Journal articles on the topic 'Corneal transplantation'
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1
Salabarria, Ann-Charlott, Manuel Koch, Alfrun Schönberg, Elisabeth Zinser, Deniz Hos, Matthias Hamdorf, Thomas Imhof, Gabriele Braun, Claus Cursiefen, and Felix Bock. "Topical VEGF-C/D Inhibition Prevents Lymphatic Vessel Ingrowth into Cornea but Does Not Improve Corneal Graft Survival." Journal of Clinical Medicine 9, no. 5 (April 28, 2020): 1270. http://dx.doi.org/10.3390/jcm9051270.
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Vascular endothelial growth factor-C/D (VEGF-C/D) regulates lymphangiogenesis. Ingrowth of lymphatic vessels is negatively associated with corneal transplantation success. In this study, we therefore analyzed the effect local blockade of VEGF-C/D has on inflamed corneas. We used the murine model of suture-induced neovascularization and subsequent high-risk corneal transplantation. Mice were treated with a VEGF-C/D trap prior to transplantation. Topical inhibition of VEGF-C/D significantly reduced lymphatic vessel ingrowth, but increased Macrophage numbers in the cornea. Furthermore, corneal transplantation success was not improved by the topical application of the compound. This study demonstrates that local VEGF-C/D inhibition is insufficient to increases corneal transplantation success, likely due to interaction with immune cells.
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Procházková, Alexandra, Martina Poláchová, Jakub Dítě, Magdaléna Netuková, and Pavel Studený. "Chemical, Physical, and Biological Corneal Decellularization Methods: A Review of Literature." Journal of Ophthalmology 2024 (March 25, 2024): 1–17. http://dx.doi.org/10.1155/2024/1191462.
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The cornea is one of the most commonly transplanted tissues worldwide. It is used to restore vision when severe visual impairment or blindness occurs in patients with corneal diseases or after trauma. Due to the global shortage of healthy donor corneas, decellularized corneal tissue has significant potential as an alternative to corneal transplantation. It preserves the native and biological ultrastructure of the cornea and, therefore, represents the most promising scaffold. This article discusses different methods of corneal decellularization based on the current literature. We searched PubMed.gov for articles from January 2009 to December 2023 using the following keywords: corneal decellularization, decellularization methods, and corneal transplantation. Although several methods of decellularization of corneal tissue have been reported, a universal standardised protocol of corneal decellularization has not yet been introduced. In general, a combination of decellularization methods has been used for efficient decellularization while preserving the optimal properties of the corneal tissue.
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Sakowska, Justyna, Paulina Glasner, Maciej Zieliński, Piotr Trzonkowski, and Leopold Glasner. "Corneal Allografts: Factors for and against Acceptance." Journal of Immunology Research 2021 (October 3, 2021): 1–11. http://dx.doi.org/10.1155/2021/5372090.
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Cornea is one of the most commonly transplanted tissues worldwide. However, it is usually omitted in the field of transplantology. Transplantation of the cornea is performed to treat many ocular diseases. It restores eyesight significantly improving the quality of life. Advancements in banking of explanted corneas and progressive surgical techniques increased availability and outcomes of transplantation. Despite the vast growth in the field of transplantation laboratory testing, standards for corneal transplantation still do not include HLA typing or alloantibody detection. This standard practice is based on immune privilege dogma that accounts for high success rates of corneal transplantation. However, the increasing need for retransplantation in high-risk patients with markedly higher risk of rejection causes ophthalmology transplantation centers to reevaluate their standard algorithms. In this review we discuss immune privilege mechanisms influencing the allograft acceptance and factors disrupting the natural immunosuppressive environment of the eye. Current developments in testing and immunosuppressive treatments (including cell therapies), when applied in corneal transplantation, may give very good results, decrease the possibility of rejection, and reduce the need for retransplantation, which is fairly frequent nowadays.
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Ostrovski, D. S., S. A. Borzenok, B. E. Malyugin, O. P. Antonova, M. Kh Khubetsova, and T. Z. Kerimov. "Проблема получения клеточной культуры эндотелиальных клеток роговицы для регенеративных целей." Russian Journal of Transplantology and Artificial Organs 26, no. 2 (January 31, 2024): 135–44. http://dx.doi.org/10.15825/1995-1191-2024-2-135-144.
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Human posterior corneal epithelium (corneal endothelium) has limited proliferative activity both in vivo and in vitro. Disease or dysfunction in these cells leads to impaired corneal transparency of varying degrees of severity, up to blindness. Currently, the only effective standard treatment for corneal endothelial dysfunction is transplantation of donor cornea that contains a pool of healthy and functionally active cells. However, there is a global shortage of donor corneas, which has led to an unmet clinical need and the fact that only 1 patient out of 10 in need receives surgical treatment. Therefore, creation of cellular constructs and artificial human corneas containing healthy endothelium is a very urgent challenge facing modern ophthalmic transplantology. This review presents the current state of affairs, challenges and prospects for obtaining cultured corneal endothelial cells (CECs) in vitro for transplantation purposes.
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Cen, Yu-Jie, Wei Wang, and Yun Feng. "Preliminary studies of constructing a tissue-engineered lamellar corneal graft by culturing mesenchymal stem cells onto decellularized corneal matrix." International Journal of Ophthalmology 14, no. 1 (January 18, 2021): 10–18. http://dx.doi.org/10.18240/ijo.2021.01.02.
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AIM: To construct a competent corneal lamellar substitute in order to alleviate the shortage of human corneal donor. METHODS: Rabbit mesenchymal stem cells (MSCs) were isolated from bone marrow and identified by flow cytometric, osteogenic and adipogenic induction. Xenogenic decellularized corneal matrix (XDCM) was generated from dog corneas. MSCs were seeded and cultured on XDCM to construct the tissue-engineered cornea. Post-transplantation biocompatibility of engineered corneal graft were tested by animal experiment. Rabbits were divided into two groups then underwent lamellar keratoplasty (LK) with different corneal grafts: 1) XDCM group (n=5): XDCM; 2) XDCM-MSCs groups (n=4): tissue-engineered cornea made up with XDCM and MSCs. The ocular surface recovery procedure was observed while corneal transparency, neovascularization and epithelium defection were measured and compared. In vivo on focal exam was performed 3mo postoperatively. RESULTS: Rabbit MSCs were isolated and identified. Flow cytometry demonstrated isolated cells were CD90 positive and CD34, CD45 negative. Osteogenic and adipogenic induction verified their multipotent abilities. MSC-XDCM grafts were constructed and observed. In vivo transplantation showed the neovascularization in XDCM-MSC group was much less than that in XDCM group postoperatively. Post-transplant 3-month confocal test showed less nerve regeneration and bigger cell-absent area in XDCM-MSC group. CONCLUSION: This study present a novel corneal tissue-engineered graft that could reduce post-operatively neovascularization and remain transparency, meanwhile shows that co-transplantation of MSCs may help increase corneal transplantation successful rate and enlarge the source range of corneal substitute to overcome cornea donor shortage.
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Guérin, Louis-Philippe, Gaëtan Le-Bel, Pascale Desjardins, Camille Couture, Elodie Gillard, Élodie Boisselier, Richard Bazin, Lucie Germain, and Sylvain L. Guérin. "The Human Tissue-Engineered Cornea (hTEC): Recent Progress." International Journal of Molecular Sciences 22, no. 3 (January 28, 2021): 1291. http://dx.doi.org/10.3390/ijms22031291.
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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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Brunette, Isabelle, Emilio I. Alarcon, and May Griffith. "Cornea Regeneration as an Alternative to Human Donor Transplantation." European Ophthalmic Review 09, no. 02 (2015): 111. http://dx.doi.org/10.17925/eor.2015.09.02.111.
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There is a need for an alternative to human donor corneas as the availability of good-quality tissues remains limited, with this situation potentially worsening as the population in many countries is progressively ageing. There have been numerous attempts to develop corneal equivalent as alternatives to donated human corneas as well as prostheses. In this short review, we focus on the efforts in bioengineering implants that promote regeneration by Canadian researchers, including our current team of authors. The examples of technologies developed that we describe include biomaterials that allow for partial regeneration of corneal tissue, self-assembled cornea constructs and cell-free corneal implants that promoted regeneration when evaluated in clinical trials in Europe.
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McTiernan, Christopher D., Fiona C. Simpson, Michel Haagdorens, Chameen Samarawickrama, Damien Hunter, Oleksiy Buznyk, Per Fagerholm, et al. "LiQD Cornea: Pro-regeneration collagen mimetics as patches and alternatives to corneal transplantation." Science Advances 6, no. 25 (June 2020): eaba2187. http://dx.doi.org/10.1126/sciadv.aba2187.
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Transplantation with donor corneas is the mainstay for treating corneal blindness, but a severe worldwide shortage necessitates the development of other treatment options. Corneal perforation from infection or inflammation is sealed with cyanoacrylate glue. However, the resulting cytotoxicity requires transplantation. LiQD Cornea is an alternative to conventional corneal transplantation and sealants. It is a cell-free, liquid hydrogel matrix for corneal regeneration, comprising short collagen-like peptides conjugated with polyethylene glycol and mixed with fibrinogen to promote adhesion within tissue defects. Gelation occurs spontaneously at body temperature within 5 min. Light exposure is not required—particularly advantageous because patients with corneal inflammation are typically photophobic. The self-assembling, fully defined, synthetic collagen analog is much less costly than human recombinant collagen and reduces the risk of immune rejection associated with xenogeneic materials. In situ gelation potentially allows for clinical application in outpatient clinics instead of operating theaters, maximizing practicality, and minimizing health care costs.
