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Ramm L, Spoerl E, Terai N, Herber R, Pillunat LE. Association Between Corneal Changes and Retinal Oximetry in Diabetes Mellitus. Clin Ophthalmol 2024; 18:1235-1243. [PMID: 38737594 PMCID: PMC11088381 DOI: 10.2147/opth.s456020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/21/2024] [Indexed: 05/14/2024] Open
Abstract
Purpose Diabetes mellitus (DM) causes different corneal changes that are associated with the severity of diabetic retinopathy. To identify the pathophysiological reasons for this, corneal tomography and optical densitometry (COD) were combined with retinal oximetry. Methods Patients with DM and healthy subjects were included in this pilot study. Spatially resolved corneal thickness and COD were assessed using the Pentacam HR (Oculus). The pachymetry difference (PACDiff) was calculated as an indicator of an increase in the peripheral corneal thickness. Oxygen saturation (SO2) of the retinal vessels was measured using the Retinal Vessel Analyzer (Imedos Systems UG). Subsequently, the associations between corneal and retinal parameters were analyzed. Results Data from 30 patients with DM were compared with those from 30 age-matched healthy subjects. In DM, arterial (P = 0.048) and venous (P < 0.001) SO2 levels were increased, and arteriovenous SO2 difference was decreased (P < 0.001). In patients, PACDiff was higher than that in healthy subjects (P < 0.05), indicating a stronger increase in peripheral corneal thickness. The COD was reduced in DM (P = 0.004). The PACDiff of concentric rings with a diameter of 4 mm (r = -0.404; P = 0.033) to 8 mm (r = -0.522; P = 0.004) was inversely correlated with the arteriovenous SO2 difference. Furthermore, PACDiff 4 mm was negatively associated with arterial SO2 (r = -0.389; P = 0.041), and the COD of the peripheral corneal areas correlated positive with arterial SO2 (COD total 10-12 mm: r = 0.408; P = 0.025). Conclusion These associations might indicate a common pathogenesis of corneal and retinal changes in DM, which could be caused by reduced oxygen supply, mitochondrial dysfunction, oxidative stress, and cytokine effects.
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Affiliation(s)
- Lisa Ramm
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Eberhard Spoerl
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Naim Terai
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Robert Herber
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Lutz E Pillunat
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
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Passaro ML, Airaldi M, Ancona C, Cucco R, Costagliola C, Semeraro F, Romano V. Comparative Analysis of Tomographic Indicators Forecasting Decompensation in Fuchs Endothelial Corneal Dystrophy. Cornea 2024:00003226-990000000-00512. [PMID: 38471010 DOI: 10.1097/ico.0000000000003521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/23/2024] [Indexed: 03/14/2024]
Abstract
PURPOSE To compare the performance of 3 commercially available tomographers (the Pentacam Scheimpflug camera, the swept-source optical coherence tomography Casia, and the blue light slit-scanning tomographer Precisio) in the identification of patterns associated with Fuchs endothelial corneal dystrophy (FECD) decompensation. METHODS This was a clinic-based cross-sectional imaging study. Pachymetry maps and posterior surface elevation maps were acquired with the 3 devices from 61 eyes affected by FECD. The maps were graded according to the evidence of tomographic patterns predictive of FECD decompensation (loss of parallel isopachs, displacement of the thinnest point, and focal posterior depression) by 2 blind cornea specialists. RESULTS The loss of parallel isopachs was significantly less frequently evident in Pentacam pachymetry maps [8%, 95% confidence interval (CI) (3%, 18%)] compared with both the Casia [31%, 95% CI (20%, 44%), P = 0.01] and Precisio devices [24%, 95% CI (15%, 37%), P = 0.05]. The displacement of the thinnest point was graded as most evident in a significantly higher proportion of Precisio pachymetry maps [43%, 95% CI (31%, 55%)] compared with both the Pentacam [13%, 95% CI (6%, 24%), P = 0.001] and Casia devices [21%, 95% CI (12%, 33%), P = 0.03]. There were no significant differences in the identification of focal posterior depression on posterior elevation maps across the 3 devices. CONCLUSIONS Identification of patterns predictive of FECD prognosis on pachymetry and posterior elevation maps is possible with different devices. However, their evidence varies across tomographers, and the results from different devices are not interchangeable.
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Affiliation(s)
- Maria Laura Passaro
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", Naples, Italy
| | - Matteo Airaldi
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
- St. Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom; and
| | - Chiara Ancona
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
| | - Rosangela Cucco
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
| | - Ciro Costagliola
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", Naples, Italy
| | - Francesco Semeraro
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
| | - Vito Romano
- St. Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom; and
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
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Boix-Lemonche G, Hildebrand T, Haugen HJ, Petrovski G, Nogueira LP. Contrast-enhanced Micro-CT 3D visualization of cell distribution in hydrated human cornea. Heliyon 2024; 10:e25828. [PMID: 38356495 PMCID: PMC10865036 DOI: 10.1016/j.heliyon.2024.e25828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/27/2024] [Accepted: 02/02/2024] [Indexed: 02/16/2024] Open
Abstract
Background The cornea, a vital component of the human eye, plays a crucial role in maintaining visual clarity. Understanding its ultrastructural organization and cell distribution is fundamental for elucidating corneal physiology and pathology. This study comprehensively examines the microarchitecture of the hydrated human cornea using contrast-enhanced micro-computed tomography (micro-CT). Method Fresh human corneal specimens were carefully prepared and hydrated to mimic their in vivo state. Contrast enhancement with Lugol's iodine-enabled high-resolution Micro-CT imaging. The cells' three-dimensional (3D) distribution within the cornea was reconstructed and analyzed. Results The micro-CT imaging revealed exquisite details of the corneal ultrastructure, including the spatial arrangement of cells throughout its depth. This novel approach allowed for the visualization of cells' density and distribution in different corneal layers. Notably, our findings highlighted variations in cell distribution between non-hydrated and hydrated corneas. Conclusions This study demonstrates the potential of contrast-enhanced micro-CT as a valuable tool for non-destructive, 3D visualization and quantitative analysis of cell distribution in hydrated human corneas. These insights contribute to a better understanding of corneal physiology and may have implications for research in corneal diseases and tissue engineering.
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Affiliation(s)
- Gerard Boix-Lemonche
- Center for Eye Research and Innovative Diagnostics, Department of Ophthalmology, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Norway
| | | | | | - Goran Petrovski
- Center for Eye Research and Innovative Diagnostics, Department of Ophthalmology, Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Norway
- Department of Ophthalmology, and Norwegian Center for Stem Cell Research, Oslo University Hospital, Oslo, Norway
- Department of Ophthalmology, University of Split School of Medicine and University Hospital Centre, Split, Croatia
- UKLO Network, University St. Kliment Ohridski – Bitola, Bitola, Macedonia
| | - Liebert Parreiras Nogueira
- Oral Research Laboratory, Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway
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Huertas-Bello M, Seery CW, Sem K, Fout E, Triglia C, Eghrari AO, Koo EH. Effect of Anterior Chamber Air on Central Corneal Thickness in Human Donor Eyes. Cornea 2023:00003226-990000000-00439. [PMID: 38128101 DOI: 10.1097/ico.0000000000003457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023]
Abstract
PURPOSE The purpose of this study was to describe the effects of intracameral air on corneal edema. METHODS A laboratory investigation was performed on human donor corneas. Baseline pachymetry measurements through anterior segment optical coherence tomography and endothelial cell density were obtained for all corneas. Each pair of corneas was separated and randomly assigned to undergo air injection or Optisol-GS into a BIONIKO artificial anterior chamber for 5 minutes at physiologic intraocular pressure confirmed by digital palpation. Photographs were obtained immediately on connection of the cornea to the artificial anterior chamber and on completion of the 5 minutes of treatment, with anterior chamber air being exchanged for Optisol-GS. Pretreatment and posttreatment photographs were obtained. Immediately after treatment, pachymetry was again obtained on all corneas. Pachymetry data underwent statistical analysis. RESULTS Corneal pachymetry improved from 690.5 ± 126.6 to 576.1 ± 87.2 μm, yielding a 114.4 ± 50.4 μm improvement of pachymetry in the group with air injected into the anterior chamber. This was a significant improvement of pachymetry when compared with the group with Optisol-GS injected into the anterior chamber, which showed an improvement from 662.3 ± 126.5 to 613.5 ± 108.0 μm, yielding an improvement of 48.8 ± 34.3 μm. CONCLUSIONS Injection of air into the anterior chamber leads to a significant decrease in corneal pachymetry. We thereby propose that injecting air intracamerally is an effective intraoperative intervention when visualization is negatively affected by corneal edema.
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Affiliation(s)
- Marcela Huertas-Bello
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
| | - Christopher W Seery
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
| | - Karen Sem
- University of Florida College of Medicine, Gainesville, FL
| | | | | | - Allen O Eghrari
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ellen H Koo
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
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Nambiar MH, Seiler TG, Senti S, Liechti L, Müller F, Studer H, Roy AS, Büchler P. Depth-dependent mechanical properties of the human cornea by uniaxial extension. Exp Eye Res 2023; 237:109718. [PMID: 37952725 DOI: 10.1016/j.exer.2023.109718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/13/2023] [Accepted: 11/06/2023] [Indexed: 11/14/2023]
Abstract
The purpose of this study was to investigate the depth-dependent biomechanical properties of the human corneal stroma under uniaxial tensile loading. Human stroma samples were obtained after the removal of Descemet's membrane in the course of Descemet's membrane endothelial keratoplasty (DMEK) transplantation. Uniaxial tensile tests were performed at three different depths: anterior, central, and posterior on 2 × 6 × 0.15 mm strips taken from the central DMEK graft. The measured force-displacement data were used to calculate stress-strain curves and to derive the tangent modulus. The study showed that mechanical strength decreased significantly with depth. The anterior cornea appeared to be the stiffest, with a stiffness approximately 18% higher than that of the central cornea and approximately 38% higher than that of the posterior layer. Larger variations in mechanical response were observed in the posterior group, probably due to the higher degree of alignment of the collagen fibers in the posterior sections of the cornea. This study contributes to a better understanding of the biomechanical tensile properties of the cornea, which has important implications for the development of new treatment strategies for corneal diseases. Accurate quantification of tensile strength as a function of depth is critical information that is lacking in human corneal biomechanics to develop numerical models and new treatment methods.
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Affiliation(s)
- Malavika H Nambiar
- ARTORG Center for Biomedical Engineering Research, University of Bern, Freiburgstrasse 3, 3010, Bern, Switzerland.
| | - Theo G Seiler
- IROC AG, Institut für Refraktive und Ophthalmo-Chirurgie, Stockerstrasse 37, 8002, Zürich, Switzerland; Universitätsklinik für Augenheilkunde, Inselspital Bern, Freiburgstrasse 15, 3010, Bern, Switzerland; Klinik für Augenheilkunde, Universitätsklinikum Düsseldorf, Moorenstr, 540225, Düsseldorf, Germany.
| | - Sebastian Senti
- ARTORG Center for Biomedical Engineering Research, University of Bern, Freiburgstrasse 3, 3010, Bern, Switzerland.
| | - Layko Liechti
- Ziemer Ophthalmic Systems AG, Allmendstrasse 11, 2562, Port, Switzerland.
| | - Fabian Müller
- Ziemer Ophthalmic Systems AG, Allmendstrasse 11, 2562, Port, Switzerland.
| | - Harald Studer
- Optimo Medical, Robert-Walser-Platz 7, 2503, Biel, Switzerland.
| | - Abhijit S Roy
- Narayana Nethralaya Eye Clinic, Bengaluru, Karnataka, 560010, India.
| | - Philippe Büchler
- ARTORG Center for Biomedical Engineering Research, University of Bern, Freiburgstrasse 3, 3010, Bern, Switzerland.
