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 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 Ocular Imaging written by George Asimellis and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Femtosecond Laser Assisted Keratoplasty written by Jorge L Alio and published by JP Medical Ltd. This book was released on 2013-07-30 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keratoplasty is the transplantation of all or part of the cornea to repair scarred or damaged tissue. A femtosecond laser is a laser which emits ultrashort pulses, used for minimally invasive corneal surgery. This book is a concise guide to the technique of femtosecond laser-assisted keratoplasty. Beginning with an introduction to the technology, the following chapters discuss its use for different disorders. This practical text is based on the surgical experience of its internationally recognised authors from Spain, Germany, France and the USA. It includes more than 230 full colour clinical photographs and illustrations to enhance learning. Key points Concise guide to the corneal transplantation procedure of femtosecond laser-assisted keratoplasty Covers key technologies and uses for different disorders Internationally recognised author and editor team Includes more than 230 clinical photographs and illustrations

Download or read book Astigmatism written by Michael Goggin and published by BoD – Books on Demand. This book was released on 2012-02-29 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the development, optics and physiology of astigmatism and places this knowledge in the context of modern management of this aspect of refractive error. It is written by, and aimed at, the astigmatism practitioner to assist in understanding astigmatism and its amelioration by optical and surgical techniques. It also addresses the integration of astigmatism management into the surgical approach to cataract and corneal disease including corneal transplantation.

Download or read book Keratoconus When Why and Why Not A Step by Step Systematic Approach written by Mazen M Sinjab and published by JP Medical Ltd. This book was released on 2012-08-31 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keratoconus is degeneration of the structure of the cornea. The cornea is the clear tissue covering the front of the eye. The shape of the cornea slowly changes from the normal round shape to a cone shape. (PubMed Health). This book is a step by step guide to the diagnosis and treatment of keratoconus. Beginning with an introduction to the classification and patterns of the disease, the following section examines treatment options, discussing in detail when to treat, why to use a particular treatment modality and why not to use other treatment options. Nine case studies are presented, as well as a final self assessment section allowing students to test their knowledge. Key Features Step by step guide to the diagnosis and treatment of keratoconus Clear discussion on which treatments to use and why Nine case studies presented with detailed explanations Includes self assessment section More than 200 colour images and illustrations

Download or read book Mycotic Keratitis written by Mahendra Rai and published by CRC Press. This book was released on 2019-07-23 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mycotic keratitis, also known asfungal keratitis, is commonly defined as an inflammation of the cornea. Globally, mycotic keratitis is more common as compared to others eye disorders. Though it occurs in all parts of the world it is more prevalent in tropical and subtropical areas. Mycotic Keratitis emphasizes novel perspectives on mycotic keratitis treatments and addresses different therapies used in treatment. The book is designed to be immensely useful for the students and teachers of microbiology, medicine, mycology, ophthalmology, biotechnology and nanotechnology. Medical microbiology researchers in general and medical mycology in particular will find it a valuable user-friendly book.

Download or read book Ophthalmic Care written by Janet Marsden and published by M&K Update Ltd. This book was released on 2017-02-16 with total page 907 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by an international team of ophthalmic practitioners, this authoritative book is a vital resource not only for ophthalmic professionals, but for any healthcare professional who cares for patients with eye problems. In the ten years since the first edition was published, practice has moved on, as has the evidence for practice. This second edition draws on the passion and goodwill of the original team of authors, complemented by other colleagues, to fully revise and update the text in line with new findings, new practice and new and exciting treatments. The book is broadly divided into three sections. The first section considers the structure and function of the eye, as well as the basic principles of ophthalmology and eye examination. The second section considers patient care in diverse settings, as well as work-related issues and patient education. It also includes two entirely new chapters on eye banking and global eye health. The third section takes a systematic approach to patient care, working from the front to the back of the eye, discussing some of the common disorders affecting each structure (such as the lens or cornea) or group of structures (such as the eyelids or lacrimal drainage system). The book concludes with a very useful glossary of ophthalmic terms. Some aspects of practice discussed in the text are, of necessity, UK based, but these are clearly indicated and, wherever possible, principles (rather than specifics) are addressed and readers are directed to local policies and interpretations. The first edition of this book became a core text for ophthalmic nursing, in particular, and for the education of ophthalmic nurses across the world. This new edition will provide a comprehensive, up-to-date, evidence-based resource for all ophthalmic healthcare professionals. Contents include: • Physiology of vision • Optics • Pharmacology • Examination of the eye • Visual impairment • Patient education • Work and the eye • Care of the adult ophthalmic patient in an inpatient setting • The care of the child undergoing ophthalmic treatment • Developments in day care surgery for ophthalmic patients • Ophthalmic theatre nursing • The care of patients presenting with acute problems • Eye banking • Global eye health • The eyelids and lacrimal drainage system • The conjunctiva • The cornea • The sclera • The lens • The uveal tract • The angle and aqueous • The retina and vitreous • The orbit and extraocular muscles • Visual and pupillary pathways and neuro-ophthalmology • The eye and systemic disease

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 Management of Complications in Refractive Surgery written by Jorge L. Alio and published by Springer. This book was released on 2018-01-02 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: This illustrated guide is written by international opinion leaders with extensive experience in the practice of refractive surgery. It is the first book devoted to refractive complications (with practical hints and case reports on outcomes) to provide ophthalmic surgeons with the most adequate solutions for the most frequent problems. All complications are described and lavishly illustrated. The book provides ophthalmic surgeons with the most adequate solutions for the most frequent problems they face in their daily practice.