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Wan, Lu-Qin, Hui-Feng Wang, Chen Chen, Hua Li, Yuan Zhang, Jun-Fa Xue, Qing-Jun Zhou, and Li-Xin Xie. "Efficacy of rhNGF-loaded amniotic membrane transplantation for rabbit corneal epithelial and nerve regeneration." International Journal of Ophthalmology 14, no. 11 (November 18, 2021): 1653–59. http://dx.doi.org/10.18240/ijo.2021.11.02.
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AIM: To evaluate the efficacy of recombinant human nerve growth factor-loaded amniotic membrane (rhNGF-AM) on corneal epithelial and nerve regeneration in rabbit model. METHODS: Freshly prepared human amniotic membrane (AM) were immersed into PBS buffer containing 100 or 500 μg/mL rhNGF for 15, 30, and 60min at 4℃. The in vitro release kinetics of rhNGF was measured with ELISA. For in vivo evaluation, the AM were immersed with 500 μg/mL rhNGF for 30min. Fifty-seven rabbits were selected to establish corneal epithelial defect model. In addition to the 19 rabbits in control group, 38 rabbits received AM transplantation with or without rhNGF after the removal of central epithelium. Corneal epithelial defect area, sub-epithelial nerve fiber density, corneal sensitivity, rhNGF contents in resident AM and corneas were measured after the surgery. RESULTS: rhNGF was sustained release from the AM within 14d in vitro, with the positive correlation with initial immersion concentration. The immersion of AM in 500 μg/mL rhNGF for 30min achieved the most stable release within 14d. After transplantation in rabbit cornea, a high concentration of rhNGF in resident rhNGF-AM and cornea was maintained within 8d. Corneal epithelial healing, nerve fiber regeneration and the recovery of corneal sensitivity were significantly accelerated after the rhNGF-AM transplantation when compared to simple AM transplantation (all P<0.05). CONCLUSION: Simple immersion of AM achieves the sustained release of rhNGF, and promotes corneal epithelial wound healing and nerve regeneration, as well as the recovery of corneal sensitivity in rabbit.
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Qian, Ying, and M. Reza Dana. "Molecular mechanisms of immunity in corneal allotransplantation and xenotransplantation." Expert Reviews in Molecular Medicine 3, no. 18 (July 16, 2001): 1–21. http://dx.doi.org/10.1017/s1462399401003246.
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Corneal allotransplantation is the most common and successful form of solid organ transplantation in humans. In uncomplicated cases, the two-year graft survival rate is over 90%. This extraordinary success can be attributed in part to various features of the normal cornea and anterior segment that together account for their ‘immune-privileged’ status. However, despite this success, a significant number of corneal grafts fail and immunological rejection remains by far the leading cause of graft failure. Studies on animal models of corneal transplantation have yielded a wealth of information on the molecular and cellular features of graft rejection, and have established that this process is mediated primarily by CD4+ T cells of the T helper 1 (Th1) phenotype. In addition, studies have elucidated that certain facets of allosensitisation differ between corneal and other solid organ transplants. On the basis of these findings, novel experimental strategies selectively targeting the afferent or efferent arms of corneal alloimmunity have provided promising results in preventing corneal allograft rejection in the laboratory. Finally, because of the global shortage of human donor corneas, there is currently renewed interest in the possibility of using corneas from other species for transplantation into human eyes (xenotransplantation). Preliminary studies on animal models of corneal xenotransplantation have documented both antibody-mediated and cell-mediated responses that might play important roles in the accelerated rejection observed in corneal xenotransplants. This review synthesises the principal concepts emerging from studies of the molecular mechanisms in corneal transplant immunology.
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Pedro do Valle Varela, João, Lara Gava, Shaira Salvadora Cunha Brito, Renata Vieira Lobo Jardim, Danielle Vieira Praxedes, Paula Borges Meirelles, João Pedro Forechi Rodrigues, Yasmin Oliveira Gil de Almeida, Verena Cruz Orsi, and Fabio Luiz Teixeira Fully. "CORNEAL TRANSPLANTATION." Health and Society 4, no. 02 (April 26, 2024): 264–74. http://dx.doi.org/10.51249/hs.v4i02.2025.
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Corneal transplantation is an ophthalmic surgery that aims to restore vision in patients with corneal diseases. Advances in transplantation techniques and in the treatment of rejection have improved the results of this procedure, making it more effective and safer. This paper seeks to analyze the latest developments in transplantation techniques and treatments for rejection in corneal transplantation, highlighting not only scientific advances, but also the emotional and social aspects involved in this procedure, providing a comprehensive overview of the latest innovations in the field of corneal transplantation, highlighting improvements in surgical techniques and post-operative treatments, which are helping to transform the lives of thousands of patients around the world. This is a bibliographical review, using qualitative premises, with the PubMed, Scopus, Web of Science and Scielo databases. The health descriptors “corneal transplantation”, “corneal graft rejection” and “penetrating keratoplasty” were used to better refine the research. Corneal transplantation is indicated for various conditions, such as keratoconus, corneal dystrophies, corneal opacities, among others. The most common transplant techniques include complete (penetrating) corneal transplantation, anterior lamellar transplantation and endothelial transplantation (DSAEK/ DMEK). In recent years, there have been significant advances in lamellar transplantation techniques, which allow specific layers of the cornea to be replaced while preserving the healthy layers. This has resulted in better success rates and faster visual recovery compared to penetrating transplantation. Treatment of corneal graft rejection includes the use of topical and systemic corticosteroids, immunosuppressants and anti-inflammatory agents. New approaches, such as biological and immunomodulatory therapies, are also being investigated to improve results in cases of refractory graft rejection. In conclusion, corneal transplantation remains an important option for restoring vision in patients with corneal diseases. Updates in transplantation techniques and advances in the treatment of rejection have improved the results of this procedure, providing patients with a better quality of life and faster and more effective visual recovery.
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Staehlke, Susanne, Siddharth Mahajan, Daniel Thieme, Peter Trosan, and Thomas A. Fuchsluger. "Suppressing Pro-Apoptotic Proteins by siRNA in Corneal Endothelial Cells Protects against Cell Death." Biomedicines 12, no. 7 (June 27, 2024): 1439. http://dx.doi.org/10.3390/biomedicines12071439.
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Corneal endothelial cells (CE) are critical for the cornea’s transparency. For severe corneal damage, corneal tissue transplantation is the most promising option for restoring vision. However, CE apoptotic cell death occurs during the storage of donor corneas for transplantation. This study used small interfering (si)RNA-mediated silencing of pro-apoptotic proteins as a novel strategy to protect CE against apoptosis. Therefore, the pro-apoptotic proteins Bax and Bak were silenced in the human corneal endothelial cell line (HCEC-12) by transfection with Accell™siRNA without any adverse effects on cell viability. When apoptosis was induced, e.g., etoposide, the caspase-3 activity and Annexin V-FITC/PI assay indicated a significantly reduced apoptosis rate in Bax+Bak-siRNA transfected HCECs compared to control (w/o siRNA). TUNEL assay in HCECs exposed also significantly lower cell death in Bax+Bak-siRNA (7.5%) compared to control (w/o siRNA: 32.8%). In ex vivo donor corneas, a significant reduction of TUNEL-positive CEs in Bax+Bak-siRNA corneas (8.1%) was detectable compared to control-treated corneas (w/o siRNA: 27.9%). In this study, we demonstrated that suppressing pro-apoptotic siRNA leads to inhibiting CE apoptosis. Gene therapy with siRNA may open a new translational approach for corneal tissue treatment in the eye bank before transplantation, leading to graft protection and prolonged graft survival.
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Patel, Dhaval, Radhika Tandon, Anita Ganger, Aarti Vij, Sanjeev Lalwani, and Adarsh Kumar. "Study of death to preservation time and its impact on utilisation of donor corneas." Tropical Doctor 47, no. 4 (June 13, 2017): 365–70. http://dx.doi.org/10.1177/0049475517713406.
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To evaluate the impact of death-to-preservation time (DPT) on effective utilisation of donor corneas. In a prospective observational study conducted at our tertiary eye centre, donated corneas received over a 15-month period from November 2011 to January 2013 were evaluated. Donor age, donor refrigeration (done or not), DPT, endothelial cell density (ECD), corneal grading, clinical utilisation and surgical outcome after graft transplantation were noted. To analyse the impact of different DPT on donor cornea transplantation, primary outcome measures (corneal grading and endothelial cell density) and secondary outcome measures (primary graft failure and graft infection) were analysed. A total of 990 corneas were assessed. Primary outcomes showed no significant difference for higher DPT ( P > 0.01). ECD, where DPT was >12 h, was better for refrigerated corneas ( P < 0.001). Prolonged DPT had no significant effect on primary graft failure ( P = 0.131) and graft infection ( P = 0.137) in the first month after transplantation. We find that DPT should not be the only criteria to assess the cornea quality; other donor characteristics should be considered equally important. Donor refrigeration should be encouraged in cases where early retrieval is not possible.
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Liu, Yang, Chuanlei Zhang, Yanhui Kong, Huiyu Liu, Cheng Chen, Wenyu Gao, Xiaowei Xi, Hui Yang, and Linhong Deng. "Preparation and Characterization of a Photo-Crosslinked Methacryloyl-Collagen Composite Film to Promote Corneal Nerve Regeneration via Surface Grafting of Taurine Molecules." International Journal of Molecular Sciences 24, no. 14 (July 8, 2023): 11248. http://dx.doi.org/10.3390/ijms241411248.