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Xeroudaki M, Rafat M, Moustardas P, Mukwaya A, Tabe S, Bellisario M, Peebo B, Lagali N. A double-crosslinked nanocellulose-reinforced dexamethasone-loaded collagen hydrogel for corneal application and sustained anti-inflammatory activity. Acta Biomater 2023; 172:234-248. [PMID: 37866722 DOI: 10.1016/j.actbio.2023.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 09/29/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
In cases of blinding disease or trauma, hydrogels have been proposed as scaffolds for corneal regeneration and vehicles for ocular drug delivery. Restoration of corneal transparency, augmenting a thin cornea and postoperative drug delivery are particularly challenging in resource-limited regions where drug availability and patient compliance may be suboptimal. Here, we report a bioengineered hydrogel based on porcine skin collagen as an alternative to human donor corneal tissue for applications where long-term stability of the hydrogel is required. The hydrogel is reinforced with cellulose nanofibers extracted from the Ciona intestinalis sea invertebrate followed by double chemical and photochemical crosslinking. The hydrogel is additionally loaded with dexamethasone to provide sustained anti-inflammatory activity. The reinforced double-crosslinked hydrogel after drug loading maintained high optical transparency with significantly improved mechanical characteristics compared to non-reinforced hydrogels, while supporting a gradual sustained drug release for 60 days in vitro. Dexamethasone, after exposure to crosslinking and sterilization procedures used in hydrogel production, inhibited tube formation and cell migration of TNFα-stimulated vascular endothelial cells. The drug-loaded hydrogels suppressed key pro-inflammatory cytokines CCL2 and CXCL5 in TNFα-stimulated human corneal epithelial cells. Eight weeks after intra-stromal implantation in the cornea of 12 New-Zealand white rabbits subjected to an inflammatory suture stimulus, the dexamethasone-releasing hydrogels suppressed TNFα, MMP-9, and leukocyte and fibroblast cell invasion, resulting in reduced corneal haze, sustained corneal thickness and stromal morphology, and reduced overall vessel invasion. This collagen-nanocellulose double-crosslinked hydrogel can be implanted to treat corneal stromal disease while suppressing inflammation and maintaining transparency after corneal transplantation. STATEMENT OF SIGNIFICANCE: To treat blinding diseases, hydrogel scaffolds have been proposed to facilitate corneal restoration and ocular drug delivery. Here, we improve on a clinically tested collagen-based scaffold to improve mechanical robustness and enzymatic resistance by incorporating sustainably sourced nanocellulose and dual chemical-photochemical crosslinking to reinforce the scaffold, while simultaneously achieving sustained release of an incorporated anti-inflammatory drug, dexamethasone. Evaluated in the context of a corneal disease model with inflammation, the drug-releasing nanocellulose-reinforced collagen scaffold maintained the cornea's transparency and resisted degradation while suppressing inflammation postoperatively. This biomaterial could therefore potentially be applied in a wider range of sight-threatening diseases, overcoming suboptimal administration of postoperative medications to maintain hydrogel integrity and good vision.
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Affiliation(s)
- Maria Xeroudaki
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Mehrdad Rafat
- NaturaLens AB, Linköping, Sweden; LinkoCare Life Sciences AB, Linköping, Sweden; Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Petros Moustardas
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Anthony Mukwaya
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Shideh Tabe
- NaturaLens AB, Linköping, Sweden; LinkoCare Life Sciences AB, Linköping, Sweden
| | - Marco Bellisario
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Beatrice Peebo
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Memira Eye Center Scandinavia, Solna, Sweden
| | - Neil Lagali
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway.
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Syed ZA, Milman T, Fertala J, Steplewski A, Fertala A. Corneal Wound Healing in the Presence of Antifibrotic Antibody Targeting Collagen Fibrillogenesis: A Pilot Study. Int J Mol Sci 2023; 24:13438. [PMID: 37686240 PMCID: PMC10488077 DOI: 10.3390/ijms241713438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/16/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
Highly organized collagen fibrils interlacing with proteoglycans form the crucial architecture of the cornea and facilitate its transparency. Corneal scarring from accidental injury, surgery, or infection alters this highly organized tissue, causing severe consequences, including blindness. There are no pharmacological or surgical methods to effectively and safely treat excessive corneal scarring. Thus, we tested the anticorneal scarring utility of a rationally designed anticollagen antibody (ACA) whose antifibrotic effects have already been demonstrated in nonocular models. Utilizing a rabbit model with an incisional corneal wound, we analyzed ACA's effects on forming collagen and proteoglycan-rich extracellular matrices in scar neotissue. We used microscopic and spectroscopic techniques to quantify these components and measure crucial parameters characterizing the structure and organization of collagen fibrils. Moreover, we analyzed the spatial distribution of collagen and proteoglycans in normal and healing corneas. Our study demonstrated significant changes in the quality and quantity of the analyzed molecules synthesized in scar neotissue. It showed that these changes extend beyond incision margins. It also showed ACA's positive impact on some crucial parameters defining proper cornea structure. This pilot study provides a stepping stone for future tests of therapeutic approaches that target corneal extracellular scar matrix assembly.
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Affiliation(s)
- Zeba A. Syed
- Wills Eye Hospital, Philadelphia, PA 19107, USA; (Z.A.S.); (T.M.)
| | - Tatyana Milman
- Wills Eye Hospital, Philadelphia, PA 19107, USA; (Z.A.S.); (T.M.)
| | - Jolanta Fertala
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Curtis Building, Room 501, 1015 Walnut Street, Philadelphia, PA 19107, USA; (J.F.); (A.S.)
| | - Andrzej Steplewski
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Curtis Building, Room 501, 1015 Walnut Street, Philadelphia, PA 19107, USA; (J.F.); (A.S.)
| | - Andrzej Fertala
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Curtis Building, Room 501, 1015 Walnut Street, Philadelphia, PA 19107, USA; (J.F.); (A.S.)
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Congenital Corneal Opacity in 22q11.2 Deletion Syndrome: A Case Series. Cornea 2023; 42:344-350. [PMID: 36455075 DOI: 10.1097/ico.0000000000003155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/14/2022] [Indexed: 12/02/2022]
Abstract
PURPOSE The purpose of this study was to describe the deep phenotype of congenital corneal opacities (CCO) in patients with 22q11.2 deletion syndrome (22q11.2 DS) and to identify putative regions or genes that could explain the CCO. METHODS A retrospective chart review was conducted to identify patients with 22q11.2 DS seen in the ophthalmology clinic of a tertiary referral children's hospital. Thirty patients were identified, with molecular confirmation. Twenty-six did not show structural anterior segment anomalies aside from posterior embryotoxon (n = 4), whereas 4 had bilateral CCO, of which 3 had preoperative images. We reviewed medical, operative, and pathology reports; anterior segment optical coherence tomography; high-frequency ultrasound; histopathologic slides; and genetic testing. To identify putative genes responsible for CCO, chromosomal breakpoints in patients with and without CCO were compared. RESULTS In the 3 patients with preoperative imaging and CCO, a pattern of paracentral corneal opacification with central clearing accompanied by iridocorneal or keratolenticular adhesions was observed. Anterior segment optical coherence tomography and histopathologic images showed central stromal thinning with a residual structure consistent with Descemet membrane. One patient presented at birth with unilateral corneal perforation, suggestive of likely stromal thinning. A comparison of the breakpoints across all cases failed to reveal unique regions or genes in patients with CCO. CONCLUSIONS 22q11.2 DS can rarely be associated with CCO. We describe a consistent pattern of central clearing related to posterior stromal thinning, with or without ICA/KLA. Possible candidate genes for corneal opacification in 22q11.2 DS remain elusive.
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Anitua E, Muruzabal F, de la Fuente M, Merayo-Lloves J, Alkhraisat MH. Development of a new plasma rich in growth factors membrane with improved optical properties. Ann Anat 2023; 248:152071. [PMID: 36801366 DOI: 10.1016/j.aanat.2023.152071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/07/2023] [Accepted: 02/07/2023] [Indexed: 02/18/2023]
Abstract
PURPOSE The aim of the present work was to develop a fibrin membrane using plasma rich in growth factors (PRGF) technology with improved optical properties to be used for the treatment of ocular surface diseases. BASIC PROCEDURES Blood was drawn from three healthy donors, and the volume of PRGF obtained from each donor was divided into two main groups: i) PRGF or ii) platelet-poor plasma (PPP). Each membrane was then used pure or diluted to 90 %, 80 %, 70 %, 60 % and 50 %. The transparency of each of the different membranes was evaluated. The degradation and morphological characterization of each membrane was also performed. Finally, a stability study of the different fibrin membranes was performed. MAIN FINDINGS The transmittance test showed that the fibrin membrane with the best optical characteristics was obtained after removal of platelets and dilution of fibrin to 50 % (50 % PPP). No significant differences (p > 0.05) were observed between the different membranes in the fibrin degradation test. The stability test showed that the membrane at 50 % PPP retains its optical and physical characteristics after storage at - 20 °C for 1 month compared to storage at 4 °C. PRINCIPAL CONCLUSIONS The present study describes the development and characterization of a new fibrin membrane with improved optical characteristics while maintaining mechanical and biological characteristics. The physical and mechanical properties of the newly developed membrane are preserved after storage for at least 1 month at - 20 °C.
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Affiliation(s)
- Eduardo Anitua
- Regenerative Medicine Laboratory, Biotechnology Institute (BTI), Vitoria, Spain; Research and Development Department, University Institute for Regenerative Medicine and Oral Implantology-UIRMI (UPV/EHU-Fundación Eduardo Anitua), 01007 Vitoria, Spain.
| | - Francisco Muruzabal
- Regenerative Medicine Laboratory, Biotechnology Institute (BTI), Vitoria, Spain; Research and Development Department, University Institute for Regenerative Medicine and Oral Implantology-UIRMI (UPV/EHU-Fundación Eduardo Anitua), 01007 Vitoria, Spain
| | - María de la Fuente
- Regenerative Medicine Laboratory, Biotechnology Institute (BTI), Vitoria, Spain; Research and Development Department, University Institute for Regenerative Medicine and Oral Implantology-UIRMI (UPV/EHU-Fundación Eduardo Anitua), 01007 Vitoria, Spain
| | - Jesús Merayo-Lloves
- Instituto Oftalmológico Fernández-Vega. Fundación de Investigación Oftalmológica. Universidad de Oviedo, Oviedo, Spain
| | - Mohammad H Alkhraisat
- Regenerative Medicine Laboratory, Biotechnology Institute (BTI), Vitoria, Spain; Research and Development Department, University Institute for Regenerative Medicine and Oral Implantology-UIRMI (UPV/EHU-Fundación Eduardo Anitua), 01007 Vitoria, Spain
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10
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Biomechanics of keratoconus: Two numerical studies. PLoS One 2023; 18:e0278455. [PMID: 36730305 PMCID: PMC9894483 DOI: 10.1371/journal.pone.0278455] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/16/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND The steep cornea in keratoconus can greatly impair eyesight. The etiology of keratoconus remains unclear but early injury that weakens the corneal stromal architecture has been implicated. To explore keratoconus mechanics, we conducted two numerical simulation studies. METHODS A finite-element model describing the five corneal layers and the heterogeneous mechanical behaviors of the ground substance and lamellar collagen-fiber architecture in the anterior and posterior stroma was developed using the Holzapfel-Gasser-Ogden constitutive model. The geometry was from a healthy subject. Its stroma was divided into anterior, middle, and posterior layers to assess the effect of changing regional mechanical parameters on corneal displacement and maximum principal stress under intraocular pressure. Specifically, the effect of softening an inferocentral corneal button, the collagen-based tissues throughout the whole cornea, or specific stromal layers in the button was examined. The effect of simply disorganizing the orthogonally-oriented posterior stromal fibers in the button was also assessed. The healthy cornea was also subjected to eye rubbing-like loading to identify the corneal layer(s) that experienced the most tensional stress. RESULTS Conical deformation and corneal thinning emerged when the corneal button or the mid-posterior stroma of the button underwent gradual softening or when the collagen fibers in the mid-posterior stroma of the button were dispersed. Softening the anterior layers of the button or the whole cornea did not evoke conical deformation. Button softening greatly increased and disrupted the stress on Bowman's membrane while mid-posterior stromal softening increased stress in the anterior layers. Eye rubbing profoundly stressed the deep posterior stroma while other layers were negligibly affected. DISCUSSION These observations suggest that keratoconus could be initiated, at least partly, by mechanical instability/damage in the mid-posterior stroma that then imposes stress on the anterior layers. This may explain why subclinical keratoconus is marked by posterior but not anterior elevation on videokeratoscopy.
