Download or read book Clinical and Laboratory Investigation of the Biomechanical Properties of the Cornea written by Tariq Alhamad and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the biomechanical properties of the cornea is important in order to develop and improve new reliable standard procedures which can be used effectively to assess corneal behaviour in any disease condition, or before/after any ocular surgery. We believe that the Ocular Response Analyzer (ORA) is the only device that can measures the biomechanical properties of the cornea in vivo. However, it has been used for the first time both in vivo and in vitro. This thesis presents a clinical and laboratory investigation of the biomechanical properties of the cornea before/after LASIK and corneal cross-linking to improve our understanding of the knowledge required in both the laboratory and the clinic. Different machines were used in this project, including an ORA, an Oculus Pentacam, a spectrophotometer and a UV-X Illumination system. Laser in situ keratomileusis (LASIK) is, at present, one of the most well-known operations used to correct refractive errors; however, ocular problems arising from corneal thinning have been reported in some previous studies. Therefore, I looked at the effects of surgery on the central/peripheral thickness and the anterior/posterior curvature, and determined to what extent they affect the biomechanical properties of the cornea. During the past decade, much research has focused on improving and developing a new operation called corneal collagen cross-linking with riboflavin and UVA, which is used to stop the progression of keratectasia in the cornea (which occurs in keratoconus and sometimes follows refractive surgery). In the next phase, a range of experiments were conducted on cross-linking to determine to what extent this operation affects the molecular structure and biomechanical properties of the cornea. This thesis has shown for the first time that it is possible to obtain ORA signals in vitro and this opened up the possibility of examining whole eyes as well as excised corneas. It is also confirmed that the values of CH do not represent only a corneal biomechanical property, but rather depend on the presence of the rest of the eye. These in vitro studies have opened up a number of possibilities the future corneal biomechanical studies.