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Blindness is frequently caused by corneal abnormalities, and corneal transplantation is the most effective treatment method. It is extremely important to develop high-quality artificial corneas because there are not enough donor corneas accessible for cornea transplantation. One of the most-often utilized materials is collagen, which is the primary component of natural cornea. Collagen-based corneal repair materials have good physicochemical properties and excellent biocompatibility, but how to promote the regeneration of the corneal nerve after keratoplasty is still a big challenge. In this research, in order to promote the growth of nerve cells on a collagen (Col) substrate, a novel collagen-based material was synthesized starting from the functionalization of collagen with unsaturated methacryloyl groups that three-dimensionally photopolymerize to a 3D network of chemically crosslinked collagen (ColMA), onto which taurine molecules were eventually grafted (ColMA-Tr). The physicochemical properties and biocompatibility of the Col, ColMA and ColMA-Tr films were evaluated. By analyzing the results, we found that all the three samples had good moisture retention and aq high covalent attachment of methacryloyl groups followed by their photopolymerization improved the mechanical properties of the ColMA and ColMA-Tr. Most importantly, compared with ColMA, the taurine-modified collagen-MA film significantly promoted the growth of nerve cells and corneal epithelial cells on its surface. Our preliminary results suggest that this novel ColMA-Tr film may have potential use in cornea tissue engineering in the future.
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Kandemir, Baran, Nesrin Tutaş Günaydın, Eren Göktaş, and Burak Tanyıldız. "Does Storage Time Affect the Outcomes of Split Corneal Transplantation to Reduce Corneal Donor Shortage? A Retrospective Study." INQUIRY: The Journal of Health Care Organization, Provision, and Financing 58 (January 2021): 004695802110458. http://dx.doi.org/10.1177/00469580211045846.
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Split cornea transplantation can reduce the shortage of donor corneas. Therefore, this study aimed to evaluate the effect of split graft storage time on the outcomes of split corneal transplantation through Descemet membrane endothelial keratoplasty (DMEK) and deep anterior lamellar keratoplasty (DALK) surgeries. Split corneal transplantation was performed in 80 eyes using 41 donor corneas. The mean before and after splitting storage times and total storage times were recorded. Donor corneal buttons and split grafts were stored in short-term solution at 4°C. In both surgeries (DMEK and DALK), donor corneas were divided into groups depending on their storage times. Mean postoperative 12th month best corrected visual acuity (BCVA), endothelial cell density (ECD), endothelial cell loss (ECL), central corneal thickness (CCT), refractive spherical equivalent (RSE), refractive astigmatism, and complication rates were compared among the groups. Correlation between storage times and 1-year BCVA, ECL, and complication rates were assessed. Clinical outcomes of the groups 1 year after the surgeries were also compared. DALK and DMEK were performed in 41 and 39 eyes, respectively. Storage times were not correlated with 1-year DMEK outcomes and only weakly correlated with post-DALK ECD, ECL, and RSE values. Except for CCT in those that underwent DALK, the outcomes of DMEK and DALK surgeries with stored and non-stored split grafts were not significantly different ( P = .02). The storage times of donor corneas and split grafts do not have any impact on outcomes.
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Xie, Hua-Tao, Dan Zhao, Yang Liu, and Ming-Chang Zhang. "Umbilical Cord Patch Transplantation for Corneal Perforations and Descemetoceles." Journal of Ophthalmology 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/2767053.
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Purpose. To evaluate the clinical outcome of umbilical cord patch (UCP) transplantation for deep corneal ulcers with perforations and descemetoceles. Methods. In this retrospective, noncomparative, interventional case series, 11 eyes of 11 patients with corneal perforation or descemetocele were included. The thickness and microstructure of UCP were measured. All eyes were treated with UCP and amniotic membrane transplantation for corneal reconstruction. Corneal ulcer healing, corneal thickness, anterior chamber formation, and best-corrected visual acuity (BCVA) were recorded and analyzed. Results. The thickness of human UCP is 398.6 ± 102.8 μm (n=5) with compact aligned fibers. The average age was 56.2 ± 15.8 (ranging from 22 to 75) years. The mean follow-up period was 7.1 ± 1.7 (ranging from 5 to 10) months. Four patients had descemetocele and 7 had perforation. The anterior chambers in all the 7 perforated corneas were formed at postoperative day 1. All patients regained a normal corneal thickness and smooth corneal surface within the first postoperative month. The vision improved in 10 eyes and remained unchanged in 1 eye. No recurrence nor side effects occurred during the follow-up. Conclusions. UCP can serve as an alternative material in the treatment of corneal perforations and descemetoceles. This treatment option is also beneficial in those countries with limited cornea donors and eye bank services.
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Singh, Sujaya, Reena Kaur, Marium Jamaluddin, and Azida Juana. "ONE CORNEA TWO RECIPIENTS: FEEDING TWO BIRDS WITH ONE SCONE." Journal of Health and Translational Medicine 26, no. 1 (April 10, 2023): 5–8. http://dx.doi.org/10.22452/jummec.vol26no1.2.
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The existing shortage of local donor corneas in our institution (University Malaya) and Malaysia, in general, prompted us to attempt the use of one donor cornea for two transplantation procedures; Descemet Stripping Endothelial Keratoplasty (DSEK) in a case of a pseudophakic bullous keratopathy (PBK) with underlying Fuchs endothelial dystrophy (FED) and lamellar patch graft in a case of limbal dermoid. The donor cornea was divided into anterior and posterior lamellae manually. The anterior corneal button was used as a patch graft for anterior lamellar keratoplasty in a 6-year-old patient with limbal dermoid, and the posterior corneal button was used for a DSEK procedure in a 68-year-old patient with corneal decompensation. Both patients had a stable and good visual outcome throughout a 1-year postoperative period. This allows the use of one corneal tissue by more than one recipient to overcome the shortage in donor corneas.
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Shen, Lin, Peng Sun, Liqun Du, Jing Zhu, Chengqun Ju, Hui Guo, and Xinyi Wu. "Long-Term Observation and Sequencing Analysis of SKPs-Derived Corneal Endothelial Cell-Like Cells for Treating Corneal Endothelial Dysfunction." Cell Transplantation 30 (January 1, 2021): 096368972110178. http://dx.doi.org/10.1177/09636897211017830.
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Corneal endothelial dysfunction is a principal cause of visual deficiency. Corneal transplantation is the most effective treatment for corneal endothelial dysfunction. However, a severe shortage of available donor corneas or human corneal endothelial cells (HCECs) remains a global challenge. Previously, we acquired corneal endothelial cell-like cells (CEC-like cells) derived from human skin-derived precursors (SKPs). CEC-like cells were injected into rabbit and monkey corneal endothelial dysfunction models and exerted excellent therapeutic effect. In this study, we prolonged the clinical observation in the monkey experiment for 2 years. Polymerase chain reaction (PCR) and DNA sequencing were carried out to confirm the existence of CEC-like cells. Histological examinations were carried out to show the corneal morphology. Further transcriptome sequencing was also carried out on HCEC, CEC-like cells before transplantation and after transplantation. We found that the monkeys cornea remained transparent and normal thickness. The total endothelial cell density decreased gradually, but tended to be stable and remained in a normal range during 2-year observation. The CEC-like cells persist during observation and could adapt to the microenvironment after transplantation. The gene expression pattern of CEC-like cells was similar to HCEC and changed slightly after transplantation. In conclusion, this study presented a brand-new insight into CEC-like cells and further provided a promising prospect of cell-based therapy for corneal endothelial dysfunction. The renewable cell source, novel derivation method and simple treatment strategy may be clinically applied in regenerative medicine in the future.
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Hashimoto, Yoshihide. "Research and development on therapeutic materials for corneal stromal disease consisting of transparent decellularised porcine corneas." Impact 2023, no. 3 (September 21, 2023): 49–51. http://dx.doi.org/10.21820/23987073.2023.3.49.
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Investigations to discover potential corneal stromal substitutes to effectively treat corneal stromal disease tend to focus on transparent and bio-inert synthetic polymer materials and hydrogel materials. More recent studies are looking at alternative therapeutic materials that utilise corneas from pigs. Assistant Professor Yoshihide Hashimoto, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Japan, is part of a team developing functional materials and therapeutic techniques to restore the function of damaged biological tissues and organs based on biomaterials and bioengineering. At present, the researchers are focused on restoring the function of corneas, but the research has the potential for broader applications. After blindness caused by clouding or shape change, corneal transplantation is the only effective treatment but there is a worldwide shortage of donated human corneas. To establish an advanced treatment for corneal diseases in combination with cell therapy, reliable artificial corneal stroma is required and Hashimoto and the team are exploring the potential of highly transparent decellularised porcine cornea for the treatment of corneal stroma disease. This has potential to overcome the issues associated with existing treatments and can also be developed for reconstruction of full-thickness cornea. In decellularised corneas, cellular components are removed from animal-derived corneal tissue. The method the team is using does not use surfactants, which means the functional proteins and tissue structure can be retained.
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Hsiao, Ching-Hsi, Yih-Shiou Hwang, Wen-Yu Chuang, David H. K. Ma, Lung-Kun Yeh, Shin-Yi Chen, and Jwu-Ching Shu. "Prevalence and clinical consequences of cytomegalovirus DNA in the aqueous humour and corneal transplants." British Journal of Ophthalmology 103, no. 5 (June 28, 2018): 666–71. http://dx.doi.org/10.1136/bjophthalmol-2018-312196.