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Tran TL, Hamann S, Heegaard S. Aquaporins in Eye. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:203-209. [PMID: 36717496 DOI: 10.1007/978-981-19-7415-1_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The major part of the eye consists of water. Continuous movement of water and ions between the ocular compartments and to the systemic circulation is pivotal for many physiological functions in the eye. The movement of water facilitates removal of the many metabolic products of corneal-, ciliary body-, lens-, and retinal metabolism, while maintaining transparency in the optical compartments. Transport across the corneal epithelium and endothelium maintains the corneal transparency. Also, aqueous humor is continuously secreted by the epithelia of the ciliary body and maintains the intraocular pressure. In the retina, water is transported into the vitreous body and across the retinal pigment epithelium to regulate the extracellular environment and the hydration of the retina. Aquaporins are a major contributor in the water transport throughout the eye.
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Affiliation(s)
- Thuy Linh Tran
- Department of Ophthalmology, Rigshospitalet - Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet - Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Steffen Heegaard
- Department of Ophthalmology, Rigshospitalet - Glostrup, University of Copenhagen, Copenhagen, Denmark
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12
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Rafat M, Jabbarvand M, Sharma N, Xeroudaki M, Tabe S, Omrani R, Thangavelu M, Mukwaya A, Fagerholm P, Lennikov A, Askarizadeh F, Lagali N. Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts. Nat Biotechnol 2023; 41:70-81. [PMID: 35953672 PMCID: PMC9849136 DOI: 10.1038/s41587-022-01408-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/29/2022] [Indexed: 01/25/2023]
Abstract
Visual impairment from corneal stromal disease affects millions worldwide. We describe a cell-free engineered corneal tissue, bioengineered porcine construct, double crosslinked (BPCDX) and a minimally invasive surgical method for its implantation. In a pilot feasibility study in India and Iran (clinicaltrials.gov no. NCT04653922 ), we implanted BPCDX in 20 advanced keratoconus subjects to reshape the native corneal stroma without removing existing tissue or using sutures. During 24 months of follow-up, no adverse event was observed. We document improvements in corneal thickness (mean increase of 209 ± 18 µm in India, 285 ± 99 µm in Iran), maximum keratometry (mean decrease of 13.9 ± 7.9 D in India and 11.2 ± 8.9 D in Iran) and visual acuity (to a mean contact-lens-corrected acuity of 20/26 in India and spectacle-corrected acuity of 20/58 in Iran). Fourteen of 14 initially blind subjects had a final mean best-corrected vision (spectacle or contact lens) of 20/36 and restored tolerance to contact lens wear. This work demonstrates restoration of vision using an approach that is potentially equally effective, safer, simpler and more broadly available than donor cornea transplantation.
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Affiliation(s)
- Mehrdad Rafat
- LinkoCare Life Sciences AB, Linköping, Sweden.
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
| | - Mahmoud Jabbarvand
- Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Namrata Sharma
- R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Maria Xeroudaki
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Shideh Tabe
- LinkoCare Life Sciences AB, Linköping, Sweden
| | - Raha Omrani
- LinkoCare Life Sciences AB, Linköping, Sweden
| | | | - Anthony Mukwaya
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Per Fagerholm
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Anton Lennikov
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Farshad Askarizadeh
- Department of Optometry, Faculty of Rehabilitation Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Neil Lagali
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
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13
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Silva HF, Martins IS, Bogdanov AA, Tuchin VV, Oliveira LM. Characterization of optical clearing mechanisms in muscle during treatment with glycerol and gadobutrol solutions. JOURNAL OF BIOPHOTONICS 2023; 16:e202200205. [PMID: 36101493 DOI: 10.1002/jbio.202200205] [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: 07/01/2022] [Revised: 08/18/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
The recent increasing interest in the application of radiology contrasting agents to create transparency in biological tissues implies that the diffusion properties of those agents need evaluation. The comparison of those properties with the ones obtained for other optical clearing agents allows to perform an optimized agent selection to create optimized transparency in clinical applications. In this study, the evaluation and comparison of the diffusion properties of gadobutrol and glycerol in skeletal muscle was made, showing that although gadobutrol has a higher molar mass than glycerol, its low viscosity allows for a faster diffusion in the muscle. The characterization of the tissue dehydration and refractive index matching mechanisms of optical clearing was made in skeletal muscle, namely by the estimation of the diffusion coefficients for water, glycerol and gadobutrol. The estimated tortuosity values of glycerol (2.2) and of gadobutrol (1.7) showed a longer path-length for glycerol in the muscle.
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Affiliation(s)
- Hugo F Silva
- Centre of Innovation in Engineering and Industrial Technology (CIETI), Polytechnic of Porto, Porto, Portugal
| | - Inês S Martins
- Centre of Innovation in Engineering and Industrial Technology (CIETI), Polytechnic of Porto, Porto, Portugal
| | - Alexei A Bogdanov
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
- Department of Radiology, UMass Chan Medical School, Worcester, Massachusetts, USA
- Department of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russian Federation
| | - Valery V Tuchin
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russian Federation
- Science Medical Center, Saratov State University, Saratov, Russian Federation
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Tomsk, Russian Federation
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control, FRC "Saratov Research Centre of Russian Academy of Sciences,", Saratov, Russian Federation
| | - Luís M Oliveira
- Centre of Innovation in Engineering and Industrial Technology (CIETI), Polytechnic of Porto, Porto, Portugal
- Physics Department, School of Engineering, Polytechnic of Porto, Porto, Portugal
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14
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Jaffey JA, Bullock G, Guo J, Mhlanga-Mutangadura T, O’Brien DP, Coates JR, Morrissey R, Hutchison R, Donnelly KS, Cohn LA, Katz ML, Johnson GS. Novel Homozygous ADAMTS2 Variants and Associated Disease Phenotypes in Dogs with Dermatosparactic Ehlers-Danlos Syndrome. Genes (Basel) 2022; 13:2158. [PMID: 36421833 PMCID: PMC9690363 DOI: 10.3390/genes13112158] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/11/2022] [Accepted: 11/16/2022] [Indexed: 08/22/2023] Open
Abstract
Tissue fragility, skin hyperextensibility and joint hypermobility are defining characteristics of Ehlers-Danlos syndrome (EDS). Human EDS is subclassified into fourteen types including dermatosparactic EDS, characterized by extreme skin fragility and caused by biallelic ADAMTS2 mutations. We report two novel, ADAMTS2 variants in DNA from EDS-affected dogs. Separate whole-genome sequences from a Pit Bull Terrier and an Alapaha Blue Blood Bulldog each contained a rare, homozygous variant (11:2280117delC, CanFam3.1), predicted to produce a frameshift in the transcript from the first coding ADAMTS2 exon (c.10delC) and a severely truncated protein product, p.(Pro4ArgfsTer175). The clinical features of these dogs and 4 others with the same homozygous deletion included multifocal wounds, atrophic scars, joint hypermobility, narrowed palpebral fissures, skin hyperextensibility, and joint-associated swellings. Due to severe skin fragility, the owners of all 6 dogs elected euthanasia before the dogs reached 13 weeks of age. Cross sections of collagen fibrils in post-mortem dermal tissues from 2 of these dogs showed hieroglyphic-like figures similar to those from cases of severe dermatosparaxis in other species. The whole-genome sequence from an adult Catahoula Leopard Dog contained a homozygous ADAMTS2 missense mutation, [11:2491238G>A; p.(Arg966His)]. This dog exhibited multifocal wounds, atrophic scars, and joint hypermobility, but has survived for at least 9 years. This report expands the spectrum of clinical features of the canine dermatosparactic subtype of EDS and illustrates the potential utility of subclassifying canine EDS by the identity of gene harboring the causal variant.
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Affiliation(s)
- Jared A. Jaffey
- Department of Specialty Medicine, College of Veterinary Medicine, Midwestern University, Glendale, AZ 85308, USA
| | - Garrett Bullock
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Juyuan Guo
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Tendai Mhlanga-Mutangadura
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Dennis P. O’Brien
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Joan R. Coates
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | | | - Robert Hutchison
- Animal Clinic Northview, 36400 Center Ridge Rd., North Ridgeville, OH 44039, USA
| | - Kevin S. Donnelly
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Leah A. Cohn
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Martin L. Katz
- Neurodegenerative Diseases Research Laboratory, Department of Ophthalmology, University of Missouri, Columbia, MO 65212, USA
| | - Gary S. Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
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15
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Quinlan RA, Clark JI. Insights into the biochemical and biophysical mechanisms mediating the longevity of the transparent optics of the eye lens. J Biol Chem 2022; 298:102537. [PMID: 36174677 PMCID: PMC9638808 DOI: 10.1016/j.jbc.2022.102537] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/20/2022] [Accepted: 09/22/2022] [Indexed: 11/18/2022] Open
Abstract
In the human eye, a transparent cornea and lens combine to form the "refracton" to focus images on the retina. This requires the refracton to have a high refractive index "n," mediated largely by extracellular collagen fibrils in the corneal stroma and the highly concentrated crystallin proteins in the cytoplasm of the lens fiber cells. Transparency is a result of short-range order in the spatial arrangement of corneal collagen fibrils and lens crystallins, generated in part by post-translational modifications (PTMs). However, while corneal collagen is remodeled continuously and replaced, lens crystallins are very long-lived and are not replaced and so accumulate PTMs over a lifetime. Eventually, a tipping point is reached when protein aggregation results in increased light scatter, inevitably leading to the iconic protein condensation-based disease, age-related cataract (ARC). Cataracts account for 50% of vision impairment worldwide, affecting far more people than other well-known protein aggregation-based diseases. However, because accumulation of crystallin PTMs begins before birth and long before ARC presents, we postulate that the lens protein PTMs contribute to a "cataractogenic load" that not only increases with age but also has protective effects on optical function by stabilizing lens crystallins until a tipping point is reached. In this review, we highlight decades of experimental findings that support the potential for PTMs to be protective during normal development. We hypothesize that ARC is preventable by protecting the biochemical and biophysical properties of lens proteins needed to maintain transparency, refraction, and optical function.
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Affiliation(s)
- Roy A Quinlan
- Department of Biosciences, Durham University, South Road Science Site, Durham, United Kingdom; Department of Biological Structure, University of Washington, Seattle, Washington, USA.
| | - John I Clark
- Department of Biological Structure, University of Washington, Seattle, Washington, USA.
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16
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Zander DB, Jiang J, Reinhard T, Wacker K. Corneal Oedema: Aetiology, Diagnostic Testing, and Treatment. Klin Monbl Augenheilkd 2022; 239:752-759. [DOI: 10.1055/a-1759-3834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractCorneal oedema results from an underlying pathology, which can be diverse in origin, and may be mechanical, dystrophic, or inflammatory, and affect any layer of the cornea. Diagnostic tools
such as Scheimpflug imaging and anterior segment optical coherence tomography have standardised quantification of corneal oedema and have become important aids in clinical practice. Timely
diagnosis and treatment are key to preventing irreversible damage to the corneal ultrastructure, such as anterior corneal fibrosis or endothelial cell damage. The oedema usually resolves
quickly when the underlying cause has been addressed. Symptomatic treatment using hyperosmolar agents has failed to show any benefits in oedema resolution or improvement in visual acuity
compared to placebo. In contrast, rho-associated protein kinase (ROCK) inhibitors offer a promising option for medical treatment in cases of endothelial dysfunction, but their safety and
efficacy must be further validated in large scale clinical trials. Until then, endothelial or penetrating keratoplasties remain the mainstay treatment where structural changes to the cornea
have occurred.
