The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Norbert Pfeiffer - One of the best experts on this subject based on the ideXlab platform.
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irregularity of the posterior corneal surface after curved interface femtosecond laser assisted versus microkeratome assisted descemet stripping automated endothelial keratoplasty
Cornea, 2013Co-Authors: Jan M Vetter, Christina Butsch, Melissa Faust, Irene Schmidtmann, Esther M Hoffmann, Walter Sekundo, Norbert PfeifferAbstract:Purpose:During donor Tissue Preparation for Descemet stripping automated endothelial keratoplasty (DSAEK), either microkeratome or femtosecond laser can be used for intrastromal cutting. We compared morphological and functional outcomes after DSAEK using both cutting techniques.Methods:In this retro
Stavros G Demos - One of the best experts on this subject based on the ideXlab platform.
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Adaptation of microscopy with ultraviolet surface excitation for enhancing STEM and undergraduate education
Journal of biomedical optics, 2018Co-Authors: Chi Z. R. Huang, Ronald W. Wood, Stavros G DemosAbstract:Microscopy with ultraviolet surface excitation (MUSE) is investigated as a means to enhance curricula and education in the life sciences based on simplicity of use, the incorporation of inexpensive hardware, and the simplest methods of Tissue Preparation. Ultraviolet excitation in effect replaces Tissue sectioning because it penetrates only a few micrometers below the Tissue surface at the single cell level, preventing the generation of out-of-focus light. Although Tissue autofluorescence may be used, image quality and content can be enhanced by a brief immersion in a solution of nontoxic fluorescent dyes that selectively highlight different cellular compartments. Safe mixed-dye powder combinations have been developed to provide students who have minimal lab proficiencies with a one-step Tissue staining process for rapid Tissue Preparation.
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translating ultraviolet autofluorescence microscopy toward clinical endomicroscopy
Proceedings of SPIE, 2011Co-Authors: Bevin Lin, Stavros G Demos, Shiro Urayama, Ramez M G Saroufeem, Dennis L MatthewsAbstract:The potential of autofluorescence microscopy under ultraviolet excitation is investigated as a method to visualize superficial epithelial microstructures and their modification with progression of disease. This method does not require the use of contrast agents, sectioning methods, or Tissue Preparation. Imaging of esophagus Tissue is the focus of this study and deals with three main issues: a) What is the origin of the signal; b) How the gradual microstructure modification associated with various stages of esophageal disease is visualized; c) What are the designing parameters for in vivo implementation.
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visualization of epithelial morphology using autofluorescence microscopy under ultraviolet excitation
Bios, 2010Co-Authors: Bevin Lin, Stavros G Demos, Dennis L Matthews, M Shiro D Urayama, M Ramez G M D SaroufeemAbstract:Epithelial microstructures related to early stage carcinoma are currently invisible to traditional white light endoscopy. We recently demonstrated that autofluorescence microscopy under ultraviolet excitation can visualize superficial microstructures without the use of contrast agents, sectioning methods, or Tissue Preparation. Spectroscopic analysis allowed a better understanding of autofluorescence signal characteristics at the microscopic level and the mechanism for achieving high quality imaging of the superficial epithelial layer with conventional wide-field microscopy. The designing parameters for the adaptation of this technology into an endoscope probe for real-time in vivo microscopy are tested using a bench-top prototype system. This approach may provide a powerful tool for the detection and staging of carcinomas.
Maria A Woodward - One of the best experts on this subject based on the ideXlab platform.