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AimTo determine the prevalence and clinical consequences of cytomegalovirus (CMV) DNA in the aqueous and corneal tissues obtained at the time of corneal transplantation to evaluate the diagnostic value of PCR analysis in identifying patients at risk of postkeratoplasty CMV endotheliitis.MethodsThirty patients who underwent corneal transplantation were included in 2011. The aqueous, excised recipient corneas and donor corneoscleral rims were analysed by PCR for the presence of CMV DNA. The medical records of the patients were retrospectively reviewed and linked with PCR results.ResultsCMV DNA was detected in three (10%) aqueous, eight (26.7%) recipient corneas and six (20.0%) donor corneas obtained during keratoplasty from the 30 patients. Postoperatively, four patients, who had CMV DNA in either aqueous (3) or recipient cornea (1), were diagnosed with CMV endotheliitis based on clinical features and repeat aqueous tapping for real-time PCR analysis. At the median 60.5 months follow-up, 8 (72.7%), including 4 with postkeratoplasty CMV endotheliitis, of the 11 patients with CMV positivity in any one sample had graft failure, while 9 (47.3%) of the 19 patients without evidence of CMV DNA experienced graft failure.ConclusionsWe found a relatively high prevalence of CMV DNA in the aqueous and corneas obtained during keratoplasty. All the patients who had CMV positivity in aqueous developed CMV endotheliitis postoperatively and experienced graft failure eventually. Aqueous tapping at the time of corneal transplantation for PCR analysis may help to improve the diagnosis and follow-up management of postkeratoplasty CMV endotheliitis.
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Pereira Cruz, Giovanna Karinny, Marcos Antonio Ferreira Júnior, Oleci Pereira Frota, Elen Ferraz Teston, Viviane Euzébia Pereira Santos, Allyne Fortes Vitor, Mayk Penza Cardoso, and Fábio Rogério Rodrigues Leocates de Moraes. "Cornea donation process and tissue quality for transplantation." PLOS ONE 16, no. 4 (April 20, 2021): e0249927. http://dx.doi.org/10.1371/journal.pone.0249927.
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Introduction The quality of the corneal tissue can be influenced by several factors inherent to the recipient, donor, and to the donation and transplantation process. The donated corneal tissue can be classified by its quality as excellent, good, regular, bad, or unacceptable for transplantation, evaluating it in a slit lamp. Objective To analyze the relationship between the clinical and sociodemographic variables of the donors and the donation process and the classification of the quality of the corneal tissue collected for transplantation. Methods This is an epidemiologic study, retrospective cohort type, which addressed the process of cornea donation by the Human Eye Tissue Bank in a reference service in Northeast Brazil. The sample consisted of corneas processed by the Human Eye Tissue Bank of Rio Grande do Norte (n = 419). For descriptive and inferential analysis, the study used the Statistical Package for the Social Sciences (SPSS) software, version 25.0, and considered a significance level of 0.05. Logistic regression analysis was used for the adjustment of the final model. Results It was verified that the epidemiological profile showed a prevalence of individuals with a mean age of 42.54 years old, male (73.99%), and living in the metropolitan region of the state capital (75.66%). When analyzing the relationship between the clinical and sociodemographic variables of the donors, it was identified that those aged 45 years old or less had better quality corneas (excellent and good), while the chronological variables were predictive factors for corneas of regular and bad qualities. Conclusion The identification of the factors inherent to the donation process and predictors of corneal tissue quality contribute to minimizing the risk of transplantation and to a better ocular prognosis.
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Tan, Donald TH, Arundhati Anshu, and Jodhbir S. Mehta. "Paradigm Shifts in Corneal Transplantation." Annals of the Academy of Medicine, Singapore 38, no. 4 (April 15, 2009): 332–39. http://dx.doi.org/10.47102/annals-acadmedsg.v38n4p332.
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Conventional corneal transplantation, in the form of penetrating keratoplasty (PK), involves full-thickness replacement of the cornea, and is a highly successful procedure. However, the cornea is anatomically a multi-layered structure. Pathology may only affect individual layers of the cornea, hence selective lamellar surgical replacement of only the diseased corneal layers whilst retaining unaffected layers represents a new paradigm shift in the field. Recent advancements in surgical techniques and instrumentation have resulted in several forms of manual, microkeratome and femto-second laser-assisted lamellar transplantation procedures. Anterior lamellar keratoplasty (ALK) aims at replacing only diseased or scarred corneal stroma, whilst retaining the unaffected corneal endothelial layer, thus obviating the risk of endothelial allograft rejection. Posterior lamellar keratoplasty/endothelial keratoplasty (PLK/EK) involves the replacement of the dysfunctional endothelial cell layer only. Whilst significant technical and surgical challenges are involved in performing lamellar micro-dissection of a tissue which is only 0.5 mm thick, the benefits of a more controlled surgical procedure and improved graft survival rates have resulted in a shift away from conventional PK. This review details the current advances in emerging lamellar corneal surgical procedures and highlights the main advantages and disadvantages of these new lamellar corneal procedures. Key words: Deep anterior lamellar keratoplasty, Descemet’s stripping endothelial keratoplasty, Endothelial keratoplasty, Lamellar keratoplasty, Penetrating keratoplasty
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Kobashigawa, K. K., B. C. Martins, M. C. B. Massoli, T. H. Ishizawa, R. P. Schocken-Iturrino, D. E. Brooks, and J. L. Laus. "Microbiological profile of donor corneas stored for tectonic transplantation purposes in rabbits." Arquivo Brasileiro de Medicina Veterinária e Zootecnia 65, no. 1 (February 2013): 61–66. http://dx.doi.org/10.1590/s0102-09352013000100010.
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This study aimed to evaluate the microbiota of donor rabbit corneas stored for tectonic transplantation purposes. Swabs from both corneas of 20 rabbits were carefully collected and submitted to microorganism isolation and identification. After this first swab collection, rabbits were euthanized for reasons other than this project and the eyes were enucleated. The corneas were collected and stored to compose the cornea tissue bank. Corneas were stored in a 0.3% tobramycin solution at -20ºC. After 30 days, the corneas were thawed at room temperature and removed from the antibiotic. New swabs were obtained from the corneas and submitted to microorganism isolation and identification. Gram positive organisms were predominant in the rabbit corneal flora before storage and the Staphylococcus sp. was the most common microorganism isolated from those samples. No growth was observed on the samples collected after storage. The methods used for collection and storage of the corneas were efficient to constitute a sterile donor corneal tissue bank.
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ALBON, JULIE. "CORNEAL TRANSPLANTATION AND THE ARTIFICIAL CORNEA." Journal of Mechanics in Medicine and Biology 03, no. 01 (March 2003): 95–106. http://dx.doi.org/10.1142/s0219519403000636.
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The clinical need for an alternative to donor corneal tissue has encouraged much interest in recent years. An artificial cornea whether it be bio-engineered or a synthetic keratoprosthesis must fulfill the functions of the cornea it replaces: transparent, refractive surface, protection, non-immunogenic. A wide range of implants and biomedical devices have been developed in an attempt to correct corneal blindness. Limitation of existing biomaterials are evident when reviewing keratoprosthesis surgery complications. These include infection, intraocular inflammation, retromembrane formation, inadequate interface seal thus epithelial downgrowth and glaucoma. Attempts to improve healing in such cases have involved using various polymers or tissues to surround the optic. The successes and failures of synthetic prostheses that have been implanted in humans is discussed. More recently, the idea of a bio-engineered cornea has arisen. Tissue-engineering involves the manipulation of cells using in vitro techniques to create a composite tissue, which could then be implanted in vivo. Corneal equivalents have been reconstructed from corneal cell lines. They already have their potential uses in the biomedical world: as replacements for animals in toxicology testing and pharmacological studies, as well as in basic research into cell-cell and cell-matrix interactions of corneal wound healing. Current research is ongoing to determine if the bio-engineered cornea will have a role in corneal transplant surgery.
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Jung, Il, and Byung Yi Ko. "Analysis in Results of Microbiologic Exam Related to Donor Corneas." Journal of the Korean Ophthalmological Society 63, no. 3 (March 15, 2022): 236–41. http://dx.doi.org/10.3341/jkos.2022.63.3.236.
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Purpose: This study analyzed the microorganisms identified in donor corneas and their clinical significance.Methods: The medical records of 94 patients (114 eyes) who underwent keratoplasty and microbiological tests of the donor corneas from October 2008 to December 2020 at our hospital were reviewed retrospectively. During keratoplasty, we conducted microbiological tests of the corneoscleral rim of the donor cornea and preserving solution Optisol™-GS (Bausch & Lomb, Rochester, NY, USA), and examined the antibiotic susceptibility of bacterial isolates from the cultures.Results: Some isolates of domestic donor corneas revealed bacteria, but none of the imported corneas did. Gram-negative bacilli were detected from the corneoscleral rim in three eyes (2.6%): two cases of Acinetobacter baumannii/haemolyticus and one case of Pseudomonas aeruginosa. In one case (0.9%), Acinetobacter baumannii/haemolyticus was identified from preserving solution, with no bacteria found in the corneoscleral rim. Antibiotic susceptibility tests showed multi-drug resistance, except to colistin. In all cases where bacteria were detected, there was no keratitis or endophthalmitis after corneal transplantation.Conclusions: Although rare, bacteria can be identified from donor corneas or the preserving solution used in corneal transplantation. Therefore, caution is needed in all processes dealing with donor corneas. Empirical antibiotics that have sufficient antimicrobial activity to suppress multi-drug resistant bacteria should be selected in corneal transplantation.