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Affiliation(s)
| | - Jana Jiang
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
| | - Thomas Reinhard
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
| | - Katrin Wacker
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
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17
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Muntz I, Fenu M, van Osch GJVM, Koenderink G. The role of cell-matrix interactions in connective tissue mechanics. Phys Biol 2021; 19. [PMID: 34902848 DOI: 10.1088/1478-3975/ac42b8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/13/2021] [Indexed: 11/12/2022]
Abstract
Living tissue is able to withstand large stresses in everyday life, yet it also actively adapts to dynamic loads. This remarkable mechanical behaviour emerges from the interplay between living cells and their non-living extracellular environment. Here we review recent insights into the biophysical mechanisms involved in the reciprocal interplay between cells and the extracellular matrix and how this interplay determines tissue mechanics, with a focus on connective tissues. We first describe the roles of the main macromolecular components of the extracellular matrix in regards to tissue mechanics. We then proceed to highlight the main routes via which cells sense and respond to their biochemical and mechanical extracellular environment. Next we introduce the three main routes via which cells can modify their extracellular environment: exertion of contractile forces, secretion and deposition of matrix components, and matrix degradation. Finally we discuss how recent insights in the mechanobiology of cell-matrix interactions are furthering our understanding of the pathophysiology of connective tissue diseases and cancer, and facilitating the design of novel strategies for tissue engineering.
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Affiliation(s)
- Iain Muntz
- Bionanoscience, TU Delft, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Maasweg 9, Delft, Zuid-Holland, 2629 HC, NETHERLANDS
| | - Michele Fenu
- Otorhinolaryngology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Zuid-Holland, 3000 CA, NETHERLANDS
| | - Gerjo J V M van Osch
- Orthopaedics; Otorhinolaryngology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Zuid-Holland, 3000 CA, NETHERLANDS
| | - Gijsje Koenderink
- Bionanoscience, TU Delft, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Maasweg 9, Delft, Zuid-Holland, 2629 HZ, NETHERLANDS
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18
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Wahab C, Fakhoury O, Serhan H, Ayash J, Jabbour F, Dirani A, Kallassy M, Waked N. Biomolecular evaluation of cryopreserved amniotic membranes for ophthalmological use by ELISA and RT-PCR at one and eighteen months. J Fr Ophtalmol 2021; 44:1529-1535. [PMID: 34728097 DOI: 10.1016/j.jfo.2021.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/04/2021] [Accepted: 05/24/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE To study the presence of certain proteins - EGF (epidermal growth factor), KGF (keratinocyte growth factor), IL-10 (interleukin 10), HGF (hepatocyte growth factor), Alpha2-macroglobulin and IL-1RA (interleukin 1 receptor antagonist) in cryopreserved amniotic membranes at 1 and 18 months and, as a secondary objective, to detect mRNA corresponding to KGF, IL-1Ra, Alpha2-macroglobulin, Fas Ligand, TGF beta (transforming growth factor beta) and Lumican by RT-PCR in membranes preserved at 1 and 18 months. MATERIAL AND METHODS Four samples of amniotic membrane were divided into 2 groups: the first group (N=2) cryopreserved for 1 month and the second group (N=2) cryopreserved for 18 months, in order to be studied by RT-PCR and ELISA. RESULTS RT-PCR detected KGF, IL-1Ra, Alpha2-macroglobulin, Fas Ligand, and Lumican. Of these, FAS Ligand mRNA was found in samples preserved for 1and 18 months. KGF, Lumican, and alpha2-microglobulin mRNA were found only at 1 month, and IL-1Ra mRNA was absent in both sample groups. RT-PCR for TGF-beta was inconclusive. ELISA was performed for detection and quantification of 6 proteins (EGF, KGF, IL-10, HGF, Alpha2-macroglobulin and IL-1Ra) in both amniotic membrane groups. All 6 proteins were found in all samples, with a lower concentration at 18 months compared to 1 month of preservation. CONCLUSION This study shows that membranes cryopreserved in 50% glycerol for 18 months do retain the proteins necessary for regeneration of the corneal surface, giving these membranes their biochemical properties.
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Affiliation(s)
- C Wahab
- Département d'ophtalmologie du centre médical universitaire de l'hôpital Saint-George en association avec l'université de Balamand, Beyrouth, Liban
| | - O Fakhoury
- Département d'ophtalmologie du centre médical universitaire de l'hôpital Saint-George en association avec l'université de Balamand, Beyrouth, Liban.
| | - H Serhan
- Département d'ophtalmologie du centre médical universitaire de l'hôpital Saint-George en association avec l'université de Balamand, Beyrouth, Liban
| | - J Ayash
- Département d'ophtalmologie du centre médical universitaire de l'hôpital Saint-George en association avec l'université de Balamand, Beyrouth, Liban
| | - F Jabbour
- Département d'ophtalmologie du centre médical universitaire de l'hôpital Saint-George en association avec l'université de Balamand, Beyrouth, Liban
| | - A Dirani
- Département d'ophtalmologie CHU de Québec, Québec, Canada
| | - M Kallassy
- Département des sciences de la terre et de la vie, université Saint-Joseph, Beyrouth, Liban
| | - N Waked
- Département d'ophtalmologie de l'Hôtel Dieu de France, Beyrouth, Liban
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19
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Epidermal Growth Factor Receptor Expression in the Corneal Epithelium. Cells 2021; 10:cells10092409. [PMID: 34572058 PMCID: PMC8470622 DOI: 10.3390/cells10092409] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/31/2021] [Accepted: 09/07/2021] [Indexed: 01/12/2023] Open
Abstract
A properly functioning cornea is critical to clear vision and healthy eyes. As the most anterior portion of the eye, it plays an essential role in refracting light onto the retina and as an anatomical barrier to the environment. Proper vision requires that all layers be properly formed and fully intact. In this article, we discuss the role of the epidermal growth factor receptor (EGFR) in maintaining and restoring the outermost layer of the cornea, the epithelium. It has been known for some time that the addition of epidermal growth factor (EGF) promotes the restoration of the corneal epithelium and patients using EGFR inhibitors as anti-cancer therapies are at increased risk of corneal erosions. However, the use of EGF in the clinic has been limited by downregulation of the receptor. More recent advances in EGFR signaling and trafficking in corneal epithelial cells have provided new insights in how to overcome receptor desensitization. We examine new strategies for overcoming the limitations of high ligand and receptor expression that alter trafficking of the ligand:receptor complex to sustain receptor signaling.
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20
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Wong HL, Hung LT, Kwok SS, Bu Y, Lin Y, Shum HC, Wang H, Lo ACY, Yam GHF, Jhanji V, Shih KC, Chan YK. The anti-scarring role of Lycium barbarum polysaccharide on cornea epithelial-stromal injury. Exp Eye Res 2021; 211:108747. [PMID: 34450184 DOI: 10.1016/j.exer.2021.108747] [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] [Received: 03/22/2021] [Revised: 08/07/2021] [Accepted: 08/22/2021] [Indexed: 12/16/2022]
Abstract
PURPOSE Cornea epithelial-stromal scarring is related to the differentiation of fibroblasts into opaque myofibroblasts. Our study aims to assess the effectiveness of Lycium barbarum polysaccharide (LBP) solution as a pre-treatment in minimizing corneal scarring. METHODS Human corneal fibroblasts were cultured in a three-dimensional collagen type I-based hydrogel in an eye-on-a-chip model. Fibroblasts were pre-treated with 2 mg/mL LBP for 24 h, followed by another 24-h incubation with 10 ng/mL transforming growth factor-beta 1 (TGF-β1) to induce relevant physiological events after stromal injury. Intracellular pro-fibrotic proteins, extracellular matrix proteins, and pro-inflammatory cytokines that involved in fibrosis, were assessed using immunocytochemistry and enzyme-linked immunosorbent assays. RESULTS Compared to the positive control TGF-β1 group, LBP pre-treated cells had a significantly lower expression of alpha-smooth muscle actin, marker of myofibroblasts, vimentin (p < 0.05), and also extracellular matrix proteins both collagen type II and type III (p < 0.05) that can be found in scar tissues. Moreover, LBP pre-treated cells had a significantly lower secretion of pro-inflammatory cytokines interleukin-6 and interleukin-8 (p < 0.05). The cell-laden hydrogel contraction and stiffness showed no significant difference between LBP pre-treatment and control groups. Fibroblasts pretreated with LBP as well had reduced angiogenic factors expression and suppression of undesired proliferation (p < 0.05). CONCLUSION Our results showed that LBP reduced both pro-fibrotic proteins and pro-inflammatory cytokines on corneal injury in vitro. We suggest that LBP, as a natural Traditional Chinese Medicine, may potentially be a novel topical pre-treatment option prior to corneal refractive surgeries with an improved prognosis.
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Affiliation(s)
- Ho Lam Wong
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Lap Tak Hung
- Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Sum Sum Kwok
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Yashan Bu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Yuan Lin
- Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Ho Cheung Shum
- Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Hua Wang
- Eye Center of Xiangya Hospital, Central South University, China; Hunan Key Laboratory of Ophthalmology, China
| | - Amy Cheuk Yin Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Gary Hin Fai Yam
- Department of Ophthalmology, University of Pittsburgh Medical Centre, USA
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh Medical Centre, USA
| | - Kendrick Co Shih
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
| | - Yau Kei Chan
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
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21
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Zhou W, Reinstein DZ, Archer TJ, Chen X, Utheim TP, Feng Y, Stojanovic A. Intraoperative Swept-Source OCT-Based Corneal Topography for Measurement and Analysis of Stromal Surface After Epithelial Removal. J Refract Surg 2021; 37:484-492. [PMID: 34236903 DOI: 10.3928/1081597x-20210405-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess intraoperative stromal topography measurements using swept-source optical coherence tomography (OCT)-based topography/tomography after epithelial removal and to analyze the epithelial contribution to the corneal topography and optics. METHODS This was a prospective series of 22 eyes of 19 patients referred to receive phototherapeutic keratotomy (PTK) for treatment of recurrent corneal erosion and a control group of 22 virgin eyes. Swept-source OCT corneal topography/tomography was obtained immediately before and immediately after mechanical deepithelialization before PTK. Epithelial thickness maps were obtained before the surgery using spectral-domain OCT in the control group and as a reference in the group with anterior basement membrane dystrophy. Topographic and optical characteristics, including the curvature, astigmatism, asphericity, and higher order aberrations of the cornea before and after deepithelialization were compared, and their differences correlated with the measurements derived from the epithelial thickness maps. RESULTS Stromal topography measurements after deepithelialization were easily obtained and showed excellent repeatability. Assessment of corneal edema induced by deepithelialization revealed that it did not significantly affect the measured parameters. The stromal surface was steeper by 1.28 diopters, had higher with-the-rule astigmatism by 0.41 diopters, was more prolate, and had more higher order aberrations compared to the intact epithelialized corneal surface. These differences correlated well with the parameters derived from epithelial thickness maps. CONCLUSIONS Measurement of stromal topography using swept-source OCT immediately after mechanical deepithelialization may be a viable method in therapeutic refractive surgery, where stromal topography-guided ablation is needed. A significant epithelial contribution to anterior corneal topography and optics was confirmed. [J Refract Surg. 2021;37(7):484-492.].
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22
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Neroev VV, Iomdina EN, Khandzhyan AT, Khodzhabekyan NV, Sengaeva MD, Ivanova AV, Seliverstov SV, Teplyakova KO, Goltsman GN. [Experimental study of the effect of corneal hydration and its biomechanical properties on the results of photorefractive keratectomy]. Vestn Oftalmol 2021; 137:68-75. [PMID: 34156780 DOI: 10.17116/oftalma202113703168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Water content in the cornea may affect the outcome of its excimer laser ablation, especially in presbyopic patients with myopic refraction. This hypothesis can be tested by scanning the cornea in the terahertz (THz) range to determine its hydration level. PURPOSE To study the effect of hydration of the cornea determined by non-contact THz scanning and its biomechanical parameters on the results of photorefractive keratectomy (PRK) in an experiment. MATERIAL AND METHODS PRK was performed using the Nidek EC-5000 QUEST excimer laser on 8 rabbit eyes. Corneal hydration was evaluated by determining the reflection coefficient (RC) in the THz electromagnetic radiation range before PRK, after 3-5 days, and after 1, 2, 3, and 4 months. Clinical examination included autorefractometry, assessment of corneal thickness and other anatomical and optical parameters of the anterior eye segment (Galilei G6, Ziemer Ophthalmic Systems AG 6.0.2, Switzerland), measurement of corneal hysteresis (CH) and corneal resistance factor (CRF) using the Ocular Response Analyzer (ORA; Reichert, USA), as well as tear production (Schirmer test). RESULTS The initial water content in the cornea has a significant effect on the thickness of the removed layer, i.e. on the PRK effect, with correlation coefficient of Rs= -0.976 (p<0.01). The correlation between CH and the ablation depth is less pronounced (Rs=0.643), and CRF had no correlation with it (Rs= -0.089). Biomechanical indicators of the cornea depend on its hydration: changes in CH and CRF after excimer laser ablation qualitatively coincide with changes in RC, the correlation coefficient between RC and the initial value of CH is R= -0.619 (moderate negative correlation). CONCLUSION THz scanning is an effective non-contact technology for monitoring corneal hydration level. The mismatch of the hypoeffect of keratorefractive excimer laser intervention planned for patients with presbyopia with the actual outcome can be caused by individual decrease in the initial water content in the cornea.
