Download or read book Progressive Keratoconus Insights into Etiopathogenesis Diagnosis and Treatment written by and published by Frontiers Media SA. This book was released on 2023-11-29 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the early stages of keratoconus, visual acuity may be normal and slit-lamp examination is not able to identify the disease phenotype. Early diagnosis of keratoconus is of major importance for effective treatment. That is why corneal topography and tomography has become the gold standard examination for diagnosis of corneal ectasia. Corneal topography is a non-contact imaging tool that gives information about the anterior surface of the cornea. Corneal tomography evaluates both anterior and posterior corneal surfaces and is considered mandatory for preoperatory evaluation before refractive surgery. Until recently, Kmax was the main indicator for the progression of keratoconus, but recent studies showed that posterior elevation represents the first signal of an ectatic corneal disease. Cross-linking is considered the gold standard in the treatment of keratoconus and newer techniques allow this procedure to be selective on the areas of corneal thinning.

Download or read book Refractive Surgery E Book written by Dimitri T. Azar and published by Elsevier Health Sciences. This book was released on 2019-01-09 with total page 563 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive and clinically focused, Refractive Surgery, 3rd Edition, brings you the knowledge and expertise of leading ophthalmology experts and refractive surgeons from around the world. Together they provide practical coverage of the latest advances in this fast-changing field, including improved optics and biomechanics, improved diagnostics, new surgical techniques, and more. Hundreds of high-quality photographs guide you from patient selection to mastery of surgical techniques. - Offers step-by-step guidance on a wide range of common refractive procedures. - Covers new topics such as management of LASIK complications; SMILE and management of SMILE complications; collagen cross-linking, including instrumentation and applications in keratoconus and ectasia; intracorneal lenses; and multifocal and accommodating IOLs. - Contains a new chapter on Preoperative Evaluation of Keratoconus and Ectasia. - Uses high-quality surgical video clips to demonstrate a variety of surgical techniques. - Addresses initial as well as ongoing management of patients. - Includes tables of indications, preferences, hot tips, and management of complications throughout, making guidance quick and easy to access.

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 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 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 Keratoconus E Book written by Luis Izquierdo and published by Elsevier Health Sciences. This book was released on 2022-06-13 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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 Keratoconus written by Sujata Das and published by Springer Nature. This book was released on 2022-10-19 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book covers various aspects of the management of keratoconus, which is a leading cause of visual impairment in young adults. It focuses on the epidemiology and risk factors of keratoconus with a special focus on Southeast Asia. Keratoconus affects the quality of vision, thereby affecting the quality of life. While most patients present with defective vision, many are diagnosed accidentally during screening for refractive surgery. The book covers the varied epidemiology of keratoconus across different parts of the world. It discusses many systemic and ocular diseases associated with keratoconus. The book covers the newer diagnostic techniques and various treatment procedures for keratoconus, helping in diagnosing keratoconus in the early stages and closely watching the progression. It discusses various contact lenses to improve vision quality; widely used collagen crosslinking, and its various modifications for halting the progression. It also explains the surgical approach for keratoconus, such as penetrating keratoplasty, lamellar keratoplasty and other lens-assisted procedures. The book is relevant for general ophthalmologists and cornea specialists.

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 Keratoconus written by Edna Almodin and published by Springer Nature. This book was released on 2022-10-27 with total page 1014 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keratoconus is a progressive disease of the cornea which can lead to blindness as irregular astigmatism increases. The study of the ectasic diseases of the cornea has evolved considerably in the last several years and this has brought new tools for the keratoconus diagnosis and treatment. A better understanding of treatment options can enhance visual rehabilitation and prevent blindness in these patients. This book provides the reader deeply and updated information on keratoconus treatment. Written by experts from worldwide, the book presents clinical, genetic, metabolic and biomechanical aspects in the development of the disease, the proper intervention time, the imaging tests used for diagnosis and keratoconus monitoring, as well as details on new surgical procedures (as contact lenses and laser technologies) using modern methods with wide technological application. Two pioneers in the keratoconus treatment bring their valuable contribution in specific chapters. Ophthalmologists will find a practical and useful approach of new technologies to get the best results for their patients. This book will really impact changes in the therapeutic conduct of corneal surgeons.