Download or read book Small Incision Lenticule Extraction SMILE written by Walter Sekundo and published by Springer. This book was released on 2015-08-03 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book an international panel of authors offer a clear, step-by-step approach to Small Incision Lenticule Extraction (SMILE), a new refractive procedure approved for the treatment of myopia and astigmatism that is a truly minimally invasive key-hole type surgery. The book opens by discussing important fundamentals of the technology, followed by a close look at the healing response. The current surgical techniques are then described in detail with the aim of providing easy-to-understand guidance for all who wish to perform SMILE surgery or to identify solutions to pitfalls that may arise during the learning curve. Further sections cover the clinical science relating to SMILE (explaining underlying principles), discuss ongoing investigations to further expand the spectrum of SMILE surgery and offer suggestions on how to market the procedure and communicate it to the prospective patient. This guide is “a must” for everyone who wishes to enter the exciting world of SMILE.

Download or read book Controversies in the Management of Keratoconus written by Adel Barbara and published by Springer. This book was released on 2019-02-04 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents new technologies which are available now for the rehabilitation of visual acuity in patients suffering from keratoconusand for arresting the progression of this frustrating disease. All these current treatment options in differing combinations aim to improve the quality of life of the patients and although successful, they are causing confusion for the ophthalmologists; what procedure to do and when? How to perform? Which combination of treatments to choose? Controversies in the Management of Keratoconusprovidesthe widely used treatment options for keratoconus including collagen corneal cross –linking (CXL) covering all the available techniques, intrastromal corneal ring segments (ICRS) , phakic intra-ocular lenses (IOLs), photorefractive keratectomy (PRK) combined or not with CXL penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty ( DALK). Each treatment is addressed by more than one author with different points of view in order to present the various approaches, the logic behind them and the most relevant clinical data available.A chapter by the editor tries to put some light on how to navigate among these controversies. This book will be of interest to trainees as well as the specialized ophthalmologists.

Download or read book Keratoconus written by Ashraf Armia and published by Springer Nature. This book was released on 2021-11-20 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a practical guide to the most recent advances in the diagnostic management of corneal ectasia. Clear, concise chapters address new standardized nomograms of treatment of early progressive ectasia, new epithelium on future crosslinking with and without oxygen supplement, customized protocols, laser assisted corneal regularization protocols and the new femtolaser assisted lamellar corneal transplant. Clinicians and surgeons seeking a go-to guide on the topic of corneal ectasia will find this book to be an essential resource for the latest developments and predicted future trends in the field.

Download or read book Excimer Laser Refractive Surgery written by Jeffery J. Machat and published by Thorofare, NJ : Slack. This book was released on 1996 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides comprehensive information on the approved excimer laser. Aimed at ophthalmologists who want to completely understand the fundamentals of PRK and LASIK, the two procedures are fully defined, along with the background of the laser and the development of current technology.

Download or read book Contemporary Scleral Lenses Theory and Application written by Melissa Barnett and published by Bentham Science Publishers. This book was released on 2017-11-03 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary Scleral Lenses: Theory and Application, provides comprehensive information about scleral lenses. Chapters of this volume have been contributed by renowned scleral lens experts and cover a variety of interesting topics. These topics include the history and evolution of scleral lenses, basic scleral lens structure, optics and customizable features of scleral lenses, analysis of ocular surface shape, ocular surface topography and advances in optometry technology. These topics give readers an explanation of how to utilize diagnostic equipment in optometry practice and enables practitioners to employ a scientific and objective approach to scleral lens fitting. Key features of this volume include: - A straightforward approach to ophthalmic examination flow, evaluation and documentation - A review of Scleral lens care and handling - Descriptions of a variety of complex medical and ocular indications for scleral lenses - Strategic tips to promote your own scleral lens practice - A unique perspective of esteemed corneal specialists regarding the collaborative care of the patient This textbook is a suitable reference for ophthalmology students and practitioners. This text will assist practitioners in enhancing their scleral lens practice by providing them useful information for improving patient vision, ocular surface rehabilitation and quality of life.

Download or read book Corneal Collagen Cross Linking written by Mazen M. Sinjab and published by Springer. This book was released on 2016-11-09 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides comprehensive coverage of corneal collagen cross-linking (CXL), a major management modality for keratoconus and ectatic corneal disorders. All aspects are covered, including refractive and non-refractive surgery indications, models of application, safety, efficacy, performance, outcome measures, evidence of CXL, complications, contraindications, use in children, and controversies. The discussion reflects the considerable progress that has been made in understanding of the modality since its development in the late 1990s. Detailed attention is paid to new concepts, changing surgical techniques and indications, the latest evidence-based science and research, and the future of CXL. Guidance is also provided on the use of CXL in combination with other modalities, such as LASIK, PRK, intracorneal ring implantation and others. The text is accompanied by numerous high-quality color illustrations. Corneal Collagen Cross Linking will provide the reader with a sound grasp of the technique and its use and will hopefully also serve as a stimulus to further research and advances.

Download or read book A Practical Guide to Clinical Application of OCT in Ophthalmology written by Michele Lanza and published by BoD – Books on Demand. This book was released on 2019-10-02 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: I am very proud and excited to introduce to you this book, which provides many interesting indications on how to better understand and handle the world of opticalcoherence tomography (OCT). Reading the chapters, you will be aware that this device is extremely important not just in the clinical practice of retinal diseases, but is also very useful as a surgical tool. Moreover, application of OCT has crossed the borders of the retina and is currently being applied to corneal diseases and glaucoma. I amconfident you will find enough useful information to improve your practice using OCT and to provide a better quality of care for your patients.