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Silina, Elina, and Guna Laganovska. "Total Corneal Transplantation after Trauma." Acta Chirurgica Latviensis 17, no. 2 (December 20, 2017): 37–38. http://dx.doi.org/10.1515/chilat-2017-0023.
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Abstract The first successful corneal transplantation is known since 1905, performed by Eduard Zirm (2). It has been implemented in order to restore vision in a variety of corneal diseases and after ocular traumas. The traditional technique for corneal transplantation, penetrating keratoplasty (PKP), refers to the full-thickness replacement of corneal tissue with a healthy donor graft (1). Authors report a well-documented case about successfully transplanted cornea after penetrating ocular trauma to improve visual outcome.
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Ahmedov, A. K., T. Z. Kerimov, Kh D. Tonaeva, B. E. Malygin, and S. A. Borzenok. "Technology for obtaining an ultrathin posterior lamellar corneal graft at the Eye Tissue Bank." Russian Journal of Transplantology and Artificial Organs 22, no. 3 (October 6, 2020): 167–73. http://dx.doi.org/10.15825/1995-1191-2020-3-167-173.
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Objective: to develop technologies for preoperative preparation of the posterior lamellar corneal graft based on our own formulation of the preservation medium for optimal dehydration of the donor cornea and a technique for cutting out an ultrathin flap using an optimized method at the Eye Tissue Bank. Materials methods. In a series of experimental studies, we obtained data on the hydration level of cadaveric donor corneas that were preserved in various solutions at different observation periods. Using 16 corneas, analytical weighing and pachymetry were performed via optical coherence tomography in the experimental (n = 8) and control (n = 8) groups. Morphological and functional characteristics of the corneal endothelium were then assessed. At the next stage of work, ultrathin grafts were formed from 16 corneas after hypothermic preservation in the experimental (n = 8) and control (n = 8) solutions by single-pass microkeratome, followed by microscopy of the samples using a scanning electron microscope. Results. After the first days of preservation in the proposed solution, there was dehydration of 9% cornea in the experimental group in comparison with the samples of the control group. After 4 days of preservation, there was no reliable difference found between the groups (p > 0.05) in the study of the endothelial cell viability of ultra-thin corneal grafts by immunofluorescent microscopy using the «Live and dead» marker. Scanning electron microscopy revealed that corneal stromal collagen fibers, preserved in the proposed medium, retained their integrity. Conclusion. The proposed technology can be recommended for use at eye banks for formation of an ultra-thin corneal graft at the preoperative stage.
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Ostadian, Farshad, Mahmoud Reza Panahi Bazzaz, Vahid Shahsavari, and Mohammad Sadegh Mirdehghan. "Evaluation of operations and causes of corneal transplantation in patients referred to the ophthalmology ward of Imam Khomeini Hospital in Ahvaz 2003 to 2019." Jundishapur journal of Medical Sciences 21, no. 6 (July 1, 2023): 846–58. http://dx.doi.org/10.32598/jsmj.21.6.2787.
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Introduction: Corneal transplantation is one of the most common eye surgeries and the most common and successful tissue transplant in the world. The aim of this study was to determine the frequency of causes and types of corneal transplantation in patients referred to the ophthalmology ward of Imam Khomeini Hospital in Ahvaz from 2003 to 2018. Methods: This descriptive study was performed on the records of the patients who underwent corneal transplantation. The information included age, sex, cause of transplantation, sex and age of the donor, need for re-transplantation, reason for re-transplantation, laterality of cornea and the type of operation. Results: The mean age of patients receiving cornea was 50.93 years and included 491 (49.3%) male and 505 (50.7%) female. 51.7% of corneal transplant operations were related to the right eye and 47.9% of the operations were related to the left eye respectively. PBK was the most cause of corneal transplantation. Most patients underwent corneal transplantation by PK and then DSAEK. Conclusion: Frequency of PBK was increased in this study as compare to other previous studies which may be due to significant increase in the rate of phacoemulsification surgeries. DSEAK and DMEAK have become more accepted and favorable surgeries in the case of corneal endothelial disease. Based on new surgical techniques and advances in post of management we suggest, new meta-analysis study to evaluate associated diseases , comparison of the regraft rate in different surgical techniques and post op management of them.
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Orash Mahmoud Salehi, Amin, Saeed Heidari-Keshel, Seyed Ali Poursamar, Ali Zarrabi, Farshid Sefat, Narsimha Mamidi, Mahmoud Jabbarvand Behrouz, and Mohammad Rafienia. "Bioprinted Membranes for Corneal Tissue Engineering: A Review." Pharmaceutics 14, no. 12 (December 14, 2022): 2797. http://dx.doi.org/10.3390/pharmaceutics14122797.
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Corneal transplantation is considered a convenient strategy for various types of corneal disease needs. Even though it has been applied as a suitable solution for most corneal disorders, patients still face several issues due to a lack of healthy donor corneas, and rejection is another unknown risk of corneal transplant tissue. Corneal tissue engineering (CTE) has gained significant consideration as an efficient approach to developing tissue-engineered scaffolds for corneal healing and regeneration. Several approaches are tested to develop a substrate with equal transmittance and mechanical properties to improve the regeneration of cornea tissue. In this regard, bioprinted scaffolds have recently received sufficient attention in simulating corneal structure, owing to their spectacular spatial control which produces a three-cell-loaded-dimensional corneal structure. In this review, the anatomy and function of different layers of corneal tissue are highlighted, and then the potential of the 3D bioprinting technique for promoting corneal regeneration is also discussed.
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Malyugin, B. E., S. A. Borzenok, O. P. Antonova, D. S. Ostrovskii, and Z. R. Ebzeeva. "Transplantation of endothelial cell suspension in an ex vivoexperiment." Fyodorov journal of ophthalmic surgery, no. 4 (December 28, 2023): 86–92. http://dx.doi.org/10.25276/0235-4160-2023-4-86-92.
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Relevance. Corneal transplantation with entire cornea or anormal layers replacement remains the only treatment option for patients with corneal endothelium pathology. Selective endothelial replacement was introduced into practice two decades ago, namely posterior lamellar keratoplasty, which has advantages over penetrating keratoplasty. Improvements of this method led to technique creation where isolated Descemet's membrane with endothelium monolayer without stromal layer is transplanted. This technology is associated with risks of intra- and postoperative complications, and is difficult to perform. Nowadays, development is in progress of introducing corneal endothelial cells (CECs) transplantation without stromal layer and even without Descemet's membrane. CECs transplantation in suspension form has potential to change treatment approach of corneal endothelium pathologies giving possibility of rapid eyesight recovery and reducing need for graft material. Purpose. To evaluate effectiveness of corneal CECs suspension transplantation on cadaver eye in ex vivo experiment. Material and methods. CECs suspension was obtained by modified enzymatic method. CECs transplantation experiment consisted of 3 stages. Firstly, CECs loss was calculated depending on cell administration method. Secondly, corneoscleral button was used as recipient for the obtained suspension. The third stage was carried out on cadaver eyeball. Results. The viability of transplanted CECs and their effective adhesion to Descemet's membrane was confirmed in this experiment. The characteristic markers of CECs ZO-1, Na+/K+ -ATPase, Ki67 were determined in corneal samples by immunohistochemistry assay and single cells expressing Vimentin were detected after one-week cultivation. Conclusion. Based on transplantation experiment results, it can be noted this technique is quite promising in surgical rehabilitation of patients with corneal endothelial dysfunction. Thus, it seems relevant to continue research to achieve the main goal – to fully cover the defect of central zone of corneal posterior surface with isolated CECs given that their morphology and functional activity are preserved. Key words: cornea, endothelial corneal dystrophy, endothelial cell suspension, corneal endothelial cell transplantation
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Oganesyan, Oganes G., S. S. Yakovleva, M. P. Kharlampidi, and A. A. Grdikanyan. "The rationale application of donor material: original ten years experience, possible ways of development and literature data." Medical Journal of the Russian Federation 22, no. 4 (August 15, 2016): 193–97. http://dx.doi.org/10.18821/0869-2106-2016-22-4-193-197.
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Lately, layer-wise keratoplasty became the first operation of choice in case of pathology of cornea. In view of satisfying results of endothelial surgery similar operations are implemented at earlier stages that increases need in donor tissue. With increasing of life span of population, also increases number of patients in need of transplantation of cornea. The number of intact cadaver cornea decreases because of stable increase of surgical interventions on front segment of eye. The present article presents original ten years experience concerning optimization of application of donor tissue and indicate on possibilities of further increasing of number of applied keratoplasties. From 2009 to 2015 in the Helmholtz Moscow research institute of eyes diseases 652 transplantations of cornea were implemented in various modifications: straight-through keratoplasty, transplantation of Descemet's membrane with endothelium (DMEK), deep front layer-wise keratoplasty, endokeratoplasty (DSEK) with various modes of transplant formation and 23 frontal layer-wise keratoplasties. In transplantation were also used eyes of donors with radial keratotomy, after laser keratomileusis and with artificial intra-ocular lens. To implement 652 operations 528 cadaver eyes with average age 41 ± 32,5 years (varying from 21 to 87 years) were required. The number of transplantations increased approximately on 50% at potential up to 75%. The lamellar surgery permits using corneal donor tissue with altered frontal surface and to increase number of transplantations of cornea. The renunciation of application of corneal donor tissue with altered frontal surface is inexpedient.
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Bachmann, Björn. "Ripasudil zur antiangiogenen Therapie bei Keratoplastik." Kompass Ophthalmologie 7, no. 3 (2021): 128–29. http://dx.doi.org/10.1159/000518817.
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Corneal allograft survival is mediated by the variety of immunological reactions and wound healing process. Our aim was to explore the effects of topical administration of ripasudil, a selective Rho-associated coiled-coil protein kinase inhibitor, on corneal allograft survival. Ripasudil was administered to mice thrice a day after allogeneic corneal transplantation. Corneal graft survival, opacity, neovascularization, re-epithelization, immune cell infiltration, and mRNA levels of angiogenic and pro-inflammatory factors in the grafted cornea and draining lymph nodes (dLNs) were evaluated with slit-lamp microscopy, immunohistochemistry, flow cytometry, and polymerase chain reaction. Graft survival was significantly prolonged with lower graft opacity and neovascularization scores in 0.4% and 2.0% ripasudil-treated groups, and mRNA levels of angiogenic and pro-inflammatory factors in ripasudil-treated grafted corneas were reduced. Moreover, 0.4% and 2.0% ripasudil reduced CD45<sup>+</sup>-infiltrated leukocyte frequency, <i>Cd11b</i> and <i>Cd11c</i> mRNA levels, and the frequencies of mature dendritic cells, IFNγ-, and IL-17- producing CD4<sup>+</sup>T cells in the dLNs of recipients. Re-epithelization rate of the grafted cornea was significantly higher in the 0.4% and 2.0% ripasudil groups than in the control. Topically applied ripasudil prolonged graft survival by downregulating neovascularization and inflammation factors, while promoting corneal re-epithelization, suggesting that ripasudil may be useful for suppressing immunological rejection in corneal transplantation.
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Chen, Yingxin, Congling Liao, Minghong Gao, Michael Wellington Belin, Mingwu Wang, Hai Yu, and Jing Yu. "Efficacy and Safety of Corneal Transplantation Using Corneas from Foreign Donors versus Domestic Donors: A Prospective, Randomized, Controlled Trial." Journal of Ophthalmology 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/178289.
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Purpose. To assess the efficacy and safety of corneal transplantation using corneas from foreign donors.Methods. One hundred and eight patients needing therapeutic penetrating keratoplasty were randomly divided into 2 groups (54 cases/group): foreign group using foreign donor corneas and domestic group using domestic donor corneas. Clinical outcome and incidence of postoperative complications were compared between groups.Results. No significant difference with respect to the therapeutic outcome and postoperative Best Corrected Visual Acuity (BCVA) and neovascularization by final follow-up was observed between the two groups. The graft thickness in the foreign group was statistically higher than the domestic group at 1 month postoperatively, but not at 3, 6, and 12 months postoperatively. Corneal endothelial cell density in the domestic group was statistically higher than in the foreign group at 3, 6, and 12 months postoperatively. Corneal epithelial abnormalities in the foreign group were significantly higher than that in domestic group. The primary graft failure, incidence of graft survival, and postoperative complications such as immunologic rejection, graft infection, and secondary glaucoma were not significantly different between the two groups.Conclusions. Corneal transplantations using foreign donor corneas are as effective and safe as those using domestic donor corneas.
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Clahsen, Thomas, Christian Büttner, Niloofar Hatami, André Reis, and Claus Cursiefen. "Role of Endogenous Regulators of Hem- And Lymphangiogenesis in Corneal Transplantation." Journal of Clinical Medicine 9, no. 2 (February 9, 2020): 479. http://dx.doi.org/10.3390/jcm9020479.
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Under normal conditions, the cornea, being the transparent “windscreen” of the eye, is free of both blood and lymphatic vessels. However, various diseases of the eye, like infections, can interfere with the balance between promoting and inhibiting factors, which leads to ingrowth of blood and lymphatic vessels. The newly formed lymphatic vessels increase the risk of graft rejection after subsequent corneal transplantation. Corneal transplantation is one of the most commonly performed transplantations worldwide, with more than 40,000 surgeries per year in Europe. To date, various anti-hem- and anti-lymphangiogenic treatment strategies have been developed specifically for the corneal vascular endothelial growth factor (VEGF) pathway. Currently, however, no treatment strategies are clinically available to specifically modulate lymphangiogenesis. In this review, we will give an overview about endogenous regulators of hem- and lymphangiogenesis and discuss potential new strategies for targeting pathological lymphangiogenesis. Furthermore, we will review recently identified modulators and demonstrate that the cornea is a suitable model for the identification of novel endogenous modulators of lymphangiogenesis. The identification of novel modulators of lymphangiogenesis and a better understanding of the signaling pathways involved will contribute to the development of new therapeutic targets for the treatment of pathological lymphangiogenesis. This, in turn, will improve graft rejection, not only for the cornea.
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Fuest, Matthias, Gary Hin-Fai Yam, Jodhbir S. Mehta, and Daniela F. Duarte Campos. "Prospects and Challenges of Translational Corneal Bioprinting." Bioengineering 7, no. 3 (July 6, 2020): 71. http://dx.doi.org/10.3390/bioengineering7030071.
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Corneal transplantation remains the ultimate treatment option for advanced stromal and endothelial disorders. Corneal tissue engineering has gained increasing interest in recent years, as it can bypass many complications of conventional corneal transplantation. The human cornea is an ideal organ for tissue engineering, as it is avascular and immune-privileged. Mimicking the complex mechanical properties, the surface curvature, and stromal cytoarchitecure of the in vivo corneal tissue remains a great challenge for tissue engineering approaches. For this reason, automated biofabrication strategies, such as bioprinting, may offer additional spatial control during the manufacturing process to generate full-thickness cell-laden 3D corneal constructs. In this review, we discuss recent advances in bioprinting and biomaterials used for in vitro and ex vivo corneal tissue engineering, corneal cell-biomaterial interactions after bioprinting, and future directions of corneal bioprinting aiming at engineering a full-thickness human cornea in the lab.
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Parker, Jack, Philip Dockery, Ana Preda-Naumescu, Martine Jager, Korine van Dijk, Isabel Dapena, and Gerrit Melles. "Descemet Membrane Endothelial Keratoplasty and Bowman Layer Transplantation: An Anatomic Review and Historical Survey." Ophthalmic Research 64, no. 4 (2021): 532–53. http://dx.doi.org/10.1159/000516093.
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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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Kusano, Mao, Yasser Helmy Mohamed, Masafumi Uematsu, Daisuke Inoue, Kohei Harada, Diya Tang, and Takashi Kitaoka. "Whole Corneal Descemetocele." Medicina 59, no. 10 (October 6, 2023): 1780. http://dx.doi.org/10.3390/medicina59101780.
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Background and Objectives: To report a case of microbial keratitis complicated by severe corneal melting and whole corneal descemetocele. Methods: A 72-year-old male farmer presented with a right corneal ulcer involving nearly the entire cornea, which was almost completely melted down with the remaining Descemet’s membrane (DM). The pupil area was filled with melted necrotic material, with the intraocular lens partially protruding from the pupil and indenting the DM. Corneal optical coherence tomography (OCT) examination revealed a corneal thickness of 37 µm that was attached to its back surface, with the iris and a part of the intraocular lens (IOL) protruding through the pupil. The patient was hospitalized and treated with local and systemic antibiotics until control of the inflammation was achieved. Corneoscleral transplantation plus excision/transplantation of the corneal limbus were performed, and the entire corneal limbus was lamellarly incised. After completely suturing all around the transplanted corneoscleral graft, the anterior chamber was formed. Postoperative treatment included local antibiotics, anti-inflammatory drugs, and cycloplegic drops. Results: There was no recurrence of infection, and the corneal epithelium gradually regenerated and covered the whole graft. Visual acuity was light perception at 6 months after the surgery. The patient was satisfied that the globe was preserved and did not wish to undergo any further treatment. Conclusions: Corneoscleral transplantation is preferred for the treatment of large-sized descemetoceles with active microbial keratitis and extensive infiltrates, especially in cases where the whole cornea has transformed into a large cyst.
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Ostrovsky, D. S., S. A. Borzenok, B. E. Malyugin, O. P. Antonova, M. Kh Khubetsova, and T. Z. Kerimov. "Preparation and evaluation of a suspension of human corneal endothelial cells isolated from the eyes of cadaveric donors for transplantation in an <em>ex vivo</em> experiment." Russian Journal of Transplantology and Artificial Organs 26, no. 1 (November 21, 2023): 103–12. http://dx.doi.org/10.15825/1995-1191-2024-1-103-112.
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Background. According to the World Health Organization, corneal diseases are one of the major causes of blindness globally. Endothelial dystrophy is one of the etiological factors leading to corneal diseases. The corneal endothelium is a monolayer of cells with virtually no mitotic activity. When the density of corneal endothelial cells falls below a critical threshold, the endothelium loses its ability to regulate corneal stromal hydration. This leads to corneal clouding and, consequently, to reduced visual acuity and quality of life of the patient. In this regard, various keratoplasty methods are widely used in clinical practice. Today, it is technically possible to transplant all corneal layers via penetrating keratoplasty, and to transplant the posterior epithelium via layer-bylayer keratoplasty. These surgical approaches are now widely used in everyday practice, but they require the use of scarce material – cadaveric donor corneas, from which grafts for the above-mentioned operations are formed in the conditions of an eye bank. In this regard, protocols for obtaining human corneal endothelial cell (HCEC) culture for subsequent transplantation have been proposed in recent years. However, the use of such approaches in Russia is limited by the law. The aim of this study was to experimentally justify the possibility of transplanting uncultured endothelial cells, isolated from cadaveric human corneas. Materials and methods. The first stage of the work consisted of obtaining a suspension of endothelial cells from cadaveric donor corneas and studying it; at the second stage, the transplantation effectiveness of the resulting cell suspension was assessed in an ex vivo experiment. Results. The cell phenotype after transplantation by the proposed method had high viability and preservation. Conclusions. The presented results suggest that phenotype and adhesion ability are preserved, and that the cell suspension has a high level of viability under adequate loss of endothelial cells during transplantation in the ex vivo experiment.