Download or read book Corneal Biomechanics written by C.J. Roberts and published by Kugler Publications. This book was released on 2017-05-15 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: While lecturing in recent months at a number of prominent institutions, I asked some of the residents and fellows whether and how they might benefit from a book on corneal biomechanics. The typical response was the look of a deer caught in the headlights as they tried to intuit the “appropriate” answer, but had little understanding or insight as to why this would be an important and useful knowledge base for them now, or in the future. I then posed the question differently. “Would a book that explained corneal biomechanical principles and testing devices and their application in detecting eyes at risk for developing keratoconus and post-LASIK ectasia, understanding the biomechanical impact of specific types of keratorefractive surgery and riboflavin UV-A corneal collagen cross-linking, and the impact of corneal biomechanics on the fidelity of intraocular pressure measurement and risk for glaucoma progression be of interest?” Framed in this context, the answer I got was a resounding, “Yes!” Therein lies a fundamental disconnect that highlights both the opportunity and need to educate all ophthalmologists about this nascent field. This comprehensive book is strengthened by the breadth of contributions from leading experts around the world and provides an important resource for ophthalmologists at all levels of training and experience. It gives a panoramic snapshot of our understanding of corneal biomechanics today, bridging the gap between theoretical principles, testing devices that are commercially available and in development as well as current and potential future clinical applications. While there has been a long-held appreciation that all types of keratorefractive surgery have an impact and interdependence on corneal biomechanics and wound healing, the initial finite element analyses that were applied to understand radial keratotomy were limited by incorrect assumptions that the cornea was a linear, elastic, homogenous, isotropic material.1 With the advent of excimer laser vision correction, critical observations indicated that Munnerlyn’s theoretic ablation profiles did not account for either lower or higher order (e.g. spherical aberration) refractive outcomes,2 suggesting that there were important components missing from the equation—e.g., corneal biomechanics and wound healing. In a seminal editorial, Roberts3 pointed out that the cornea is not a piece of plastic, but rather a material with viscoelastic qualities. Since that time, much has been learned about spatial and depth- related patterns of collagen orientation and interweaving, as well as the biomechanical response to different keratorefractive surgeries that sever tension-bearing lamellae, as the cornea responds to and redistributes stress induced by IOP, hydration, eye rubbing, blinking and extraocular muscle forces.3-6 The first reports of post-LASIK ectasia7 highlighted the need to identify a biomechanical signature of early keratoconus as well as corneas at high risk of developing ectasia irrespective of their current topography or tomography. The introduction of two instruments into clinical use—the Ocular Response Analyzer (ORA) and the Corneal Visualization Scheimpflug Technology (Corvis ST)—that allow measurement of various biomechanical metrics further catapulted the field. The availability of these instruments in routine clinical settings allowed the systematic study of the effect of age, collagen disorders, collagen cross-linking, corneal rings, flaps of various depths, contour, sidecut angulation, pockets, and flockets, just to name of few. Future application of biomechanics to the sclera may improve our understanding of the development and prevention of myopia, as well as scleral surgeries and treatments under development for presbyopia. It was appreciated by Goldmann and Schmidt that corneal thickness and curvature would influence the measurement of applanation tonometry. The recent ability to measure some corneal biomechanical metrics have led to IOP measurement that may be more immune both to their influence and the impact of central corneal thickness (CCT). Certain chapters in this book explain how a thin cornea could be stiffer than a thick one and that stiffness is also impacted by IOP, thereby precluding simplistic attempts to adjust IOP measurements using nomograms based upon CCT alone. Also highlighted is how corneal hysteresis, the ability of the cornea to absorb and dissipate energy during the bidirectional applanation response to a linear Gaussian air puff, appears to be an independent risk factor for glaucoma progression and rate of progression.9,10 This comprehensive book starts out with a section devoted to outlining basic biomechanical principles and theories, teaching us the language of what Dupps11 has referred to as “mechanospeak”, thus providing a context and common vocabulary to better comprehend the following chapters. By first defining basic concepts such as stress-strain relationships and creep, this theoretical basis is later applied to explain the pathogenesis of corneal diseases, e.g., explaining how a focal abnormality in corneal biomechanical properties precipitates a cycle of decompensation and localized thinning and steepening, clinically expressed as ectasia progression. These early chapters further detail biomechanical differences between in-vivo and ex-vivo testing, between human and animal corneas and sclera, and between methods of testing. The second section provides a thorough description of two FDA-approved devices to measure corneal biomechanics in the clinic (i.e., the ORA and the Corvis ST), as well as an overview of potential future technologies, including OCT with air puff stimulus, ocular pulse elastography, and Brilloiun microscopy. The third and final section of the book is a thorough treatise on how to interpret the metrics derived from the waveform provided by available clinical devices; their adjunct use in ectasia risk screening; the comparative biomechanical impact of various keratorefractive surgeries and corneal procedures such as PRK, LASIK, SMILE, and corneal collagen cross-linking; the impact of corneal biomechanics on IOP measurement; and potential biomechanical markers of enhanced susceptibility to glaucoma progression. This compendium of our current knowledge of corneal biomechanics, its measurement and application, provides a strong foundation to more fully understand advances in keratorefractive and corneal surgery, diseases, and treatments, all of which are interdependent on and influence inherent corneal biomechanical properties and behavior. Both the robust aspects and limitations of our current understanding are presented, including the challenge of creating accurate and predictive finite element models that incorporate the impact of IOP, corneal thickness, geometry, and scleral properties on corneal biomechanics. This book provides a key allowing clinical ophthalmologists and researchers to grasp the basics and nuances of this exciting field and to shape it as it evolves in the future.

Download or read book Eye Pathology written by Steffen Heegaard and published by Springer. This book was released on 2014-11-10 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive, in-depth, and up-to-date resource on eye pathology that will be of great practical value for ophthalmic and general pathologists and ophthalmologists. Congenital abnormalities, inflammatory conditions, infections, injuries, degenerative diseases, and tumors are all covered with the aid of more than 700 images. In the case of tumors, the wide variety of neoplasms that occur in the eyelid, conjunctiva, retina, uveal tract, lacrimal gland and sac, orbit, and optic nerve are comprehensively reviewed, and the most recent knowledge on the relation between genetics and prognosis is presented. Entries on specific diseases are organized in a standard way, with information on etiology, epidemiology, clinical presentation, pathological characteristics, differential diagnosis, therapy, and prognosis. The authors are all recognized experts and members of the European and American ophthalmic pathology societies.​

