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 Corneal Biomechanics and Refractive Surgery written by Fabio A. Guarnieri and published by Springer. This book was released on 2014-11-27 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a unique approach not found in any other text for those looking to improve the clinical results of refractive surgery by gaining a better understanding of corneal biomechanics and the instrumentation related to it. Written by leading experts in the field, this book provides authoritative coverage of the interactions of the cornea and the bioinstrumentation, such as corneal topography, pachymetry, aberrometers, tonometry and optical coherence tomography. Organized in an easy-to-read manner, Corneal Biomechanics and Refractive Surgery is designed for refractive surgeons and general ophthalmologists alike and describes the biomechanical role of the corneal tissue and how each part is affected in refractive surgery. Additionally, showing what the bioinstrumentation can measure, how models can improve understanding of the interaction between biomechanics, bioinstrumentation, and refractive surgery, and how these models and bioinstrumentation together can improve the refractive results, are also discussed.

Download or read book Copeland and Afshari s Principles and Practice of Cornea written by Robert A. Copeland and published by JP Medical Ltd. This book was released on 2013-02-28 with total page 1666 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cornea is the transparent front part of the eye covering the iris and the pupil, allowing light to enter and covering two thirds of the eye’s focusing tasks. This two volume set is a comprehensive guide to the latest research and techniques for the cornea. Beginning with basic science, examination techniques and epidemiology, the following chapters discuss the diagnosis and the medical and surgical treatment of numerous different conditions and diseases that may affect the cornea. Written by an extensive international editor and author team, this manual features more than 1300 full colour clinical and histopathological images, as well as a DVD demonstrating a multitude of surgical techniques described in the book. Key points Comprehensive two volume set describing diagnosis and treatment of numerous corneal disorders Features more than 1300 colour images and illustrations Includes a DVD demonstrating surgical techniques and procedures Extensive international author and editor team

Download or read book Human Eye Imaging and Modeling written by E. Y. K. Ng and published by CRC Press. This book was released on 2012-06-05 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced image processing and mathematical modeling techniques are increasingly being used for the early diagnosis of eye diseases. A comprehensive review of the field, Human Eye Imaging and Modeling details the latest advances and analytical techniques in ocular imaging and modeling. The first part of the book looks at imaging of the fundus as well as infrared imaging. It begins by exploring developments in the analysis of fundus images, particularly for the diagnosis of diabetic retinopathy and glaucoma. It also reviews anterior segment imaging and reports on developments in ocular thermography, especially the use of thermal imaging as the basis of tear evaporimetry and dry eye diagnosis. The second part of the book delves into mathematical modeling of the human eye. Coverage includes modeling of the eye during retinal laser surgery, a framework for optical simulation, heat distribution using a 3D web-splines solution, and exposure to laser radiation. The text also examines computer simulation of the human eye based on principles of heat transfer, as well as various bioheat equations to predict interior temperatures based on the surface temperature. Featuring contributions by established experts in eye imaging, this is a valuable reference for medical personnel and researchers who want to know more about state-of-the-art computer-based imaging and detection methods. It presents novel imaging and modeling algorithms that can aid in early diagnosis, with the aim of enriching the lives of people suffering from eye abnormalities.