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Affiliation(s)
- V V Neroev
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - E N Iomdina
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - A T Khandzhyan
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - N V Khodzhabekyan
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - M D Sengaeva
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - A V Ivanova
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | | | | | - G N Goltsman
- Moscow Pedagogical State University, Moscow, Russia
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23
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Iomdina EN, Seliverstov SV, Teplyakova KO, Jani EV, Pozdniakova VV, Polyakova ON, Goltsman GN. Terahertz scanning of the rabbit cornea with experimental UVB-induced damage: in vivo assessment of hydration and its verification. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200394SSRR. [PMID: 33834684 PMCID: PMC8027227 DOI: 10.1117/1.jbo.26.4.043010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/15/2021] [Indexed: 05/28/2023]
Abstract
SIGNIFICANCE Water content plays a vital role in the normally functioning visual system; even a minor disruption in the water balance may be harmful. Today, no direct method exists for corneal hydration assessment, while it could be instrumental in early diagnosis and control of a variety of eye diseases. The use of terahertz (THz) radiation, which is highly sensitive to water content, appears to be very promising. AIM To find out how THz scanning parameters of corneal tissue measured by an experimental setup, specially developed for in vivo contactless estimations of corneal reflectivity coefficient (RC), are related to pathological changes in the cornea caused by B-band ultraviolet (UVB) exposure. APPROACH The setup was tested on rabbit eyes in vivo. Prior to the course of UVB irradiation and 1, 5, and 30 days after it, a series of examinations of the corneal state was made. At the same time points, corneal hydration was assessed by measuring RC. RESULTS The obtained data confirmed the negative impact of UVB irradiation course on the intensity of tear production and on the corneal thickness and optical parameters. A significant (1.8 times) increase in RC on the 5th day after the irradiation course, followed by a slight decrease on the 30th day after it was revealed. The RC increase measured 5 days after the UVB irradiation course generally corresponded to the increase (by a factor of 1.3) of tear production. RC increase occurred with the corneal edema, which was manifested by corneal thickening (by 18.2% in the middle area and 17.6% in corneal periphery) and an increased volume of corneal tissue (by 17.6%). CONCLUSIONS Our results demonstrate that the proposed approach can be used for in vivo contactless estimation of the reflectivity of rabbit cornea in the THz range and, thereby, of cornea hydration.
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Affiliation(s)
- Elena N. Iomdina
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | | | | | - Elena V. Jani
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | | | - Olga N. Polyakova
- Moscow Pedagogical State University, Department of Physics, Moscow, Russia
| | - Gregory N. Goltsman
- Moscow Pedagogical State University, Department of Physics, Moscow, Russia
- National Research University Higher School of Economics, Moscow Institute of Electronics and Mathematics, Moscow, Russia
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Parker J, Dockery P, Preda-Naumescu A, Jager M, van Dijk K, Dapena I, Melles G. Descemet Membrane Endothelial Keratoplasty and Bowman Layer Transplantation: An Anatomic Review and Historical Survey. Ophthalmic Res 2021; 64:532-553. [PMID: 33761502 DOI: 10.1159/000516093] [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: 12/10/2020] [Accepted: 03/23/2021] [Indexed: 11/19/2022]
Abstract
For nearly a century, the definitive treatment of many corneal dystrophies and ectactic disorders was limited to penetrating keratoplasty, but over the past 2 decades, a surge of surgical innovation has propelled the treatment of many corneal diseases to more targeted approaches with significantly better visual outcomes. Anterior stromal diseases were first changed through endothelial-sparing techniques, such as deep anterior lamellar keratoplasty, but have more recently transitioned to stromal-sparing approaches. Ultraviolet corneal crosslinking strengthens the cornea and halts progression of keratoconus in >90% of cases. Intracorneal ring segment and corneal allogenic ring segment implantation offer methods to flatten ectatic corneas. However, Bowman layer transplantation - inlay and more recently onlay techniques - has shown promise for treating advanced keratoconus and preventing keratoplasty. The advent of endothelial keratoplasty radically changed the treatment of corneal endothelial dysfunction, and Descemet membrane endothelial keratoplasty specifically offers an average postoperative visual acuity of 20/25 (0.8) with only 8.8% of grafts requiring retransplantation in the first 5 years. Here, we review the rapid innovations for surgical treatment of corneal diseases, spanning from endothelial keratoplasty and endothelial regeneration to anterior lamellar keratoplasty and stromal augmentation, highlighting key steps which may be moving us closer to a "postkeratoplasty" world.
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Affiliation(s)
- Jack Parker
- Parker Cornea, Birmingham, Alabama, USA.,Netherlands Institute for Innovative Ocular Surgery- USA (NIIOS-USA), San Diego, California, USA
| | - Philip Dockery
- Parker Cornea, Birmingham, Alabama, USA.,Wills Eye Hospital, Philadelphia, Pennsylvania, USA
| | - Ana Preda-Naumescu
- University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Martine Jager
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Korine van Dijk
- Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, The Netherlands.,Melles Cornea Clinic Rotterdam, Rotterdam, The Netherlands
| | - Isabel Dapena
- Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, The Netherlands.,Melles Cornea Clinic Rotterdam, Rotterdam, The Netherlands
| | - Gerrit Melles
- Parker Cornea, Birmingham, Alabama, USA.,Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, The Netherlands.,Melles Cornea Clinic Rotterdam, Rotterdam, The Netherlands
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Sharifi S, Sharifi H, Guild C, Islam MM, Tran KD, Patzer C, Dohlman CH, Paschalis EI, Gonzalez-Andrades M, Chodosh J. Toward electron-beam sterilization of a pre-assembled Boston keratoprosthesis. Ocul Surf 2021; 20:176-184. [PMID: 33667673 DOI: 10.1016/j.jtos.2021.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/07/2021] [Accepted: 02/18/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE To evaluate the effects of electron-beam (E-beam) irradiation on the human cornea and the potential for E-beam sterilization of Boston keratoprosthesis (BK) devices when pre-assembled with a donor cornea prior to sterilization. METHODS Human donor corneas and corneas pre-assembled in BK devices were immersed in recombinant human serum albumin (rHSA) media and E-beam irradiated at 25 kGy. Mechanical (tensile strength and modulus, and compression modulus), chemical, optical, structural, and degradation properties of the corneal tissue after irradiation and after 6 months of preservation were evaluated. RESULTS The mechanical evaluation showed that E-beam irradiation enhanced the tensile and compression moduli of human donor corneas, with no impact on their tensile strength. By chemical and mechanical analysis, E-beam irradiation caused a minor degree of crosslinking between collagen fibrils. No ultrastructural changes due to E-beam irradiation were observed. E-beam irradiation slightly increased the stability of the cornea against collagenase-induced degradation and had no impact on glucose diffusion. The optical evaluation showed transparency of the cornea was maintained. E-beam irradiated corneal tissues and BK-cornea pre-assembled devices were stable for 6 months after room-temperature preservation. CONCLUSIONS E-beam irradiation generated no detrimental effects on the corneal tissues or BK-cornea pre-assembled devices and improved native properties of the corneal tissue, enabling prolonged preservation at room temperature. The pre-assembly of BK in a donor cornea, followed by E-beam irradiation, offers the potential for an off-the-shelf, ready to implant keratoprosthesis device.
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Affiliation(s)
- Sina Sharifi
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Hannah Sharifi
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | | | - Mohammad Mirazul Islam
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Khoa D Tran
- Vision Research Laboratory, Lions VisionGift, Portland, OR, USA
| | - Corrina Patzer
- Vision Research Laboratory, Lions VisionGift, Portland, OR, USA
| | - Claes H Dohlman
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Eleftherios I Paschalis
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Miguel Gonzalez-Andrades
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Department of Ophthalmology, Reina Sofia University Hospital and University of Cordoba, Cordoba, Spain.
| | - James Chodosh
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
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26
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White TL, Deshpande N, Kumar V, Gauthier AG, Jurkunas UV. Cell cycle re-entry and arrest in G2/M phase induces senescence and fibrosis in Fuchs Endothelial Corneal Dystrophy. Free Radic Biol Med 2021; 164:34-43. [PMID: 33418109 PMCID: PMC7897316 DOI: 10.1016/j.freeradbiomed.2020.12.445] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/27/2020] [Accepted: 12/28/2020] [Indexed: 12/13/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is an age-related disease whereby progressive loss of corneal endothelial cells (CEnCs) leads to loss of vision. There is currently a lack of therapeutic interventions as the etiology of the disease is complex, with both genetic and environmental factors. In this study, we have provided further insights into the pathogenesis of the disease, showing a causal relationship between senescence and endothelial-mesenchymal transition (EMT) using in vitro and in vivo models. Ultraviolet A (UVA) light induced EMT and senescence in CEnCs. Senescent cells were arrested in G2/M phase of the cell cycle and responsible for the resulting profibrotic phenotype. Inhibiting ATR signaling and subsequently preventing G2/M arrest attenuated EMT. In vivo, UVA irradiation induced cell cycle re-entry in post mitotic CEnCs, resulting in senescence and fibrosis at 1- and 2-weeks post-UVA. Selectively eliminating senescent cells using the senolytic cocktail of dasatinib and quercetin attenuated UVA-induced fibrosis, highlighting the potential for a new therapeutic intervention for FECD.
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Affiliation(s)
- Tomas L White
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Neha Deshpande
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Varun Kumar
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Alex G Gauthier
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Ula V Jurkunas
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA.
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27
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Guérin LP, Le-Bel G, Desjardins P, Couture C, Gillard E, Boisselier É, Bazin R, Germain L, Guérin SL. The Human Tissue-Engineered Cornea (hTEC): Recent Progress. Int J Mol Sci 2021; 22:ijms22031291. [PMID: 33525484 PMCID: PMC7865732 DOI: 10.3390/ijms22031291] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
Each day, about 2000 U.S. workers have a job-related eye injury requiring medical treatment. Corneal diseases are the fifth cause of blindness worldwide. Most of these diseases can be cured using one form or another of corneal transplantation, which is the most successful transplantation in humans. In 2012, it was estimated that 12.7 million people were waiting for a corneal transplantation worldwide. Unfortunately, only 1 in 70 patients received a corneal graft that same year. In order to provide alternatives to the shortage of graftable corneas, considerable progress has been achieved in the development of living corneal substitutes produced by tissue engineering and designed to mimic their in vivo counterpart in terms of cell phenotype and tissue architecture. Most of these substitutes use synthetic biomaterials combined with immortalized cells, which makes them dissimilar from the native cornea. However, studies have emerged that describe the production of tridimensional (3D) tissue-engineered corneas using untransformed human corneal epithelial cells grown on a totally natural stroma synthesized by living corneal fibroblasts, that also show appropriate histology and expression of both extracellular matrix (ECM) components and integrins. This review highlights contributions from laboratories working on the production of human tissue-engineered corneas (hTECs) as future substitutes for grafting purposes. It overviews alternative models to the grafting of cadaveric corneas where cell organization is provided by the substrate, and then focuses on their 3D counterparts that are closer to the native human corneal architecture because of their tissue development and cell arrangement properties. These completely biological hTECs are therefore very promising as models that may help understand many aspects of the molecular and cellular mechanistic response of the cornea toward different types of diseases or wounds, as well as assist in the development of novel drugs that might be promising for therapeutic purposes.