Download or read book Organ Tissue Engineering written by Daniel Eberli and published by Springer. This book was released on 2021-04-22 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The notion of being able to engineer complete organs has inspired an entire generation of researchers. While recent years have brought significant progress in regenerative medicine and tissue engineering, the immense challenges encountered when trying to engineer an entire organ have to be acknowledged. Despite a good understanding of cell phenotypes, cellular niches and cell-to-biomaterial interactions, the formation of tissues composed of multiple cells remains highly challenging. Only a step-by-step approach will allow the future production of a living tissue construct ready for implantation and to augment organ function. In this book, expert authors present the current state of this approach. It offers a concise overview and serves as a great starting point for anyone interested in the application of tissue engineering or regenerative medicine for organ engineering. Each chapter contains a short overview including physiological and pathological changes as well as the current clinical need. The potential cell sources and suitable biomaterials for each organ type are discussed and possibilities to produce organ-like structures are illustrated. The ultimate goal is for the generated small tissues to unfold their full potential in vivo and to serve as a native tissue equivalent. By integrating and evolving, these implants will form functional tissue in-vivo. This book discusses the desired outcome by focusing on well-defined functional readouts. Each chapter addresses the status of clinical translations and closes with the discussion of current bottlenecks and an outlook for the coming years. A successful regenerative medicine approach could solve organ shortage by providing biological substitutes for clinical use - clearly, this merits a collaborative effort.

Download or read book Albert and Jakobiec s Principles and Practice of Ophthalmology written by Daniel M. Albert and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keeping up to date with advances in comprehensive ophthalmology and in the ophthalmic sub-specialties is extremely difficult because of the accelerating rapidity with which new information and technology become available and the diminishing time and opportunity for practitioners and trainees to read and learn. The first edition of Albert and Jakobiec's Principles and Practice (1994) was conceived with the idea of utilizing an electronic, updated version in which the chapters were revised by the chapter authors on an annual or semi-annual basis, but the technology was not sufficiently advanced to achieve this goal. Subsequent editions (2000 and 2008) were organized by Saunders and the last published by Elsevier (of which Springer has obtained the complete rights to move forward with the 4th edition). For nearly three decades, this text has provided its readers with authoritative and comprehensive coverage of clinical ophthalmology, written and edited by a group of authors who represented a "Who's Who" in ophthalmology. By using Springer's Meteor platform, with its ability to allow authors and editors access to updating their chapters online annually/semi-annually, and with the recruitment of select chapter authors, this work's usefulness as the standard text in ophthalmology will be maintained and expanded upon by Springer. The 4th edition of this comprehensive and authoritative text is written by hundreds of the most distinguished authorities from around the world and edited by four leaders in the field, providing today's best answers to every question that arises in ophthalmology practice. Richly illustrated with thousands of high quality, full color, clinically-relevant images, Albert and Jakobiec's Principles and Practice of Ophthalmology, 4th Edition covers every scientific and clinical principle in ophthalmology, ensuring that the reader will always be able to find the guidance needed to diagnose and manage patients' ocular problems and meet today's standards of care. Written for practicing ophthalmologists and trainees, this book delivers in-depth guidance on new diagnostic approaches, operative techniques, and treatment options, as well as coherent explanations of new scientific concept and its clinical importance. The 4th edition will prove to be the source every practicing clinician needs to efficiently and confidently overcome any clinical challenge they may face. Updates include new chapters on anterior and posterior segment diseases, as well as chapters more focused on treatment, plus thousands of new, high-quality, color images and illustrations, updated references, and information on the most cutting-edge technology used by clinicians in their practices today. Additionally, readers will enjoy the same, user-friendly, full-color design they remember from the previous edition, complete with many at-a-glance summary tables, algorithms, boxes, and diagrams that allow the reader to locate the assistance needed more rapidly than ever. .

Download or read book Biomechanics of the Eye written by Cynthia J. Roberts and published by Kugler Publications. This book was released on 2018-04-20 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering all major components of the ocular system, this state-of-the-art text is essential for vision scientists, biomedical engineers, and advanced clinicians with an interest in the role of mechanics in ocular function, disease, therapeutics, and surgery. With every chapter, leading experts strengthen the arguments that biomechanics is an indispensable and rapidly evolving tool for understanding and managing ocular disease.