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Tarsitano, Martine, Maria Chiara Cristiano, Massimo Fresta, Donatella Paolino, and Concetta Rafaniello. "Alginate-Based Composites for Corneal Regeneration: The Optimization of a Biomaterial to Overcome Its Limits." Gels 8, no. 7 (July 10, 2022): 431. http://dx.doi.org/10.3390/gels8070431.
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For many years, corneal transplantation has been the first-choice treatment for irreversible damage affecting the anterior part of the eye. However, the low number of cornea donors and cases of graft rejection highlighted the need to replace donor corneas with new biomaterials. Tissue engineering plays a fundamental role in achieving this goal through challenging research into a construct that must reflect all the properties of the cornea that are essential to ensure correct vision. In this review, the anatomy and physiology of the cornea are described to point out the main roles of the corneal layers to be compensated and all the requirements expected from the material to be manufactured. Then, a deep investigation of alginate as a suitable alternative to donor tissue was conducted. Thanks to its adaptability, transparency and low immunogenicity, alginate has emerged as a promising candidate for the realization of bioengineered materials for corneal regeneration. Chemical modifications and the blending of alginate with other functional compounds allow the control of its mechanical, degradation and cell-proliferation features, enabling it to go beyond its limits, improving its functionality in the field of corneal tissue engineering and regenerative medicine.
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Musa, Mutali, Marco Zeppieri, Ehimare S. Enaholo, Ekele Chukwuyem, and Carlo Salati. "An Overview of Corneal Transplantation in the Past Decade." Clinics and Practice 13, no. 1 (February 14, 2023): 264–79. http://dx.doi.org/10.3390/clinpract13010024.
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The cornea is a transparent avascular structure located in the front of the eye that refracts light entering the eyes and also serves as a barrier between the outside world and the internal contents of the eye. Like every other body part, the cornea may suffer insult from trauma, infection, and inflammation. In the case of trauma, a prior infection that left a scar, or conditions such as keratoconus that warrant the removal of all or part of the cornea (keratoplasty), it is important to use healthy donor corneal tissues and cells that can replace the damaged cornea. The types of cornea transplant techniques employed currently include: penetrating keratoplasty, endothelial keratoplasty (EK), and artificial cornea transplant. Postoperative failure acutely or after years can result after a cornea transplant and may require a repeat transplant. This minireview briefly examines the various types of corneal transplant methodologies, indications, contraindications, presurgical protocols, sources of cornea transplant material, wound healing after surgery complications, co-morbidities, and the effect of COVID-19 in corneal transplant surgery.
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Pant, Om Prakash, Ji-long Hao, Dan-dan Zhou, and Cheng-wei Lu. "Tectonic keratoplasty using femtosecond laser lenticule in pediatric patients with corneal perforation secondary to blepharokeratoconjunctivitis: a case report and literature review." Journal of International Medical Research 47, no. 5 (April 11, 2019): 2312–20. http://dx.doi.org/10.1177/0300060519841163.
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Blepharokeratoconjunctivitis secondary to ocular demodicosis in the pediatric population is often neglected and may result in a serious sight-threatening condition. In severe cases, it can lead to corneal perforation necessitating urgent corneal transplantation. However, the shortage and high cost of donor corneas is the foremost limitation of keratoplasty in developing countries. Small-incision lenticule extraction is an advanced flapless femtosecond laser refractive procedure in which an intrastromal corneal lenticule is detached and removed to correct myopia and myopic astigmatism. We herein describe a technique in which lenticules are used for the management of corneal perforation secondary to Demodex-induced blepharokeratoconjunctivitis. The lenticule was sutured over the site of the perforated cornea using 10-0 interrupted nylon sutures. The globe integrity was maintained with a good visual outcome. Thus, tectonic keratoplasty using small-incision lenticule extraction appears to be a safe, cost-effective, and reliable alternative method for the management of corneal perforation secondary to blepharokeratoconjunctivitis.
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Borzenok, S. A., B. E. Malyugin, M. Yu Gerasimov, and D. S. Ostrovsky. "Cultivated autologous oral mucosal epithelial transplantation." Russian Journal of Transplantology and Artificial Organs 23, no. 1 (April 10, 2021): 171–77. http://dx.doi.org/10.15825/1995-1191-2021-1-171-177.
Full textAbstract:
According to the World Health Organization, corneal blindness is the fourth most common cause of blindness and visual impairment worldwide. In Russia, up to 18% of blindness is caused by corneal damage. Limbal stem cell deficiency (LSCD) is one of the causes of corneal blindness and visual impairment due to anterior epithelial replacement with fibrovascular pannus. Bilateral LSCD may develop in patients with aniridia, Steven-Jones syndrome, and severe corneal burns of both eyes, leading to severe decrease in visual acuity in both eyes and, as a consequence, physical disability associated with blindness. In such cases, cell therapy, based on autologous oral epithelial culture as an alternative to allogeneic limbus transplants, is proposed for reconstruction of the anterior corneal epithelium. This new treatment method promotes corneal reepithelization, better visual acuity, reduced nonspecific ocular complaints and improved quality of life of patients. The effectiveness and significant increase in the frequency of transparent engraftment of donor corneas after cell therapy drives huge interest in this topic all over the world. This review presents literature data on the features of histotopography and methods for obtaining a cultured autologous oral mucosal epithelium, on cell markers that are used to identify epithelial cells, and on methods for creating cell grafts for subsequent transplantation to the corneal surface in LSCD patients.
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Nam, Ga Hee, Da Ran Kim, Young Chae Yoon, Soon Won Yang, Woong Joo Whang, Yong-Soo Byun, Hyung Bin Hwang, et al. "Development of an Instrument for Slit-lamp Examination of Donor Corneas in Preservation Medium." Journal of the Korean Ophthalmological Society 65, no. 2 (February 15, 2024): 108–16. http://dx.doi.org/10.3341/jkos.2024.65.2.108.
Full textAbstract:
Purpose: To evaluate the effectiveness of an instrument devised for slit-lamp examination of donor corneas suspended in preservation medium.Methods: The study examined two donor corneas received at Yeouido St. Mary's Hospital in February 2023 and March 2023. The instrument has three main components: a plastic holder to hold the preservation medium bottle, a cube with a mirror for reflecting the slit beam, and a stand to attach the device to the slit-lamp. Using the instrument, the donor corneas were examined via slit-lamp: microscopy with the endothelium facing upward and downward. Specular microscopy and anterior segment optical coherence tomography (OCT) were also performed on the preserved donor corneas.Results: Slit-lamp examination of donor corneas in preservation medium using the instrument showed overall corneal buttoning and optical sections of the donor cornea. Using specular reflection and retroillumination, the endothelial layer was partially visible. However, specular microscopy and anterior segment OCT could not examine the donor cornea in preservation medium using the instrument.Conclusions: The devised instrument facilitates slit-lamp examination of donor corneas in preservation medium, enabling a qualitative assessment of donor corneas before corneal transplantation surgery.
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Romano, Vito, Zhuola Zhuola, Zhuo Chang, Bernhard Steger, Hannah J. Levis, Stephen B. Kaye, and Riaz Akhtar. "Biomechanical evaluation of central and peripheral Descemet’s membrane endothelial graft." Modeling and Artificial Intelligence in Ophthalmology 2, no. 2 (June 18, 2018): 47–51. http://dx.doi.org/10.35119/maio.v2i2.71.
Full textAbstract:
Corneal endothelial transplant is the gold-standard treatment in cases of corneal endothelial cellular dysfunction. Preparation, delivery, and unfolding of the graft are technically demanding. We assessed the biomechanical behavior of Descemet’s membrane to better understand Descemet’s membrane endothelial keratoplasty(DMEK) graft behavior, and to select the right diameter and donor age graft . The biomechanical behavior was tested using atomic force microscopy (AFM) on five corneas unsuitable for transplantation. The peripheral cornea was found to be stiffer than the central cornea (3171.89 MPa and 2837.20 MPa, respectively). The elastic modulus of both the central and peripheral cornea exhibited a trend to decrease with age. In addition, the central cornea becomes stiff er than the peripheral cornea in older patients, while the peripheral cornea was stiff er in younger patients. AFM is a suitable technique for evaluating biomechanical behavior of DMEK graft s. One interpretation of this varied behavior is that the type and quantity of collagen changes with age and location.
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Pino, Christopher J., Frederick R. Haselton, and Min S. Chang. "Seeding of Corneal Wounds by Epithelial Cell Transfer from Micropatterned PDMS Contact Lenses." Cell Transplantation 14, no. 8 (September 2005): 565–71. http://dx.doi.org/10.3727/000000005783982783.
