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Author: FangJun Bao
Publisher: Frontiers Media SA
ISBN: 2832522572
Category : Science
Languages : en
Pages : 124
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Book Description
Author: FangJun Bao
Publisher: Frontiers Media SA
ISBN: 2832522572
Category : Science
Languages : en
Pages : 124
Get Book Here
Book Description
Author: C.J. Roberts
Publisher: Kugler Publications
ISBN: 9062998763
Category : Medical
Languages : en
Pages : 328
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Book Description
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.
Author: Cynthia J. Roberts
Publisher: Kugler Publications
ISBN: 9062998860
Category : Medical
Languages : en
Pages : 546
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Book Description
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.
Author: Feng Wen
Publisher: Frontiers Media SA
ISBN: 2832501257
Category : Medical
Languages : en
Pages : 373
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Book Description
Author: Taraprasad Das
Publisher: Springer Nature
ISBN: 9819701384
Category :
Languages : en
Pages : 497
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Book Description
Author: Luis Izquierdo
Publisher: Elsevier Health Sciences
ISBN: 0323759793
Category : Medical
Languages : en
Pages : 634
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Book Description
Offering practical clinical guidance for early diagnosis and effective management, Keratoconus: Diagnosis and Management is a concise, easy-to-read guide to help mitigate loss of vision in patients in a way that does not interfere with quality of life. From early diagnosis and intervention through the most up-to-date treatment and surgical approaches, this consolidated reference covers the essential information needed by cornea fellows and specialists, general ophthalmologists, residents, and optometrists. - Provides expert, step-by-step guidance and real-world perspectives from global contributors in the field. - Covers the latest advances in cornea transplantation, corneal collagen cross-linking (CXL) in adult and pediatric patients, intrastromal corneal rings, intraocular lenses, corneal regeneration, and laser surgery. - Includes quick-reference boxes throughout highlighting essential clinical facts, pitfalls, potential complications, and clinical guidelines. - Presents real-world case studies of actual patient scenarios from early to advanced disease states. - Features high-quality imaging for keratoconus at various stages, including OCT, Brillouin scanning microscopy, Scheimpflug and combined Placido and Scheimpflug, combined Placido and AS-OCT, clinical and surgical photos, and more.
Author: Ming Wang
Publisher: CRC Press
ISBN: 1040140408
Category : Medical
Languages : en
Pages : 290
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Book Description
With the rapid advancement of corneal topography and wavefront technologies and the increased application of corneal topography not only in refractive but also in premium IOL surgery, a new edition of the best-selling Corneal Topography: A Guide for Clinical Application in the Wavefront Era will be the foremost resource for both ophthalmologists and optometrists. In this Second Edition, Dr. Ming Wang, Dr. Tracy Swartz and over 50 contributors combine the important topics of refractive and premium lens surgeries and put corneal topography in the context of wavefront technology. With over 500 images, this edition gives special attention to the latest advances in these technologies. The state-of-the-art science and application of corneal topography for these anterior segment surgeries is well represented in Corneal Topography, A Guide for Clinical Application in the Wavefront Era, Second Edition, making it the latest and most comprehensive reference of these state-of-the-art technologies for refractive and for premium IOL surgery. Topographic and Wavefront Technologies Covered Include: • Placido disc-based topographic systems • Elevation-based topographic systems • Ultrasound-based topographic systems • OCT-based topographic systems • Topography and wavefront combined systems Topographic Applications Covered Include: • Topographies of corneal diseases, including post-RK/CK/LASIK/PRK • Topography-guided contact lens fitting • Topography application in refractive surgery and in premium IOL surgeries • Topographic guidance for corneal surgeries • Topography-guided custom treatments • Combined treatment strategies using topography and wavefront data • Future development of corneal topography in the wavefront era Updated and reorganized to reflect changes in the technology, Corneal Topography: A Guide for Clinical Application in the Wavefront Era, Second Edition is indispensible for all anterior segment surgeons, ophthalmologists, and optometrists.
Author: Jorge L. Alió
Publisher: Springer
ISBN: 3319438816
Category : Medical
Languages : en
Pages : 367
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Book Description
As a degenerative disorder of the eye, keratoconus can cause substantial distortion of vision, with multiple images, streaking, and sensitivity to light all reported by patients. Keratoconus: Recent Advances in Diagnosis and Treatment updates ophthalmologists about the innovations that have occurred within the last decade, discussing the diagnostic imaging techniques that have been developed for keratoconus diagnosis, understanding of how examination techniques are related to the evolution of keratoconus, and how to indicate the different therapeutic tools that have been created for keratoconus over the last several years. Additionally, fundamentals for new diagnostic elements, based on the mathematical, physical and biomechanical data are analyzed in depth for a better understanding of the essential diagnostic steps for the clinician to guide patients towards the most adequate therapeutic tool in the case. Modern keratoplasty techniques, assisted by femtosecond lasers or other devices, are also covered and these techniques, along with the emerging conservative treatments, have added to more precise control of the evolution of the disease.
Author: Mohamed H. Doweidar
Publisher: Academic Press
ISBN: 012816610X
Category : Science
Languages : en
Pages : 436
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Book Description
Advances in Biomechanics and Tissue Regeneration covers a wide range of recent development and advances in the fields of biomechanics and tissue regeneration. It includes computational simulation, soft tissues, microfluidics, the cardiovascular system, experimental methods in biomechanics, mechanobiology and tissue regeneration. The state-of-the-art, theories and application are presented, making this book ideal for anyone who is deciding which direction to take their future research in this field. In addition, it is ideal for everyone who is exploring new fields or currently working on an interdisciplinary project in tissue biomechanics. - Combines new trends in biomechanical modelling and tissue regeneration - Offers a broad scope, covering the entire field of tissue biomechanics - Contains perspectives from engineering, medicine and biology, thus giving a holistic view of the field
Author: Robert A. Copeland
Publisher: JP Medical Ltd
ISBN: 9350901722
Category : Medical
Languages : en
Pages : 1666
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Book Description
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