Download or read book Ocular Rigidity Biomechanics and Hydrodynamics of the Eye written by Ioannis Pallikaris and published by Springer Nature. This book was released on 2021-05-26 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the concept of ocular rigidity, the biomechanical properties and hydrodynamics of the human eye. The basics of anatomy and physiology are explored and the relevant data for the clinician are emphasized throughout the book. The engineering aspects as well as the clinical interpretation are presented to provide context. Ocular Rigidity, Biomechanics and Hydrodynamics of the Eye summarises recent evidence on ocular rigidity, but also provides a complete presentation of the data so far. The authors have recently worked on ocular rigidity corneal and globe biomechanics and hydrodynamics and the new, up-to-date data on the subject are highlighted in each chapter. The aim is to provide the framework or the understanding of these parameters and to determine their relevance in health and disease. This book will be an essential read for all practicing ophthalmologists looking to gain a more in-depth understanding of this interesting area of research particularly in refractive surgery and glaucoma.

Download or read book DSEK written by Francis W. Price and published by SLACK Incorporated. This book was released on 2009 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: "DSEK: What You Need to Know About Endothelial Keratoplasty provides a comprehensive background of EK, where it is today, and where it is headed in the future. Francis W. Price, MD. who was the first to complete DSEK in the United States, along with Marianne Price, PhD, have designed this text to offer a special emphasis on how to perform surgeries along with preventing and managing complications. In addition, a diverse group of contributing authors provides a wide array of insights and tips for better patient outcomes."--BOOK JACKET.

Download or read book Corneal Regeneration written by Jorge L. Alió and published by Springer. This book was released on 2019-02-20 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides expert instruction on the varying surgical techniques currently employed for the regeneration of the ocular surface. Corneal Regeneration: Therapy and Surgery begins with a thorough discussion of current research based on data obtained in clinical human studies, and discusses the potential clinical implications for this promising new stage of eye surgery. Sections devoted to the stem cell, regenerative surgery and therapy of the ocular surface epithelium, corneal stroma, and corneal endothelium follow, each section comprehensively covering applied anatomy, current therapy and regenerative techniques, with a look to future directions of the field including eventual cell therapy. Corneal Regeneration: Therapy and Surgery is the first book of its kind, systematically covering the developments the medical community has achieved in corneal regeneration from all angles. Written and edited by leading experts in the field, researchers and ophthalmologists alike will find this to be a unique source of information on corneal regeneration, as well as a thoughtful reflection on potential applications of regenerative surgery in ophthalmology as a whole.

Download or read book Biomechanical Aspects of Soft Tissues written by Benjamin Loret and published by CRC Press. This book was released on 2017-05-08 with total page 1097 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanics applies the laws and techniques of mechanics in the study of biological systems and related phenomena. Biomechanics uses mathematical and computational tools such as model construction of musclo-skeletal system, body fluid circulation, to aid medical diagnosis, therapeutics and surgery planning, designing of prostheses and implants or in tissue engineering. Present book targets specific topics pertaining to the biomechanics of soft tissues. Subjects addressed includes solids and multi-species mixtures as open systems: a continuum mechanics perspective; electro-chemo-mechanical couplings: tissues with a fixed electric charge and growth of biological tissues.

Download or read book Ehlers Danlos Syndrome A Multidisciplinary Approach written by J.W.G. Jacobs and published by IOS Press. This book was released on 2018-08-14 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Generalized hypermobility has been known since ancient times, and a clinical description of Ehlers-Danlos syndrome (EDS) is said to have first been recorded by Hippocrates in 400 BC. Hypermobility syndromes occur frequently, but the wide spectrum of possible symptoms, coupled with a relative lack of awareness and recognition, are the reason that they are frequently not recognized, or remain undiagnosed. This book is an international, multidisciplinary guide to hypermobility syndromes, and EDS in particular. It aims to create better awareness of hypermobility syndromes among health professionals, including medical specialists, and to be a guide to the management of such syndromes for patients and practitioners. It is intended for use in daily clinical practice rather than as a reference book for research or the latest developments, and has been written to be understandable for any healthcare worker or educated patient without compromise to the scientific content. The book is organized as follows: chapters on classifications and genetics are followed by chapters on individual types, organ (system) manifestations and complications, and finally ethics and therapeutic strategies, with an appendix on surgery and the precautions which should attend it. A special effort has been made to take account of the perspective of the patient; two of the editors have EDS. The book will be of interest to patients with hypermobility syndromes and their families, as well as to all those healthcare practitioners who may encounter such syndromes in the course of their work.