Full textAbstract:
Persistent corneal wounds result from numerous eye disorders, and to date, available treatments often fail to accelerate reepithelialization, the key initial step in wound healing. To speed reepithelialization, we explored a cell-transfer transplant method utilizing polydimethylsiloxane (PDMS) contact lenses to deliver epithelial cells derived from limbal explants directly within a corneal wound. Human primary epithelial cells and an immortalized corneal epithelial cell line (HCE-SV40) grew well on PDMS contact lenses and their morphology and growth rates where similar to cells grown on tissue culture polystyrene. To initially study cell transfer from PDMS, HCE-SV40 cells were seeded onto PDMS with or without micropatterned posts. After a day in culture, HCE-SV40 cells attached to the unpatterned PDMS uniformly, whereas on micropatterned PDMS they appeared to attach primarily between posts. The cell-covered PDMS contacts were then placed cell-side down onto tissue culture plastic and, after 1, 2, or 3 days, the PDMS contact was removed and the transferred cells were trypsinized and counted. Micropatterned PDMS contact lenses with 100-μm-diameter posts and a post height of 40 μm transferred three times as many cells as unpatterned PDMS. Cell transfer to a wounded cornea was tested in a pig cornea organ culture model deepithelialized by alkali treatment. Post micropatterned PDMS contact lenses were seeded with labeled HCE-SV40 cells at a density 50,000 cells/cm2 and applied to the wounded pig corneas. After 24, 48, or 96 h of application, PDMS contact lenses were removed, corneas fixed with formaldehyde, and sectioned. After 48 h, epithelial cells transferred from post micropatterned contact lenses to provide 35% epithelial coverage of denuded pig corneas; after 96 h coverage was 65%. We conclude that cell transfer from epithelial-coated PDMS contact lenses micropatterned with posts provides a promising approach to reepithelialize corneal surfaces.
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Han, Sang Beom, Yu-Chi Liu, Karim Mohamed-Noriega, and Jodhbir S. Mehta. "Application of Novel Drugs for Corneal Cell Regeneration." Journal of Ophthalmology 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/1215868.
Full textAbstract:
Corneal transplantation has been the only treatment method for corneal blindness, which is the major cause of reversible blindness. However, despite the advancement of surgical techniques for corneal transplantation, demand for the surgery can never be met due to a global shortage of donor cornea. The development of bioengineering and pharmaceutical technology provided us with novel drugs and biomaterials that can be used for innovative treatment methods for corneal diseases. In this review, the authors will discuss the efficacy and safety of pharmacologic therapies, such as Rho-kinase (ROCK) inhibitors, blood-derived products, growth factors, and regenerating agent on corneal cell regeneration. The promising results of these agents suggest that these can be viable options for corneal reconstruction and visual rehabilitation.
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Sacchetti, Marta, Paolo Rama, Alice Bruscolini, and Alessandro Lambiase. "Limbal Stem Cell Transplantation: Clinical Results, Limits, and Perspectives." Stem Cells International 2018 (October 11, 2018): 1–12. http://dx.doi.org/10.1155/2018/8086269.
Full textAbstract:
Limbal stem cell deficiency (LSCD) is a clinical condition characterized by damage of cornea limbal stem cells, which results in an impairment of corneal epithelium turnover and in an invasion of the cornea by the conjunctival epithelium. In these patients, the conjunctivalization of the cornea is associated with visual impairment and cornea transplantation has poor prognosis for recurrence of the conjunctivalization. Current treatments of LSCD are aimed at replacing the damaged corneal stem cells in order to restore a healthy corneal epithelium. The autotransplantation of limbal tissue from the healthy, fellow eye is effective in unilateral LSCD but leads to depauperation of the stem cell reservoir. In the last decades, novel techniques such as cultivated limbal epithelial transplantation (CLET) have been proposed in order to reduce the damage of the healthy fellow eye. Clinical and experimental evidence showed that CLET is effective in inducing long-term regeneration of a healthy corneal epithelium in patients with LSCD with a success rate of 70%–80%. Current limitations for the treatment of LSCD are represented by the lack of a marker able to unequivocally identify limbal stem cells and the treatment of total, bilateral LSCD which requires other sources of stem cells for ocular surface reconstruction.
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Hussain, Noor Ahmed, Francisco C. Figueiredo, and Che J. Connon. "Use of biomaterials in corneal endothelial repair." Therapeutic Advances in Ophthalmology 13 (January 2021): 251584142110582. http://dx.doi.org/10.1177/25158414211058249.
Full textAbstract:
Human corneal endothelium (HCE) is a single layer of hexagonal cells that lines the posterior surface of the cornea. It forms the barrier that separates the aqueous humor from the rest of the corneal layers (stroma and epithelium layer). This layer plays a fundamental role in maintaining the hydration and transparency of the cornea, which in turn ensures a clear vision. In vivo, human corneal endothelial cells (HCECs) are generally believed to be nonproliferating. In many cases, due to their nonproliferative nature, any damage to these cells can lead to further issues with Descemet’s membrane (DM), stroma and epithelium which may ultimately lead to hazy vision and blindness. Endothelial keratoplasties such as Descemet’s stripping automated endothelial keratoplasty (DSAEK) and Descemet’s membrane endothelial keratoplasty (DEK) are the standard surgeries routinely used to restore vision following endothelial failure. Basically, these two similar surgical techniques involve the replacement of the diseased endothelial layer in the center of the cornea by a healthy layer taken from a donor cornea. Globally, eye banks are facing an increased demand to provide corneas that have suitable features for transplantation. Consequently, it can be stated that there is a significant shortage of corneal grafting tissue; for every 70 corneas required, only 1 is available. Nowadays, eye banks face long waiting lists due to shortage of donors, seriously aggravated when compared with previous years, due to the global COVID-19 pandemic. Thus, there is an urgent need to find alternative and more sustainable sources for treating endothelial diseases, such as utilizing bioengineering to use of biomaterials as a remedy. The current review focuses on the use of biomaterials to repair the corneal endothelium. A range of biomaterials have been considered based on their promising results and outstanding features, including previous studies and their key findings in the context of each biomaterial.
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Jin, He, Liangping Liu, Hui Ding, Miao He, Chi Zhang, and Xingwu Zhong. "Small Incision Femtosecond Laser-assisted X-ray-irradiated Corneal Intrastromal Xenotransplantation in Rhesus Monkeys: A Preliminary Study." Current Molecular Medicine 18, no. 9 (February 18, 2019): 612–21. http://dx.doi.org/10.2174/1566524019666190129123935.
Full textAbstract:
Background: Gamma-ray irradiation could significantly induce widespread apoptosis in corneas and reduced the allogenicity of donor cornea. And the X-rays may have similar biological effects. The feasibility and effects of X-ray-irradiated corneal lamellae have not been assessed yet. Methods: Different doses (10 gray unit (Gy), 20 Gy, 50 Gy, 100 Gy) of X-ray irradiated corneal lamellae were collected from SMILE surgery. These corneal lamellae were assessed by physical characterization, hematoxylin and eosin (H-E) staining, Masson’s staining, TdT-mediated dUTP nick end labeling (TUNEL), cell viability assay and transmission electron microscopy (TEM). We selected the optimum dose (100Gy) to treat the corneal lamellae to be the grafts. The human grafts and fresh allogeneic monkey corneal lamellae were implanted into rhesus monkeys via the small incision femtosecond laser-assisted surgery, respectively. Clinical examinations and the immunostaining were performed after surgery. Results: There were no significant changes in the transparency of the corneal lamellae, but the absorbency of the corneal lamellae was increased. According to the H-E and Masson’s staining results, irradiation had little impact on the corneal collagen. The TUNEL assay and cell viability assay results showed that 100Gy X-ray irradiation resulted in complete apoptosis in the corneal lamellae, which was also confirmed by TEM observations. In the following animal model study, no immune reactions or severe inflammatory responses occurred, and the host corneas maintained transparency for 24 weeks of observation. And the expression of CD4 and CD8 were negative in the all host corneas. Conclusion: X-ray irradiated corneal lamellae could serve as a potential material for xenogeneic inlay, and the small incision femtosecond laser-assisted implantation has the potential to become a new corneal transplantation surgical approach.
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Gimenes, Izabela, Andréa V. Braga Pintor, Mariana da Silva Sardinha, Guido A. Marañón-Vásquez, Marcelo Salabert Gonzalez, Octavio Augusto França Presgrave, Lucianne Cople Maia, and Gutemberg Gomes Alves. "Cold Storage Media versus Optisol-GS in the Preservation of Corneal Quality for Keratoplasty: A Systematic Review." Applied Sciences 12, no. 14 (July 13, 2022): 7079. http://dx.doi.org/10.3390/app12147079.
Full textAbstract:
Optisol-GS is the most widely used pharmaceutical composition to preserve corneas for transplantation. This systematic review investigated the effects of different cold corneal storage media (CCSM) compared with Optisol-GS on the quality of stored corneas. The literature was searched throughout May 2022 on six databases and grey literature. Studies including corneas (population) exposed to distinct cold storage media (exposure) and Optisol-GS (comparison) that reported qualitative and/or quantitative parameters of cornea quality (outcome) were included. Methodological quality was assessed using ToxRTool. From 4520 identified studies, fourteen were included according to the eligibility criteria, comprising 769 evaluated cornea samples comparing Optisol-GS with commercial and noncommercial media. All studies showed good methodological quality. Experimental times ranged from 1–28 days, mainly using 4 °C as the preservation temperature. Viable endothelial cell density (ECD) and endothelial cell morphology (EC) were the most assessed parameters. ECD results for Cornisol were higher than Optisol-GS in 10 days (p = 0.049) and favored Cornea ColdTM up to 4 weeks (p < 0.05), which also showed better qualitative results. While the standardization of test protocols could improve comparisons, evidence indicates that most CCSM present similar performances on cornea preservation for transplantation at seven days, while some formulations may increase preservation at extended times.