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corneal donor Tissue Preparation for descemet s membrane endothelial keratoplasty
Journal of Visualized Experiments, 2014Co-Authors: Hassan Tausif, Lauren Johnson, Michael S Titus, Kyle Mavin, Navasuja Chandrasekaran, Maria A Woodward, Roni M Shtein, Shahzad I MianAbstract:Descemet’s Membrane Endothelial Keratoplasty (DMEK) is a form of corneal transplantation in which only a single cell layer, the corneal endothelium, along with its basement membrane (Descemet's membrane) is introduced onto the recipient's posterior stroma3. Unlike Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK), where additional donor stroma is introduced, no unnatural stroma-to-stroma interface is created. As a result, the natural anatomy of the cornea is preserved as much as possible allowing for improved recovery time and visual acuity4. Endothelial Keratoplasty (EK) is the procedure of choice for treatment of endothelial dysfunction. The advantages of EK include rapid recovery of vision, preservation of ocular integrity and minimal refractive change due to use of a small, peripheral incision1. DSAEK utilizes donor Tissue prepared with partial thickness stroma and endothelium. The rapid success and utilization of this procedure can be attributed to availability of eye-bank prepared precut Tissue. The benefits of eye-bank Preparation of donor Tissue include elimination of need for specialized equipment in the operating room and availability of back up donor Tissue in case of Tissue perforation during Preparation. In addition, high volume Preparation of donor Tissue by eye-bank technicians may provide improved quality of donor Tissue. DSAEK may have limited best corrected visual acuity due to creation of a stromal interface between the donor and recipient cornea. Elimination of this interface with transplantation of only donor Descemet's membrane and endothelium in DMEK may improve visual outcomes and reduce complications after EK5. Similar to DSAEK, long term success and acceptance of DMEK is dependent on ease of availability of precut, eye-bank prepared donor Tissue. Here we present a stepwise approach to donor Tissue Preparation which may reduce some barriers eye-banks face in providing DMEK grafts.
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eye bank Preparation of endothelial Tissue
Current Opinion in Ophthalmology, 2014Co-Authors: Grace E Boynton, Maria A WoodwardAbstract:Purpose of reviewEye-bank Preparation of endothelial Tissue for keratoplasty continues to evolve. Although eye-bank personnel have become comfortable and competent at Descemet's stripping automated endothelial keratoplasty (DSAEK), Tissue Preparation and Tissue transport, optimization of Preparation
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corneal donor Tissue Preparation for endothelial keratoplasty
Journal of Visualized Experiments, 2012Co-Authors: Maria A Woodward, Michael S Titus, Kyle Mavin, Roni M ShteinAbstract:Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes 1,2 . Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection 3-6 . Initially, cornea donor posterior lamellar dissection for DSEK was performed manually 1 resulting in variable graft thickness and damage to the delicate corneal endothelial Tissue during Tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin Tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in Tissue processing. Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal Tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar Tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference in terms of the quality of the Tissue 7 or patient outcomes 8,9 using eye bank precut Tissue versus surgeon-prepared Tissue for DSAEK surgery. For most corneal surgeons, the availability of precut DSAEK corneal Tissue saves time and money 10 , and reduces the stress of performing the donor corneal dissection in the operating room. In part because of the ability of the eye banks to provide high quality posterior lamellar corneal in a timely manner, DSAEK has become the standard of care for surgical management of corneal endothelial disease.
George B Mcdonald - One of the best experts on this subject based on the ideXlab platform.
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histopathologic diagnosis of chronic graft versus host disease national institutes of health consensus development project on criteria for clinical trials in chronic graft versus host disease ii pathology working group report
Biology of Blood and Marrow Transplantation, 2006Co-Authors: Howard M Shulman, David E Kleiner, Thomas H Morton, Steven Z Pavletic, Evan R Farmer, Margaret J Moresi, Joel K Greenson, Anne Janin, Paul J Martin, George B McdonaldAbstract:This consensus document provides an update for pathologists and clinicians about the interpretation of biopsy results and use of this information in the management of hematopoietic cell transplantation patients. Optimal sampling and Tissue Preparation are discussed. Minimal criteria for the diagnosis of graft-versus-host disease (GVHD) are proposed, together with specific requirements for the diagnosis of chronic GVHD. Four final diagnostic categories (no GVHD, possible GVHD, consistent with GVHD, and definite GVHD) reflect the integration of histopathology with clinical, laboratory, and radiographic information. Finally, the Working Group developed a set of worksheets to facilitate communication of clinical information to the interpreting pathologist and to aid in clinicopathologic correlation studies. Forms are available at http://www.asbmt.org/cGvHD_Guidelines. The recommendations of the Working Group represent a consensus opinion supplemented by evaluation of available peer-reviewed literature. Consensus recommendations and suggested data-capture forms should be validated in prospective clinicopathologic studies. © 2006 American Society for Blood and Marrow Transplantation
Gerrit R J Melles - One of the best experts on this subject based on the ideXlab platform.