Download or read book Ophthalmology written by Pinakin Davey and published by BoD – Books on Demand. This book was released on 2014-09-03 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together both a review and updates in clinical and research areas. The chapters will be of interest to a wide audience. On one hand, the review and update of clinical practices will interest students and residents, on the other, cutting edge research chapters will be of interest to the researchers in the field. The book is divided into four parts: 1) Review and Updates in Diagnostic Testing, 2) Updates in Anterior Segment Diseases, 3) Updates in Posterior Segment Diseases, and 4) Updates in Research in Ophthalmology, Optometry and Vision Science. The chapters are written by experts and individuals with special interests in topics with a focus on clinical application and translational benefit to eye care.

Download or read book An Introduction to Biomechanics written by Jay D. Humphrey and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designed to meet the needs of undergraduate students, "Introduction to Biomechanics" takes the fresh approach of combining the viewpoints of both a well-respected teacher and a successful student. With an eye toward practicality without loss of depth of instruction, this book seeks to explain the fundamental concepts of biomechanics. With the accompanying web site providing models, sample problems, review questions and more, Introduction to Biomechanics provides students with the full range of instructional material for this complex and dynamic field.

Download or read book Cornea written by Jay H. Krachmer and published by . This book was released on 1997 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive three-volume text covers every aspect of the cornea and external eye: basic science, examination and imaging, eye banking, diagnosis, and medical and surgical management. It is edited by three leaders in corneal disease. Computer enhanced images and artists' drawings supplement the text. Most complete and largest reference published on the cornea. Every aspect of the cornea is covered in this three volume, contributed text: basic science, medical, and surgical, plus practical overviews of eye banking and examination techniques Edited by three nationally renowned corneal specialists who are deemed to be leaders in the ophthalmic community. Computer enhanced illustrations throughout the text. Only reference on the cornea to have a corresponding full-color atlas and slides. Extensive sections on eye banking and corneal manifestations of systemic disease. Extensive up to date reference lists accompany each chapter. Carefully reviewed and tightly edited by the editors

Download or read book Biomechanics written by Y. C. Fung and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: The motivation for writing aseries ofbooks on biomechanics is to bring this rapidly developing subject to students of bioengineering, physiology, and mechanics. In the last decade biomechanics has become a recognized disci pline offered in virtually all universities. Yet there is no adequate textbook for instruction; neither is there a treatise with sufficiently broad coverage. A few books bearing the title of biomechanics are too elementary, others are too specialized. I have long feIt a need for a set of books that will inform students of the physiological and medical applications of biomechanics, and at the same time develop their training in mechanics. We cannot assume that all students come to biomechanics already fully trained in fluid and solid mechanics; their knowledge in these subjects has to be developed as the course proceeds. The scheme adopted in the present series is as follows. First, some basic training in mechanics, to a level about equivalent to the first seven chapters of the author's A First Course in Continuum Mechanics (Prentice-Hall,lnc. 1977), is assumed. We then present some essential parts of biomechanics from the point of view of bioengineering, physiology, and medical applications. In the meantime, mechanics is developed through a sequence of problems and examples. The main text reads like physiology, while the exercises are planned like a mechanics textbook. The instructor may fil1 a dual role: teaching an essential branch of life science, and gradually developing the student's knowledge in mechanics.

Download or read book High Resolution Imaging in Microscopy and Ophthalmology written by Josef F. Bille and published by Springer. This book was released on 2019-08-13 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.

Download or read book Webvision written by Helga Kolb and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: