Download or read book Comparison of Corneal Biomechanical Characteristics After Surface Ablation Refractive Surgery and Novel Lamellar Refractive Surgery written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Current Concepts in Refractive Surgery written by Jeewan S Titiyal and published by Jaypee Brothers Medical Publishers. This book was released on 2021-10-30 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Refractive surgery is eye surgery to improve the refractive state of the eye and reduce or eliminate the need for glasses or contact lenses. The most common type of refractive surgery uses lasers to reshape the curvature of the cornea. This book is a practical guide to the latest advances in refractive surgery procedures. Beginning with an introduction to the evolution of refractive surgery, the next section discusses pre-operative workup, patient evaluation, and decision making. The following sections cover different refractive procedures including corneal ablative, refractive lenticule extraction, lens-based surgeries, enhancements and retreatments, and presbyopia (a condition associated with aging). The final section covers a selection of miscellaneous topics such as bioptics, collagen cross-linking, intracorneal ring segments, incisional surgery, and challenging scenarios. Each section is highly illustrated and provides in depth detail on machines and laser platforms, surgical techniques, outcomes, and potential complications and their management. Key points Practical guide to latest advances in refractive surgery Covers numerous different procedures In depth detail on techniques, outcomes, equipment and complications Highly illustrated with clinical photographs and figures

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 608 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 Current Advances in Ocular Surgery written by Edmund Tsui and published by Springer Nature. This book was released on 2023-07-28 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​The book discusses innovations in surgical techniques and procedures in multiple ophthalmic subspecialties with an evidence based approach.With the rapid development of the field of ophthalmology over the last 10 years, from the development of ever more sophisticated ocular diagnostic technology, to the development of novel medical therapies, ophthalmologists have seen dramatic advancements in the care of their patients.The book highlights various ophthalmic surgical techniques that have been devised, modified, and refined over the last decade, allowing ophthalmic surgeons to achieve surgical perfection. It includes illustrations, clinical photos, videos of surgical procedure. It includes easy to follow salient points in each chapter.This volume of the Current Practices in Ophthalmology book series serves as a valuable resource for post graduate residents in ophthalmology, practicing ophthalmologists, subspecialty fellows, vision science researchers, and general ophthalmologists.

Download or read book The Surgeon s Guide to SMILE written by Dan Reinstein and published by CRC Press. This book was released on 2024-06-01 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corneal refractive surgeons are likely already familiar with the theory behind small incision lenticule extraction (SMILE) and the excellent postoperative outcomes it can achieve, but they were left without a thorough and comprehensive guide to performing the procedure, until now. The Surgeon’s Guide to SMILE: Small Incision Lenticule Extraction is designed to provide surgeons who are interested in starting or are already performing SMILE with a detailed description of the preoperative assessment, surgical technique, and postoperative management of SMILE treatments. This book by Professor Dan Z. Reinstein, Mr. Timothy J. Archer, and Dr. Glenn I. Carp is designed as a surgical video-fellowship, focusing on the granular details of every aspect of patient preparation and management with special attention to how to perform a perfect routine SMILE procedure. The protocols and methods are sourced in both the published scientific evidence and the extensive experience and expertise of the authors. It also includes tips and tricks of how to manage the full range of possible scenarios and complications that can occur during and after a SMILE surgery. Each process described in the book is accompanied by at least one, and in many cases numerous, narrated video examples. Bonus! This dynamic learning tool is supplemented by the SMILE video library containing over 16 hours of surgical videos and tutorials hosted on a companion website. The succinct and demonstrative style of The Surgeon’s Guide to SMILE: Small Incision Lenticule Extraction will help novice and experienced SMILE surgeons alike learn important techniques and improve their outcomes. From the Foreword: “The reader is in for a treat, receiving authoritative technical information from seasoned leaders in the field of refractive surgery, who have attained tremendous experience in excimer laser ablation and who have also been on the forefront of scientific evaluation of the new femtosecond only surgical approach that is SMILE.” -J. Bradley Randleman, MD, University of Southern California, Los Angeles, CA

Download or read book Lamellar Refractive Surgery written by John Charles Casebeer and published by . This book was released on 1996 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, Drs. Casebeer, Ruiz, & Slade go beyond the principles of their own techniques of ALK & LASIK to outline & define the foundation of how these procedures were developed & how they should be performed today. The text closes with a comprehensive look at the ALK & LASIK study results that are available, including the ALK Prospective Trial, the Jeddah ALK Retrospective Review, the Buratto et al Series, the Brint/Slade Summit MKM Report, the Salah et al Pilot Study, the LASIK with Flap Study by Pallikaris & Siganos, & the Bogota LASIK Prospective Study.

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 Corneal Topography written by Melanie Corbett and published by Springer. This book was released on 2019-06-11 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new edition of this leading text atlas on corneal topography has been updated to include the latest advances in technology, such as Pentacam and Orbscan. The principles and theory underlying each technology are first clearly explained, and clinical applications are then examined. The authors describe how to use the different technologies and devices, explain the clinical readout with illustrations of normal corneal topography, discuss applications and findings in common disease states, and present the appearances after various corneal surgical procedures. The pros and cons of each system are highlighted. This up-to-date, superbly illustrated book is the most comprehensive guide to corneal topography currently available. It is anticipated that this second edition will become the seminal corneal topography textbook for all with an interest in corneal disease and its management, and refractive surgery.