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standardized no touch donor Tissue Preparation for dalk and dmek harvesting undamaged anterior and posterior transplants from the same donor cornea
Acta Ophthalmologica, 2013Co-Authors: Esther Groeneveldvan A Beek, Jessica T Lie, Jacqueline Van Der Wees, Marieke Bruinsma, Gerrit R J MellesAbstract:. Purpose: To describe a standardized ‘no-touch’ harvesting technique of anterior and Descemet membrane (DM) grafts for use in deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK), which provides undamaged anterior and posterior corneal grafts. Methods: A retrospective evaluation was performed of our standard method for harvesting DM grafts and DALK grafts (Technique I; n = 31) versus a newly designed ‘no-touch’ technique (Technique II; n = 31), in which a peripheral ring of trabecular meshwork Tissue is left in-situ, and the DM graft is trephined on an underlying soft contact lens. Endothelial cell density (ECD) before and immediately after DM stripping was used as the main outcome parameter. Results: Endothelial cell density did not differ within Techniques I and II (before versus after DM stripping) (p = 0.75 and p = 0.54, respectively) or among Techniques I and II (p = 0.61). With the latter technique, anterior corneal grafts and posterior DM grafts could be harvested with negligible damage to the endothelial cell layer or the posterior stromal bed. All 93 grafts (62 DM grafts) were eligible for transplantation, and six months post-operatively all transplants used were functional. Conclusion: The new technique offers the following advantages: (i) production of ‘undamaged’ grafts for DALK and DMEK, (ii) better controlled Tissue handling of the thin DM graft during DM stripping and (iii) an increase in availability of corneal grafts obtained from the same donor Tissue pool.
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donor Tissue Preparation for descemet membrane endothelial keratoplasty
Journal of Cataract and Refractive Surgery, 2008Co-Authors: Jessica T Lie, Renuka S Birbal, Lisanne Ham, Jacqueline Van Der Wees, Gerrit R J MellesAbstract:Purpose To evaluate a technique for preparing a donor Descemet membrane carrying autologous endothelium for transplantation in Descemet membrane endothelial keratoplasty (DMEK). Setting Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands. Methods A 9.5 mm diameter DM carrying autologous endothelium was stripped from 10 corneoscleral rims that had been organ cultured for 1 week. The endothelial cell density (ECD) was evaluated with light microscopy before and immediately after DM was stripped and during 4 additional weeks of organ culture. Results The mean ECD was 2701 cells/mm2 ± 302 (SD) before and 2719 ± 322 cells/mm2 immediately after DM was stripped and declined from 2604 ± 352 cells/mm2 after 1 week to 2190 ± 768 cells/mm2 after an additional 4 weeks of organ culture (n = 10). Typical “endothelial streaks,” ie, linear cellular disruptions observed immediately after DM was stripped, showed complete regeneration after the second culture period. Conclusions Descemet grafts for transplantation in DMEK procedures can be surgically prepared from organ-cultured corneal rims and stored for an additional 3 weeks with acceptable endothelial cell loss. Because the donor Tissue can be dissected directly from organ-cultured corneoscleral rims, donor Preparation for DMEK can be readily accessible to most corneal surgeons.