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 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 The Biology of the Eye written by Jorge Fischbarg and published by Elsevier. This book was released on 2005-12-09 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acknowledgement This book is the result of a collective effort. Due to an oversight, mention of three of the contributors who played an especially decisive role in bringing the work to fruition was omitted from the book. They should share fully in the intellectual credits accruing from this publication. I would therefore like to acknowledge and thank the following for their outstanding contributions to editing the work: Dr. Morten Dornonville la Cour (MD, Dr. Med. Sci.) solicited and edited the chapters on retina, RPE, choroid, vitreous, immunology, and sclera. Dr. la Cour is a Lecturer, Eye Department, Copenhagen University Hospital, specializes in vitreoretinal surgery, and frequently lectures in the international scene. A trained mathematician, he has done research in retinal pigment epithelial physiology in the laboratories of Drs. Thomas Zeuthen and Sheldon Miller. Dr. Friedrich P.J. Diecke and Dr. Elliott M. Kanner also provided invaluable editorial assistance. Dr Diecke, who was formerly Professor and Chairman of the Department of Physiology, UMDNJ-New Jersey Medical School, is a Professor Emeritus at that institution. His research has concentrated on membrane transport mechanisms in lens epithelial cells, corneal endothelial cells and peripheral nerve and on the regulation of vascular smooth muscle contraction. Dr. Elliott M. Kanner was born in Canada in 1970. He graduated from Yale University in 1992 with a BS/MS degree in Molecular Biophysics and Biochemistry. He received his PhD degree from the Rockefeller University in 1999 and his MD degree from Weill/Cornell in 2001. He is currently an Ophthalmology resident at Columbia University. Jorge Fischbarg, December 2005 This book explores the many recent novel ideas about the eye in a systematic and synthetic way. It includes both basic sciences and applications towards clinical research. Chapters include both anatomical and functional descriptions of the different ocular tissues and treatments of a few subjects of practical importance for ophthalmologists. This book is intended for students in basic biomedical science interested in the eye, as well as ophthalmologists a comprehensive source on recent developments in ocular research. * Combines basic science and practical opthalmological subjects * Written with the simplicity of a textbook, while maintaining the comprehensive and rigorous approach of science papers * Includes contributions by well-known experts

Download or read book Life Cycle Tribology written by Duncan Dowson and published by Elsevier. This book was released on 2005-10-13 with total page 933 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 31st Leeds-Lyon Symposium on Tribology was held at Trinity and All Saints College in Leeds under the title "Life Cycle Tribology" from Tuesday 7th September until Friday 10th September 2004. Over the three days of presentations that followed, life cycle tribology was explored across a range of areas including automotive tribology, bearings, bio-degradability and sustainability, bio-tribology, coatings, condition monitoring, contact mechanics, debris effects, elastohydrodynamic lubrication, lubricants, machine systems, nanotribology, rolling contact fatigue, transmissions, tribochemistry and wear and failure. Invited talks in these fields were presented by leading international researchers and practitioners, namely C.J. Hooke, J.A. Williams, R.J.K. Wood, G. Isaac, S.C. Tung, D. Price, I. Sherrington, M. Hadfield, K. Kato, R.I. Taylor, H.P. Evans, R.S. Dwyer-Joyce and H. Rahnejat.

Download or read book Ocular Biomechanics in Health and Pathophysiology written by Matthew A. Reilly and published by Frontiers Media SA. This book was released on 2024-06-13 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanical mechanisms may contribute to a large number of visual processes and pathologies, including glaucoma, keratoconus, refractive surgery, accommodation, presbyopia, myopia, hyperopia, trauma, retinal detachment, ocular development, vitreous substitution, cataract surgery, corneal transplant, and many others. Departures from homeostatic loading may drive a large number of these processes in ways we are only beginning to recognize. This Research Topic will explore how ocular biomechanics contribute to both the homeostasis and pathophysiology of the eye and visual system. It is generally unknown whether changes in load drive changes in biomechanical properties or vice versa. Clarifying driving forces for disease and elucidating the pathophysiologic response will ultimately enable the development of targeted treatments for many ocular and visual diseases for which biomechanics plays a role.

Download or read book Doctorates and PhDs written by Aarhus universitet and published by . This book was released on 1999 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Air puff Tonometers written by Robert Koprowski and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book presents the latest achievements and research works of intraocular pressure measurement by the air-puff method presented by experts in the field. It is about tonometers, in particular using the air-puff method. These methods are used, for example, by the Corvis ST. Owing to the ultra-high-speed Scheimpflug camera, which records corneal deformation being the response to an air-puff. In this connection, this book is interdisciplinary in: new methods of image analysis and processing; new engineering methods used in devices; method reducing measurement (intraocular pressure) errors; the change in the blood pulsation phase during measurement affects the results in different ways; other IOP measurement methods (using the air-puff method); medical and engineering problems in air-puff method. This book is recommended reading for those involved in the analysis and processing of images and wanting to expand their knowledge of contemporary diagnostic methods and modern methods of image analysis. Part of IOP Series in Medical and Biological Image Analysis" -- Prové de l'editor.

Download or read book Corneal Cross Linking written by Farhad Hafezi and published by CRC Press. This book was released on 2024-06-01 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corneal Cross-Linking, Second Edition represents an innovative approach to treating primary acquired and secondary induced ectatic disorders. In addition, corneal cross-linking (CXL) has promising applications as an alternative in the treatment of corneal infectious and non-infectious melting, as well as conditions such as Fuchs’ endothelial dystrophy. The new and expanded Second Edition of Corneal Cross-Linking by Drs. Farhad Hafezi and J. Bradley Randleman will provide a concise yet comprehensive summary of the CXL process, including the basic science foundations, treatment protocols and outcomes, recognition and management of potential complications, and modification of standard protocol for special circumstances. Given all the changes in this rapidly progressing field, many brief topics from the first edition have now grown into full chapters or sections. These include expanded sections on alternative treatment protocols, corneal imaging and biomechanics, combing cross-linking with other refractive treatments, and a section devoted specifically to the most highly debated controversies in the field today. With each chapter being fully updated plus including over twenty new chapters that covers the latest advances and future directions, Corneal Cross-Linking, Second Edition represents the cutting-edge of CXL research and clinical practice. “Since the publication of the first edition of this book in 2013, our knowledge of corneal cross-linking has again significantly increased, both scientifically and clinically. Today, concise recommendations (guidelines for cross-linking) help the clinician to select the patients, make decisions, and provide optimal treatment” -Eberhard Spoerl, PhD and Theo Seiler, MD, PhD

Download or read book Biomechanics written by and published by BoD – Books on Demand. This book was released on 2019-01-30 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: I have taught a variety of courses in biomechanics, introductory and advanced, at multiple universities in Canada. I have not been able to find or use an appropriate textbook for students whose background is not biomedical engineering. It should be noted that there are many outstanding books on biomechanics; however, they are usually not very introductory or the topics covered are too detailed, which makes it impossible for those audiences to make effective use of the book. The present book is an attempt to fill this gap. No previous familiarity of anatomy, biology, or physiology is expected, and in fact every chapter begins with a review of the relevant necessary background. Each chapter then highlights identification and explanation of the indispensable aspects of the associated biomechanics issues.

Download or read book Patient Specific Computational Modeling written by Begoña Calvo Lopez and published by Springer Science & Business Media. This book was released on 2012-05-20 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses patient-specific modeling. It integrates computational modeling, experimental procedures, imagine clinical segmentation and mesh generation with the finite element method (FEM) to solve problems in computational biomedicine and bioengineering. Specific areas of interest include cardiovascular problems, ocular and muscular systems and soft tissue modeling. Patient-specific modeling has been the subject of serious research over the last seven years and interest in the area is continually growing and this area is expected to further develop in the near future.

Download or read book Cumulated Index Medicus written by and published by . This book was released on 2000 with total page 1828 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Royal Society Interface written by and published by . This book was released on 2005 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corneal Endothelial Transplant DSEAK DMEK and DLEK written by Thomas John and published by Boydell & Brewer Ltd. This book was released on 2010-09-17 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: A timely, outstanding educational resource dedicated to explaining the new method of performing corneal transplantation without the use of corneal sutures and an absence of full-thickness corneal wound. This comprehensive book includes a discussion of the development of lamellar transplantation; an in-depth discussion of the basic science of corneal structure, physiology, biomechanics and pathology; a primer on advanced corneal imaging; and a review of the surgical techniques and instrumentation required.