizes the advanced ocular drug delivery systems to provide new treatment ideas for these diseases. Finally, we also look forward to the prospect of RNAi therapy in the treatment of eye diseases.
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Association between MMP/TIMP Levels in the Aqueous Humor and Plasma with Axial Lengths in Myopia Patients. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2961742. [PMID: 32596291 PMCID: PMC7305534 DOI: 10.1155/2020/2961742] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 05/29/2020] [Indexed: 01/24/2023]
Abstract
Purpose The present study investigated the profiles of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) of the aqueous humor (AH) and plasma (PL) in myopia patients, to determine whether there was an association between these levels with their axial length (AL) and to investigate if MMPs/TIMPs were regulated locally or systemically. Methods A cross-sectional study was conducted. Thirty-nine patients (78 eyes) diagnosed with high myopia were recruited. The AL was measured using IOL Master. And the patients were divided into three groups based on their AL, Group A (AL ≤ 26 mm), Group B (26 < AL ≤ 28 mm), and Group C (AL > 28 mm). The AH in both eyes and blood samples were collected before the patients underwent implantable collamer lens surgery. In all, 78 samples of the AH and 39 samples of the PL were analyzed using MILLIPLEX map assays, followed by statistical analyses of the results. Results There were 8 patients (16 eyes) in Group A, 22 patients (44 eyes) in Group B, and 9 patients (18 eyes) in Group C. MMP-1 (p = 0.014, Β = 0.118), MMP-2 (p ≤ 0.001, Β = 0.278), MMP-9 (p ≤ 0.001, Β = 0.019), and TIMP-1 (p = 0.014, Β = 0.062) in the AH were positively associated with the AL. MMP-1 (p = 0.004, Β = 0.001) and TIMP-1 (p = 0.030, Β = 1.171) concentrations in the PL increased linearly with longer ALs. No concentration-dependent relationship was found between MMP-2 in the PL and AL. Conclusions There was a consistent relationship between MMP-2 in the AH and AL. AL was not consistently or substantially affected by MMP-2 in the PL, indicating myopia formation was possibly a localized process. Associations among MMP-1, MMP-9, and TIMP-1 in the AH and AL were also observed.
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Pardon LP, Harwerth RS, Patel NB. Neuroretinal rim response to transient changes in intraocular pressure in healthy non-human primate eyes. Exp Eye Res 2020; 193:107978. [PMID: 32081667 DOI: 10.1016/j.exer.2020.107978] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/26/2020] [Accepted: 02/14/2020] [Indexed: 12/19/2022]
Abstract
Optic nerve head (ONH) neuroretinal rim thickness, quantified as minimum rim width (BMO-MRW), is a sensitive measure for assessing early glaucomatous disease. The BMO-MRW is sensitive to transient fluctuations in intraocular pressure (IOP), but the time course over which BMO-MRW decreases and recovers with changes in IOP remains unknown. The goal of this study was to investigate the dynamics of BMO-MRW changes over 2-h periods of mild or moderate IOP elevation, and subsequent recovery, in healthy non-human primate eyes. Eight non-human primates were included in the study. For each animal, in two different sessions separated by at least 2 weeks, the anterior chamber IOP of one eye was maintained at either 25 mmHg or 40 mmHg for 2 h and, subsequently, at 10 mmHg for 2 h. For the duration of anterior chamber cannulation, optical coherence tomography (OCT) radial scans centered on the ONH were acquired every 5 min and used to quantify BMO-MRW. An exponential decay or rise to maximum function was used to determine the extent and rate of structural change. Additionally, Bruch's membrane opening (BMO) area, BMO height/displacement, and BMO-referenced anterior lamina cribrosa surface depth (BMO-ALCSD) were computed from radial scans. A circular scan was used to quantify retinal nerve fiber layer thickness (RNFLT) and circumpapillary choroid thickness. The primary results demonstrated that the BMO-MRW changed over an extended duration, while BMO displacement was rapid and remained stable with sustained IOP. The mean maximum predicted BMO-MRW thinning following 2 h of IOP elevation was significantly related to pressure (34.2 ± 13.8 μm for an IOP of 25 mmHg vs 40.5 ± 12.6 μm for 40 mmHg, p = 0.03). The half-life for BMO-MRW thinning was 21.9 ± 9.2 min for 25 mmHg and 20.9 ± 4.2 min for 40 mmHg, not significantly different between IOP levels (p = 0.76). Subsequently, after 2 h of IOP at 10 mmHg, all animals exhibited partial recovery of BMO-MRW with similar degrees of persistent residual thinning for the two IOP levels (21.5 ± 13.7 vs 21.0 ± 12.3 μm, p = 0.88). Similar to BMO-MRW, choroid thickness exhibited gradual thinning with IOP elevation and residual thinning following IOP reduction. However, there was no significant change in BMO area or BMO-ALCSD in either experimental session. The RNFLT gradually decreased over the duration of IOP elevation, with continued decreases following IOP reduction for the 40 mmHg session, resulting in total changes from baseline of -2.24 ± 0.81 and -2.45 ± 1.21 μm for 25 and 40 mmHg, respectively (p < 0.001). The sum of the results demonstrate that the ONH neural tissue is sensitive to changes in IOP, the effects of which are gradual over an extended time course and different for increased vs. decreased pressure. Understanding the duration over which IOP influences BMO-MRW has important implications for studies investigating the effects of IOP on the ONH. Additionally, individual variability in ONH response to IOP may improve our understanding of the risk and progression of disease.
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Affiliation(s)
- Laura P Pardon
- University of Houston, College of Optometry, 4901 Calhoun Road, Houston, TX, 77204-2020, USA.
| | - Ronald S Harwerth
- University of Houston, College of Optometry, 4901 Calhoun Road, Houston, TX, 77204-2020, USA
| | - Nimesh B Patel
- University of Houston, College of Optometry, 4901 Calhoun Road, Houston, TX, 77204-2020, USA
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