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Affiliation(s)
- Louis-Philippe Guérin
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Gaëtan Le-Bel
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Pascale Desjardins
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Camille Couture
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Elodie Gillard
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Élodie Boisselier
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Richard Bazin
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Lucie Germain
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Sylvain L. Guérin
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Correspondence: ; Tel.: +1-418-682-7565
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Regenerative capacity of the corneal transition zone for endothelial cell therapy. Stem Cell Res Ther 2020; 11:523. [PMID: 33276809 PMCID: PMC7716425 DOI: 10.1186/s13287-020-02046-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022] Open
Abstract
The corneal endothelium located on the posterior corneal surface is responsible for regulating stromal hydration. This is contributed by a monolayer of corneal endothelial cells (CECs), which are metabolically active in a continuous fluid-coupled efflux of ions from the corneal stroma into the aqueous humor, preventing stromal over-hydration and preserving the orderly arrangement of stromal collagen fibrils, which is essential for corneal transparency. Mature CECs do not have regenerative capacity and cell loss due to aging and diseases results in irreversible stromal edema and a loss of corneal clarity. The current gold standard of treatment for this worldwide blindness caused by corneal endothelial failure is the corneal transplantation using cadaveric donor corneas. The top indication is Fuchs corneal endothelial dystrophy/degeneration, which represents 39% of all corneal transplants performed. However, the global shortage of transplantable donor corneas has restricted the treatment outcomes, hence instigating a need to research for alternative therapies. One such avenue is the CEC regeneration from endothelial progenitors, which have been identified in the peripheral endothelium and the adjacent transition zone. This review examines the evidence supporting the existence of endothelial progenitors in the posterior limbus and summarizes the existing knowledge on the microanatomy of the transitional zone. We give an overview of the isolation and ex vivo propagation of human endothelial progenitors in the transition zone, and their growth and differentiation capacity to the corneal endothelium. Transplanting these bioengineered constructs into in vivo models of corneal endothelial degeneration will prove the efficacy and viability, and the long-term maintenance of functional endothelium. This will develop a novel regenerative therapy for the management of corneal endothelial diseases.
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29
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Espana EM, Birk DE. Composition, structure and function of the corneal stroma. Exp Eye Res 2020; 198:108137. [PMID: 32663498 PMCID: PMC7508887 DOI: 10.1016/j.exer.2020.108137] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
No other tissue in the body depends more on the composition and organization of the extracellular matrix (ECM) for normal structure and function than the corneal stroma. The precise arrangement and orientation of collagen fibrils, lamellae and keratocytes that occurs during development and is needed in adults to maintain stromal function is dependent on the regulated interaction of multiple ECM components that contribute to attain the unique properties of the cornea: transparency, shape, mechanical strength, and avascularity. This review summarizes the contribution of different ECM components, their structure, regulation and function in modulating the properties of the corneal stroma. Fibril forming collagens (I, III, V), fibril associated collagens with interrupted triple helices (XII and XIV), network forming collagens (IV, VI and VIII) as well as small leucine-rich proteoglycans (SLRP) expressed in the stroma: decorin, biglycan, lumican, keratocan, and fibromodulin are some of the ECM components reviewed in this manuscript. There are spatial and temporal differences in the expression of these ECM components, as well as interactions among them that contribute to stromal function. Unique regions within the stroma like Bowman's layer and Descemet's layer are discussed. To define the complexity of corneal stroma composition and structure as well as the relationship to function is a daunting task. Our knowledge is expanding, and we expect that this review provides a comprehensive overview of current knowledge, definition of gaps and suggests future research directions.
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Affiliation(s)
- Edgar M Espana
- Department of Molecular Pharmacology and Physiology, USA; Cornea, External Disease and Refractive Surgery, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, FL, USA
| | - David E Birk
- Department of Molecular Pharmacology and Physiology, USA.
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30
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Consejo A, Alonso-Caneiro D, Wojtkowski M, Vincent SJ. Corneal tissue properties following scleral lens wear using Scheimpflug imaging. Ophthalmic Physiol Opt 2020; 40:595-606. [PMID: 32705705 PMCID: PMC7540351 DOI: 10.1111/opo.12710] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 05/26/2020] [Indexed: 12/11/2022]
Abstract
Purpose To investigate the effect of short‐term scleral lens wear on the corneal stroma at a macroscopic (thickness) and microscopic (within tissue) level, including regional variations. Methods Fourteen young, healthy participants wore a rotationally symmetric, 16.5 mm diameter, scleral lens for 8 h. Scheimpflug images were captured before, and immediately after, lens wear, and also on a second day (without lens wear) to quantify natural corneal diurnal variations. After corneal segmentation, pixel intensities of the stromal tissue were statistically modelled using a Weibull probability density function from which parameters α and β were derived. Results Both α and β parameters increased significantly following scleral lens wear (by 5.7 ± 10% and 6.5 ± 6.5%, respectively, both p < 0.01). Corneal thickness also increased slightly following lens wear (mean increase 0.49 ± 1.77%, p = 0.01); however, the change in α and β parameters did not correlate with the magnitude of corneal swelling. On the control day, small but significant corneal thinning was observed (−0.82 ± 1.1%, p = 0.03), while α and β parameters remained stable. Both microparameters varied significantly across the cornea, with α decreasing (−15.4 ± 0.7%) and β increasing towards the periphery (+4.4 ± 2.6%) (both p < 0.001). Conclusion Corneal microparameters α and β varied regionally across the cornea and displayed a statistically significant increase following short‐term scleral lens wear, but remained stable between morning and evening measurements taken during a control day without lens wear. These corneal microparameters may be a useful metric to quantify subclinical corneal changes associated with low level hypoxia.
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Affiliation(s)
- Alejandra Consejo
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - David Alonso-Caneiro
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Maciej Wojtkowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Stephen J Vincent
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
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31
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McKay TB, Ford A, Wang S, Cairns DM, Parker RN, Deardorff PM, Ghezzi CE, Kaplan DL. Assembly and Application of a Three-Dimensional Human Corneal Tissue Model. ACTA ACUST UNITED AC 2020; 81:e84. [PMID: 31529796 DOI: 10.1002/cptx.84] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cornea provides a functional barrier separating the outside environment from the intraocular environment, thereby protecting posterior segments of the eye from infection and damage. Pathological changes that compromise the structure or integrity of the cornea may occur as a result of injury or disease and can lead to debilitating effects on visual acuity. Over 10 million people worldwide are visually impaired or blind due to corneal opacity. Thus, physiologically relevant in vitro approaches to predict corneal toxicity of chemicals or effective treatments for disease prior to ocular exposure, as well as to study the corneal effects of systemic, chronic conditions, such as diabetes, are needed to reduce use of animal testing and accelerate therapeutic development. We have previously bioengineered an innervated corneal tissue model using silk protein scaffolds to recapitulate the structural and mechanical elements of the anterior cornea and to model the functional aspects of corneal sensation with the inclusion of epithelial, stromal, and neural components. The purpose of this unit is to provide a step-by-step guide for preparation, assembly, and application of this three-dimensional corneal tissue system to enable the study of corneal tissue biology. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Tina B McKay
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Andrew Ford
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Siran Wang
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Rachael N Parker
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Phillip M Deardorff
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
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Wong HL, Poon SHL, Bu Y, Lo ACY, Jhanji V, Chan YK, Shih KC. A Systematic Review on Cornea Epithelial-Stromal Homeostasis. Ophthalmic Res 2020; 64:178-191. [PMID: 32474566 DOI: 10.1159/000509030] [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: 04/29/2020] [Accepted: 05/29/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION This review aims to summarise the role of different cells, genes, proteins and lipid in regulating cornea epithelial-stromal homeostasis. METHODS We performed an Entrez PubMed literature search using keywords "human," "cornea," "epithelial," "stromal," "homeostasis," "fibrosis response," and "pathogenesis" on 24th of September 2019, resulting in 35 papers, of which 18 were chosen after filtering for "English language" and "published within 10 years" as well as curation for relevance by the authors. RESULTS The 18 selected papers showed that corneal epithelial cells, fibroblasts and telocytes, together with genes such as Klf4, Pax6 and Id found in the cells, play important roles in achieving homeostasis to maintain corneal integrity and transparency. Proteins classified as pro-fibrotic ligands and anti-fibrotic ligands are responsible for regulating cornea stromal fibrosis and extracellular matrix deposition, thus regulators of scar formation during wound healing. Anti-inflammatory ligands and wound repairing ligands are critical in eliciting protective inflammation and promoting epithelial healing, respectively. Protein receptors located on cellular membrane play a role in maintaining intercellular connections as well as corneal hydration. DISCUSSION/CONCLUSION These studies prompt development of novel therapeutic strategies such as tear drops or ointments that target certain proteins to maintain corneal homeostasis. However, more in vitro and in vivo studies are required to prove the effectiveness of exogenous administration of molecules in improving healing outcome. Hence, future investigations of the molecular pathways highlighted in this review will reveal novel therapeutic tools such as gene or cell therapy to treat corneal diseases.
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Affiliation(s)
- Ho Lam Wong
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong, China
| | - Stephanie Hiu Ling Poon
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong, China
| | - Yashan Bu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong, China
| | - Amy Cheuk Yin Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong, China
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh Medical Centre, Pittsburgh, Pennsylvania, USA
| | - Yau Kei Chan
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong, China
| | - Kendrick Co Shih
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong, China,
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Berkowski WM, Gibson DJ, Craft SL, Whitley RD, Schultz GS, Plummer CE. Development and assessment of a novel ex vivo corneal culture technique involving an agarose-based dome scaffold for use as a model of in vivo corneal wound healing in dogs and rabbits. Am J Vet Res 2020; 81:47-57. [PMID: 31887084 DOI: 10.2460/ajvr.81.1.47] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To develop and assess a novel ex vivo corneal culture technique involving an agarose-based dome scaffold (ABDS) for use as a model of in vivo corneal wound healing in dogs and rabbits. SAMPLE Corneas from clinically normal dogs (paired corneas from 8 dogs and 8 single corneas) and rabbits (21 single corneas). PROCEDURES 8 single dog corneas (DCs), 1 DC from each pair, and 10 rabbit corneas (RCs) were wounded with an excimer laser; 1 DC from each pair and 11 RCs remained unwounded. Corneas were cultured for 21 days on ABDSs (8 pairs of DCs and all RCs) or on flat-topped scaffolds (8 single DCs). The surface area of corneal fluorescein retention was measured every 6 (DCs) or 12 (RCs) hours until full corneal epithelialization was detected. Changes in corneal clarity were evaluated at 0, 7, 14, and 21 days. RESULTS Median time to full epithelialization for wounded dog and rabbit corneas was 48 and 60 hours, respectively; among wounded DCs, time to full epithelization did not differ by scaffold type. After 21 days of culture on ABDSs, all DCs and RCs that epithelialized developed a circular, diffuse, cloud-like pattern of optical haze, whereas DCs cultured on flat-topped scaffolds developed a focal, crater-like region of optical haze. All corneas on the ABDSs maintained convex curvature throughout the study. CONCLUSIONS AND CLINICAL RELEVANCE Wounded ex vivo DCs and RCs cultured on ABDSs reliably epithelialized, formed optical haze (consistent with in vivo wound healing), and maintained convex curvature. This culture technique may be adaptable to other species.
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Christaras D, Rozema JJ, Ginis H. Ocular axial length and straylight. Ophthalmic Physiol Opt 2020; 40:316-322. [DOI: 10.1111/opo.12681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/05/2020] [Accepted: 02/06/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Dimitrios Christaras
- Department of Research Athens Eye Hospital Athens Greece
- UCL Institute of Ophthalmology University College London London England
| | - Jos J Rozema
- Department of Ophthalmology Antwerp University Hospital Faculty of Medicine University of Antwerp Edegem Belgium
- Department of Medicine and Health Sciences University of Antwerp Antwerp Belgium
| | - Harilaos Ginis
- Department of Research Athens Eye Hospital Athens Greece
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Ramm L, Spoerl E, Pillunat LE, Terai N. Is the Corneal Thickness Profile Altered in Diabetes Mellitus? Curr Eye Res 2020; 45:1228-1234. [PMID: 32180465 DOI: 10.1080/02713683.2020.1741009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Purpose: To investigate the influence of chronic hyperglycemia in diabetes mellitus (DM) on spatial corneal thickness distribution and to analyze the influence of disease-specific factors. Methods: DM patients and healthy subjects were matched according to age and intraocular pressure (IOP). In diabetics, disease duration, DM type, and HbA1c value were assessed. Spatially resolved corneal thickness was measured by Pentacam HR. Thinnest corneal thickness (TCT) and peripheral pachymetry of concentric circles around TCT were determined. The Dynamic Scheimpflug Analyzer Corvis ST (CST) was used to measure the parameter pachy slope, which is an indicator of the change of corneal thickness from the apex to the periphery. Results: 59 DM patients and 57 healthy subjects were included. Age (P = .486) and IOP (P = .154) were not different between the groups. In DM, pachy slope was significantly higher than in healthy subjects (41.1 ± 9.87 vs. 35.18 ± 10.64 μm, P = .004). Also, the differences between TCT and the average of peripheral corneal thickness of concentric circles with a diameter of 2 mm (10.3 ± 1.7 vs. 9.3 ± 3.8 μm, P < .001) to 6 mm (82.2 ± 12.4 vs. 76.8 ± 12.6 μm, P = .011) were increased in patients. Changes in thickness profile were associated with HbA1c value and presence of diabetic retinopathy or maculopathy. Conclusion: In DM, a stronger peripheral corneal thickness increase was detectable. This change was shown using the novel CST parameter pachy slope and confirmed by Pentacam readings. These alterations might affect IOP and biomechanical measurements, and influence refractive procedures.
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Affiliation(s)
- Lisa Ramm
- Department of Ophthalmology, University Hospital Dresden , Dresden, Germany
| | - Eberhard Spoerl
- Department of Ophthalmology, University Hospital Dresden , Dresden, Germany
| | - Lutz E Pillunat
- Department of Ophthalmology, University Hospital Dresden , Dresden, Germany
| | - Naim Terai
- Department of Ophthalmology, University Hospital Dresden , Dresden, Germany
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Morphological and Optical Determinants of Visual Disability in Fuchs Endothelial Corneal Dystrophy. Cornea 2019; 39:726-731. [DOI: 10.1097/ico.0000000000002236] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fritz M, Grewing V, Maier P, Lapp T, Böhringer D, Reinhard T, Wacker K. Diurnal Variation in Corneal Edema in Fuchs Endothelial Corneal Dystrophy. Am J Ophthalmol 2019; 207:351-355. [PMID: 31415734 DOI: 10.1016/j.ajo.2019.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 08/04/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE The extent of diurnal variation in corneal edema in Fuchs dystrophy is unknown. We measured corneal thickness and posterior profile over the course of the day using Scheimpflug imaging. DESIGN Prospective cohort study. METHODS Participants with clinically advanced Fuchs dystrophy eyes undergoing endothelial keratoplasty and participants with healthy corneas were assessed around noon the day before surgery and late afternoon, in presumed steady state. After controlled overnight patching to standardize eyelid closure, participants were assessed immediately upon eye opening in hospital the morning of surgery. RESULTS Directly upon awakening, patients had mean corneal thickness of 663 μm (interquartile range [IQR], 625-707) in Fuchs dystrophy (n = 44) and controls (n = 11) had thickness of 557 μm (IQR, 527-601). In control corneas, there were no systematic changes with time. In Fuchs dystrophy eyes, corneal thickness decreased after awakening. Ninety-five percent of patients can be expected to have a decrease in corneal thickness over the first 4 hours after awakening between 31 μm and 58 μm (95% prediction interval). Posterior Q decreased on average by 0.15 (95% confidence interval [CI], 0.07-0.23) and posterior radius of curvature decreased by 0.20 mm (95% CI, 0.14-0.27) over the first 4 hours, indicating that edema resolution steepened the central posterior cornea. Beyond 4 hours after awakening, corneas no longer changed considerably in Fuchs dystrophy. CONCLUSION Impaired hydration control in clinically advanced Fuchs dystrophy makes measurements of key corneal parameters unreliable directly after eye opening. Beyond the first hours after eye opening, corneal thickness measurements are unlikely to vary more in Fuchs dystrophy eyes than in normal eyes.
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Muijzer MB, van Luijk CM, van den Bogaerdt AJ, Kruit PJ, Groeneveld‐van Beek E, Melles GR, Wisse RP. Prospective evaluation of clinical outcomes between pre-cut corneal grafts prepared using a manual or automated technique: with one-year follow-up. Acta Ophthalmol 2019; 97:714-720. [PMID: 30803143 PMCID: PMC6850414 DOI: 10.1111/aos.14074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 02/02/2019] [Indexed: 11/28/2022]
Abstract
Purpose Posterior lamellar corneal surgery is considered the standard of care for irreversible endothelial cell dysfunction. Pre‐cut grafts can be prepared either manually (Descemet stripping endothelial keratoplasty; DSEK) or mechanically (Descemet stripping automated endothelial keratoplasty; DSAEK). We performed a head‐to‐head clinical comparison between DSEK and DSAEK grafts. Methods All DSEK and DSAEK procedures performed by two corneal specialists at the University Medical Center Utrecht from 1 January 2016 through 31 October 2016 were prospectively included. Pre‐cut grafts were delivered by two eye banks, which either exclusively prepared the DSEK or DSAEK grafts. Preoperative and postoperative measurements were obtained, and all surgical events and adverse events were recorded. Results A total of 21 DSEK and 53 DSAEK procedures were included for analysis; the two groups were similar at baseline, with the exception of graft endothelial cell density, which was 2531 ± 67 versus 2748 ± 148 cells/mm2, respectively (p < 0.001). At the one‐year follow‐up visit, corrected distance visual acuity and endothelial cell loss were similar between the groups. Mean pachymetry was significantly lower in the DSEK group (521 ± 39 versus 588 ± 59 μm; p < 0.001), whereas the rebubbling rate was significantly higher in the DSEK group (47.6% versus 18.9%; p = 0.001). Finally, three grafts in the DSEK group experienced failure compared to one graft in the DSAEK group (14% versus 1.9%, respectively). Conclusion Manually dissected and microkeratome‐dissected grafts performed similarly with respect to vision and endothelial cell loss assessed one year after surgery. The higher incidence of graft failure among manually dissected (i.e. DSEK) grafts may be attributable to reduced relative thickness compared to DSAEK grafts and/or the resulting differences in tissue handling and the surgeon's learning curve.
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Affiliation(s)
- Marc B. Muijzer
- Utrecht Cornea Research Group Department of Ophthalmology University Medical Center Utrecht Utrecht The Netherlands
| | - Chantal M. van Luijk
- Utrecht Cornea Research Group Department of Ophthalmology University Medical Center Utrecht Utrecht The Netherlands
| | | | - Piet J. Kruit
- Division Cornea Bank ETB‐BISLIFE Beverwijk The Netherlands
| | | | | | - Robert P.L. Wisse
- Utrecht Cornea Research Group Department of Ophthalmology University Medical Center Utrecht Utrecht The Netherlands
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Lee SL, Chen YF, Dong CY. Second harmonic generation imaging reveals asymmetry in the rotational helicity of collagen lamellae in chicken corneas. BIOMEDICAL OPTICS EXPRESS 2019; 10:5223-5234. [PMID: 31646043 PMCID: PMC6788602 DOI: 10.1364/boe.10.005223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 05/03/2023]
Abstract
High tensile strength and optical clarity are unique properties of the cornea. These features are dictated by the three-dimensional architecture of corneal lamellae. Therefore, understanding the microscopic details of the cornea's structural organization may contribute to the development of artificial cornea for the treatment of corneal diseases. In this study, the combination of forward second harmonic generation (SHG) microcopy and fast Fourier-transform based image analysis was used to characterize the depth-dependent superstructure of chicken corneal stroma. Our results show that from the surface, adjacent lamellae of anterior chicken cornea lamella rotate in a counterclockwise direction, and the same rotational helicity is observed in left and right corneas. Furthermore, the overall average rotational pitch of lamellae is 0.92 ± 0.11 degree/µm which persists for 176 ± 14 µm in the anterior stroma. As depth further increased, the rate of lamellar rotation decreases. Upon reaching posterior stroma, lamellar orientation remains constant. Throughout the stroma, collagen lamellae in chicken rotate a total of 169 ± 21 degrees. The lack of lamellar rotation in posterior stroma suggests that packing efficiency cannot be used to explain the helicity of depth-dependent rotation of anterior stroma. In addition, although the right cornea has a higher rotational pitch (0.95 ± 11 vs 0.90 ± 10 degrees/µm) and thinner anterior stroma (173 ± 13 vs 179 ± 14 µm) than the left cornea, the two effects cancel each other out and result in similar total angular rotation of anterior stroma (161 ± 23 and 165 degrees ± 21). Finally, our observation of a total angular rotation of 169 ± 21 degrees shows that within experimental error, chicken cornea lamellae rotate around 180 degrees or half of a complete turn. Additional studies are needed to arrive at an explanation of chicken superstructure in three dimensions.
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Affiliation(s)
- Sheng-Lin Lee
- Department of Physics, National Taiwan University, Taipei 106, Taiwan, China
| | - Yang-Fang Chen
- Department of Physics, National Taiwan University, Taipei 106, Taiwan, China
| | - Chen-Yuan Dong
- Department of Physics, National Taiwan University, Taipei 106, Taiwan, China
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He F, Liu J, Ye P, Wu J, Liang G, Xu W. Biophysical and microstructural changes of swelling cornea caused by endothelial cells damage. Physiol Res 2019; 68:827-833. [PMID: 31424248 DOI: 10.33549/physiolres.934011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Biophysical properties and microstructural changes of swelling cornea which caused by endothelial cells damage will be evaluated. Swelling cornea models were established by endothelial cells damage in 114 Sprague Dawley rats. Relative gray value, swelling rate and light transmittance were measured to evaluated the biophysical properties and microstructure changes were observed by transmission electron microscopy. Relative gray value decreased while swelling rate rose along with time and both of them reached relative stability after 7 days. Light transmittance showed a decline trend with time even after corneal thickness had reached stable stage. Observed by transmission electron microscopy, interfibrillar distance increased, fewer proteoglycans coating appeared and remnants proteoglycan branches became thinner and longer in 7 days. Diameter of fibrils didn't change obviously with time. In cornea edema models caused by endothelial cells damage, the changes of biophysical property and microstructure can help us evaluate corneal edema accurately and objectively.
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Affiliation(s)
- F He
- Eye Center, Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, China.
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Zhang B, Xue Q, Li J, Ma L, Yao Y, Ye H, Cui Z, Yang H. 3D bioprinting for artificial cornea: Challenges and perspectives. Med Eng Phys 2019; 71:68-78. [PMID: 31201014 DOI: 10.1016/j.medengphy.2019.05.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/26/2019] [Accepted: 05/13/2019] [Indexed: 12/13/2022]
Abstract
Corneal disease is one of the most important causes of blindness worldwide. Currently, the dominating treatment of corneal blindness is corneal transplantation. However, the main source of cornea for transplantation is based on donations which is far from enough to meet the requirement (less than 1:70 of cases). The severe shortage of donor cornea promotes the studies of effective corneal alternatives. However, many problems remain and can't be solved in current researches, such as original geometry reconstruction and ocular optical function restoring. 3D bioprinting can be a promising approach for corneal substitution. The advantages of this technology in corneal regeneration enable personalized corneal implant and single or multi-layer corneal equivalents with controllable structure and designed refractive ability. In this review, the progress, applications and limitations of most influential works among current keratoprosthesis and tissue-engineering cornea researches are discussed. Then the applications of 3D bioprinting in manufacturing multi-layered structures and surface are mentioned. Further, the potential, advantages in current research of 3D bioprinting single or multi-layer corneal equivalents and alternatives are discussed. Finally, an insight into the technical challenges and prospective facing the future research of 3D bioprinting corneal alternatives in vivo and in vitro is provided.