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 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 Contact Lens Practice E Book written by Nathan Efron and published by Elsevier Health Sciences. This book was released on 2016-11-27 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thoroughly revised and updated third edition of Contact Lens Practice, award-winning author, researcher and lecturer, Professor Nathan Efron, provides a comprehensive, evidence-based overview of the scientific foundation and clinical applications of contact lens fitting. The text has been refreshed by the inclusion of ten new authors – a mixture of scientists and clinicians, all of whom are at the cutting edge of their specialty. The chapters are highly illustrated in full colour and subject matter is presented in a clear and logical format to allow the reader to quickly hone in the desired information. - Ideal for an optometrist, ophthalmologist, orthoptist, optician, student, or work in the industry, this book will serve as an essential companion and guide to current thinking and practice in the contact lens field. - Highlights of this edition include a new chapter on myopia control contact lenses, as well are completely rewritten chapters, by new authors, on keratoconus, orthokeratology, soft and rigid lens measurement and history taking.

Download or read book Cataract and Refractive Surgery written by Thomas Kohnen and published by Springer Science & Business Media. This book was released on 2006-01-14 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: -Cataract surgery is the most frequently performed surgical intervention worldwide, and the number of refractive surgery procedures, such as LASIK, is growing rapidly -All editors are internationally known experts in the field -Well structured text and design, quick and easy to read -Bridges the gap between primary literature and daily practice, indispensable for continuous education and advanced training -Every 2nd year each volume is updated to include timely information about new developments

Download or read book Osteogenesis Imperfecta written by Javaid Kassim and published by Academic Press. This book was released on 2013-08-06 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Osteogenesis Imperfecta is the first translational reference professionals can turn to for a source of comprehensive information on this disorder. Although several reviews of the field have been published in various journals, there is no other single source for a compendium of current information. Separate chapters discuss each of the several clinical features of OI. Ethical issues related to OI are discussed, as is the importance of nutrition in managing the OI child and the OI adult. The role of physical medicine and rehabilitation for OI patients is also presented, along with the current status of OI medical treatment and the prospects for genetic engineering in the future. The text also provides the orthopedic surgeon with an advanced discussion of surgical techniques applicable to OI. - Incorporates chapters and information on the ethical issues related to osteogenesis imperfecta (OI) as will the importance of nutrition in managing the OI child and the OI adult - Offers new insights into the underlying mechanisms of collagen biochemistry as related to OI as well as a presentation of intracellular collagen processing and the expanded role of protein chaperones in OI - Discusses the role of physical medicine and rehabilitation for OI patients and the current status of OI medical treatment as well as prospects for genetic engineering in the future - Provides a unique overview for the orthopedic surgeon with an advanced discussion of surgical techniques applicable to OI

Download or read book Cornea Handbook written by Bill Trattler and published by SLACK Incorporated. This book was released on 2010 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cornea Handbook is your comprehensive, reference for accessing the fundamentals of corneal conditions, surgeries, and imaging technologies. Incorporating relevant information and color images, with an easy-to-understand style, this handbook is an indispensable resource for all eye care practitioners. Drs. William B. Trattler, Parag A. Majmudar, Jodi I. Luchs, and Tracy S. Swartz have written Cornea Handbook with both the novice and advanced clinician in mind. Packed with essential information on everything from basic anatomy to surgical complications, readers will find this handbook full of valuable knowledge and helpful images. Some topics covered include: * Basic anatomy and physiology * Corneal infection, inflammation, and ocular surface disorders * Metabolic and congenital disorders * Corneal dystrophies and degenerations * Traumatic and chemical injuries * Diagnostic tools with clinical examples * Surgical procedures and common complications Whether you are an ophthalmologist, optometrist, resident, or student, if you are looking for a review of corneal conditions, Cornea Handbook will be a vital addition to your ophthalmic collection and the go-to resource for your everyday use.

Download or read book Contact Lenses written by Anthony J. Phillips and published by Elsevier Health Sciences. This book was released on 2018-11-29 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely revised with the latest advances, evidence, and standards needed for everyday practice, Contact Lenses, 6th Edition, remains a definitive work on this multi-faceted topic, ideal for optometrists, dispensing opticians, ophthalmologists, and contact lens practitioners. This classic, superbly designed text is perfectly suited for health care professionals, providing all of the essential knowledge needed in one convenient volume. - Provides up-to-date, authoritative information on contact lens materials and lens types, treatment in contact lens and tear film complications, and myopia correction and contact lenses for abnormal ocular conditions. - Discusses current topics such as miniscleral lenses, keratoconus, corneal cross linking, and paediatric, cosmetic and prosthetic contact lenses. - Contains high-quality line diagrams and clinical illustrations to highlight key points in the text. - Focuses on the evidence behind contact lens practice, enabling you to make informed choices about the care you give to your patients.