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Affiliation(s)
- Bin Zhang
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou (310058), People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Qian Xue
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou (310058), People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Jintao Li
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou (310058), People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Liang Ma
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou (310058), People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, People's Republic of China.
| | - Yufeng Yao
- Department of Ophthalmology, Sir Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qingchun Road East Hangzhou 310016, Zhejiang Province, People's Republic of China
| | - Hua Ye
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, OX1 3PJ, UK
| | - Zhanfeng Cui
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, OX1 3PJ, UK
| | - Huayong Yang
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou (310058), People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, People's Republic of China
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Dual-functional gelatin-capped silver nanoparticles for antibacterial and antiangiogenic treatment of bacterial keratitis. J Colloid Interface Sci 2019; 536:112-126. [DOI: 10.1016/j.jcis.2018.10.041] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 02/08/2023]
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Christaras D, Pennos A, Ginis H, Artal P. Effect of intraocular scattering in macular pigment optical density measurements. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-7. [PMID: 29745133 DOI: 10.1117/1.jbo.23.5.056001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/19/2018] [Indexed: 06/08/2023]
Abstract
Fundus reflectometry is a common in-vivo, noninvasive method to estimate the macular pigment optical density (MPOD). The measured density, however, can be affected by the individual's intraocular scattering. Scattering causes a reduction in the contrast of the fundus image, which in turn leads to an underestimation of the measured density. Intraocular scattering was measured optically in a group of seven young, healthy subjects using the method of optical integration and was subsequently used to correctly estimate the MPOD from fundus images. It was shown that when scattering is not considered, the measured optical density using fundus reflectometry can be underestimated by as high as 16% for our group of subjects.
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Andriotis OG, Desissaire S, Thurner PJ. Collagen Fibrils: Nature's Highly Tunable Nonlinear Springs. ACS NANO 2018; 12:3671-3680. [PMID: 29529373 DOI: 10.1021/acsnano.8b00837] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Tissue hydration is well known to influence tissue mechanics and can be tuned via osmotic pressure. Collagen fibrils are nature's nanoscale building blocks to achieve biomechanical function in a broad range of biological tissues and across many species. Intrafibrillar covalent cross-links have long been thought to play a pivotal role in collagen fibril elasticity, but predominantly at large, far from physiological, strains. Performing nanotensile experiments of collagen fibrils at varying hydration levels by adjusting osmotic pressure in situ during atomic force microscopy experiments, we show the power the intrafibrillar noncovalent interactions have for defining collagen fibril tensile elasticity at low fibril strains. Nanomechanical tensile tests reveal that osmotic pressure increases collagen fibril stiffness up to 24-fold in transverse (nanoindentation) and up to 6-fold in the longitudinal direction (tension), compared to physiological saline in a reversible fashion. We attribute the stiffening to the density and strength of weak intermolecular forces tuned by hydration and hence collagen packing density. This reversible mechanism may be employed by cells to alter their mechanical microenvironment in a reversible manner. The mechanism could also be translated to tissue engineering approaches for customizing scaffold mechanics in spatially resolved fashion, and it may help explain local mechanical changes during development of diseases and inflammation.
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Affiliation(s)
- Orestis G Andriotis
- Institute of Lightweight Design and Structural Biomechanics , Vienna University of Technology , Getreidemarkt 9 , 1060 Vienna , Austria
| | - Sylvia Desissaire
- Institute of Lightweight Design and Structural Biomechanics , Vienna University of Technology , Getreidemarkt 9 , 1060 Vienna , Austria
| | - Philipp J Thurner
- Institute of Lightweight Design and Structural Biomechanics , Vienna University of Technology , Getreidemarkt 9 , 1060 Vienna , Austria
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Comparison of Changes in Central Corneal Thickness During Corneal Collagen Cross-Linking, Using Isotonic Riboflavin Solutions With and Without Dextran, in the Treatment of Progressive Keratoconus. Cornea 2018; 37:340-346. [PMID: 29283924 DOI: 10.1097/ico.0000000000001496] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare intraoperative changes in central corneal thickness (CCT) during corneal cross-linking, using 2 different isotonic riboflavin solutions either with dextran or with hydroxy propyl methylcellulose, in the treatment of progressive keratoconus. METHODS In this retrospective study, we analyzed records of corneal thickness measurements, taken during various steps of cross-linking. Cross-linking was performed using either isotonic riboflavin with dextran (group A) or isotonic riboflavin with hydroxy propyl methylcellulose (without dextran) (group B). CCT measurements were recorded before and after epithelial removal, after saturation with respective isotonic riboflavin solution, after use of hypotonic riboflavin in selected cases, and after ultraviolet A (UV-A) application. A mixed-way analysis of variance was conducted on CCT readings within each group and between both groups, and p < 0.05 was considered significant. RESULTS In group A (100 cases), after saturation with isotonic riboflavin, CCT was decreased by a mean of 51.4 μm (12.1%). In 64%, CCT was <400 μm and additional hypotonic riboflavin was used. After UV-A irradiation, CCT was decreased by a mean of 46.7 μm (11.4%). In group B (100 cases), after saturation with isotonic riboflavin, CCT was increased by a mean of 109.4 μm (26.1%). After UV-A exposure, CCT was increased by a mean of 59.2 μm (11.2%). There was a substantial main effect for time on CCT during corneal cross-linking (CXL), p < 0.001, within both groups. The main effect comparing CCT readings between groups A and B was also significant, p < 0.001. CONCLUSIONS During cross-linking, isotonic riboflavin with dextran causes a significant decrease in corneal thickness, whereas dextran-free isotonic riboflavin causes a significant increase in corneal thickness, thus facilitating the procedure.
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Lepert G, Gouveia RM, Connon CJ, Paterson C. Assessing corneal biomechanics with Brillouin spectro-microscopy. Faraday Discuss 2018; 187:415-28. [PMID: 27051893 DOI: 10.1039/c5fd00152h] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A new Brillouin spectro-microscope was designed and built to investigate the mechanical properties of bovine and human corneas. This instrument integrates a single-stage virtually imaged phased array spectrometer with a novel adaptive-optics interferometric filter to achieve unprecedented rejection of the elastic background signal. As a result, highly-resolved, reproducible data from both thin and thick collagen-based materials were obtained. In particular, this technique is capable of rigorously measuring the relative stiffness of different areas of human corneas, thus providing a true non-contact method to characterise the fundamental mechanical features of both live and fixed biological tissue samples.
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Affiliation(s)
- Guillaume Lepert
- Imperial College London, Blackett Laboratory, London, SW7 2BW, UK.
| | - Ricardo M Gouveia
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Che J Connon
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Carl Paterson
- Imperial College London, Blackett Laboratory, London, SW7 2BW, UK.
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Prina E, Mistry P, Sidney LE, Yang J, Wildman RD, Bertolin M, Breda C, Ferrari B, Barbaro V, Hopkinson A, Dua HS, Ferrari S, Rose FRAJ. 3D Microfabricated Scaffolds and Microfluidic Devices for Ocular Surface Replacement: a Review. Stem Cell Rev Rep 2018; 13:430-441. [PMID: 28573367 DOI: 10.1007/s12015-017-9740-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In recent years, there has been increased research interest in generating corneal substitutes, either for use in the clinic or as in vitro corneal models. The advancement of 3D microfabrication technologies has allowed the reconstruction of the native microarchitecture that controls epithelial cell adhesion, migration and differentiation. In addition, such technology has allowed the inclusion of a dynamic fluid flow that better mimics the physiology of the native cornea. We review the latest innovative products in development in this field, from 3D microfabricated hydrogels to microfluidic devices.
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Affiliation(s)
- Elisabetta Prina
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Pritesh Mistry
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Laura E Sidney
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Jing Yang
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Ricky D Wildman
- Faculty of Engineering, University of Nottingham, Nottingham, UK
| | - Marina Bertolin
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Claudia Breda
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Barbara Ferrari
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Vanessa Barbaro
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy
| | - Andrew Hopkinson
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Harminder S Dua
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Stefano Ferrari
- Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama - Via Paccagnella 11, 30174 Zelarino, Venice, Italy.
| | - Felicity R A J Rose
- Division of Regenerative Medicine and Cellular Therapies, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
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49
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Hayes S, White T, Boote C, Kamma-Lorger CS, Bell J, Sorenson T, Terrill N, Shebanova O, Meek KM. The structural response of the cornea to changes in stromal hydration. J R Soc Interface 2018; 14:rsif.2017.0062. [PMID: 28592658 PMCID: PMC5493790 DOI: 10.1098/rsif.2017.0062] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 05/12/2017] [Indexed: 11/12/2022] Open
Abstract
The primary aim of this study was to quantify the relationship between corneal structure and hydration in humans and pigs. X-ray scattering data were collected from human and porcine corneas equilibrated with polyethylene glycol (PEG) to varying levels of hydration, to obtain measurements of collagen fibril diameter, interfibrillar spacing (IFS) and intermolecular spacing. Both species showed a strong positive linear correlation between hydration and IFS2 and a nonlinear, bi-phasic relationship between hydration and fibril diameter, whereby fibril diameter increased up to approximately physiological hydration, H = 3.0, with little change thereafter. Above H = 3.0, porcine corneas exhibited a larger fibril diameter than human corneas (p < 0.001). Intermolecular spacing also varied with hydration in a bi-phasic manner but reached a maximum value at a lower hydration (H = 1.5) than fibril diameter. Human corneas displayed a higher intermolecular spacing than porcine corneas at all hydrations (p < 0.0001). Human and porcine corneas required a similar PEG concentration to reach physiological hydration, suggesting that the total fixed charge that gives rise to the swelling pressure is the same. The difference in their structural responses to hydration can be explained by variations in molecular cross-linking and intra/interfibrillar water partitioning.
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Affiliation(s)
- Sally Hayes
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Tomas White
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Craig Boote
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Christina S Kamma-Lorger
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.,ALBA Synchrotron Light Source, Cerdanyola del Vallès, Barcelona, Spain
| | - James Bell
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | | | | | | | - Keith M Meek
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
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50
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Kilic Bektas C, Hasirci V. Mimicking corneal stroma using keratocyte-loaded photopolymerizable methacrylated gelatin hydrogels. J Tissue Eng Regen Med 2018; 12:e1899-e1910. [PMID: 29193831 DOI: 10.1002/term.2621] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 10/31/2017] [Accepted: 11/22/2017] [Indexed: 11/06/2022]
Abstract
Cell-laden methacrylated gelatin (GelMA) hydrogels with high (approximately 90%) transparency were prepared to mimic the natural form and function of corneal stroma. They were synthesized from GelMA with a methacrylation degree of 70% as determined by nuclear magnetic resonance. Hydrogels were strong enough to withstand handling. Stability studies showed that 87% of the GelMA hydrogels remained after 21 days in phosphate buffered saline (PBS). Cell viability in the first 2 days was over 90% for the human keratocytes loaded in the gels as determined with the live-dead analysis. Cells in the hydrogel elongated and connected to each other as observed by confocal laser scanning microscopy (CLSM) images and scanning electron microscope analysis after 3 weeks in the culture medium and cells were seen to be distributed throughout the hydrogel bulk. Cells were found to synthesize collagen Types I and V, decorin, and biglycan (representative collagens and proteoglycans of human corneal stroma, respectively) showing that keratocytes maintained their functions and preserved their phenotypes in the hydrogels. Transparency of cell-loaded and cell-free hydrogels after 21 days was found to be over 90% at all time points in the visible light range and was comparable to the transparency of the native cornea. The corneal stroma equivalent produced in this study that has cells entrapped in it leads to a product with homogenous distribution of cells. It was transparent at the very beginning and is expected to allow better vision than nontransparent substrates. It, therefore, has a significant potential to be used as an alternative to the current products used to treat corneal blindness.
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Affiliation(s)
- Cemile Kilic Bektas
- Department of Biological Sciences, METU, Ankara, Turkey.,Department of Biotechnology, METU, Ankara, Turkey.,BIOMATEN, METU Center of Excellence in Biomaterials and Tissue Engineering, Ankara, Turkey
| | - Vasif Hasirci
- Department of Biological Sciences, METU, Ankara, Turkey.,Department of Biotechnology, METU, Ankara, Turkey.,BIOMATEN, METU Center of Excellence in Biomaterials and Tissue Engineering, Ankara, Turkey
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