Download or read book Ophthalmic Surgery Principles and Practice E Book written by George L. Spaeth and published by Elsevier Health Sciences. This book was released on 2011-09-01 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ophthalmic Surgery, edited by Drs. George Spaeth, Helen Danesh-Meyer, Ivan Goldberg, and Anselm Kampik, provides the detailed, full-color, step-by-step guidance you need to master essential ophthalmic surgery procedures. The international team of expert editors and contributors present coverage of the latest surgical developments and video demonstrations of key techniques across subspecialties, including cataract, cornea, refractive, glaucoma, oculoplastic, extra-ocular muscle, vitreoretinal, and ocular tumor procedures. What’s more, the fully searchable text, procedural videos, and a downloadable image gallery are all online at www.expertconsult.com, making this multimedia resource the key to performing confidently in the operating room. Refer to the most important steps in each procedure quickly and easily with an appendix of step-by-step hand notes. Perform a wide variety of procedures with confidence using the focused coverage that pinpoints essential information and avoids extraneous details. Get comprehensive coverage across key subspecialties—oculoplastic, strabismus, cornea, refractive, cataract, glaucoma, ocular tumors, and vitreoretinal—and master the basics for every common procedure. Access the fully searchable contents online at www.expertconsult.com, along with procedural videos and a downloadable image gallery. Apply the latest advances in laser surgery that have become standard practice with the new section on refractive surgery. Master key techniques thanks to more than four hours of narrated online videos that demonstrate procedures across eight subspecialties. Gain a more nuanced visual understanding through a new full-color art program with over 800 illustrations, updated and revised drawings, color images, and step-by-step illustrated procedures. Tap into the expertise of leading authorities in the field with a brand new editorial team from North America, Europe, and Australasia, as well as international contributors who provide global perspectives across all subspecialties in ophthalmic surgery.

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

Download or read book Corneal Surgery E Book written by Frederick S. Brightbill and published by Elsevier Health Sciences. This book was released on 2008-11-28 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt: This updated, full-color 4th edition features a greatly expanded surgical focus for a practical guide to corneal surgery. The expert guidance of internationally renowned editors provides you with authoritative and current coverage that takes you from an in-depth exploration corneal function as related to corneal surgery through to the correction of refractive errors. New chapters ensure that you stay up-to-date on the latest developments in the field. This easy-to-use, state-of-the-art resource has been reorganized to focus strictly on surgery to provide you with more coverage of recent surgical advances. Presents boxes of clinical pearls throughout the text for accessible expert guidance. Features the latest surgical techniques and postoperative management of penetrating and lamellar keratoplasty —to provide you with details on hot topics in the field. Gives you fresh insights with new sections and a broader perspective from a new team of editors. Makes use of full color throughout the text, as well as step-by-step surgical line illustrations and full-color photographs so you gain a more accurate visual understanding of corneal surgery. Emphasizes refractive surgery considerations, including technique, with supporting medical illustrations and video presentations.

Download or read book Principles and Practice of Ophthalmology E Book written by Daniel M. Albert and published by Elsevier Health Sciences. This book was released on 2008-02-27 with total page 5689 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inside the 3rd edition of this esteemed masterwork, hundreds of the most distinguished authorities from around the world provide today's best answers to every question that arises in your practice. They deliver in-depth guidance on new diagnostic approaches, operative technique, and treatment option, as well as cogent explanations of every new scientific concept and its clinical importance. With its new streamlined, more user-friendly, full-color format, this 3rd edition makes reference much faster, easier, and more versatile. More than ever, it's the source you need to efficiently and confidently overcome any clinical challenge you may face. Comprehensive, authoritative, and richly illustrated coverage of every scientific and clinical principle in ophthalmology ensures that you will always be able to find the guidance you need to diagnose and manage your patients' ocular problems and meet today's standards of care. Updates include completely new sections on "Refractive Surgery" and "Ethics and Professionalism"... an updated and expanded "Geneitcs" section... an updated "Retina" section featuring OCT imaging and new drug therapies for macular degeneration... and many other important new developments that affect your patient care. A streamlined format and a new, more user-friendly full-color design - with many at-a-glance summary tables, algorithms, boxes, diagrams, and thousands of phenomenal color illustrations - allows you to locate the assistance you need more rapidly than ever.

Download or read book Investigation of Corneal Biomechanical and Optical Behaviors by Developing Individualized Finite Element Model written by Mengchen Xu and published by . This book was released on 2019 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The biomechanics of the cornea has a significant impact on its optical behavior. Alterations in corneal biomechanics lead to abnormalities in the surface topography and affect ocular aberrations that degrade retinal image quality. The goal of this thesis work is aimed towards investigating the interaction of corneal biomechanical and optical behaviors through development of an individualized corneal model based on the finite element method that accounts for the large variations in corneal geometry and material properties. The goal of the thesis can be divided into four specific aims. First, we investigated the biomechanical and optical behaviors of a healthy normal cornea at various IOPs through numerical simulations based on a widely accepted anisotropic hyperelastic FE model. We conducted a sensitivity analysis based on a powerful experimental/statistical technique, the DOE method. The biomechanical and optical responses of the cornea to IOP elevation as well as the relative contribution of multiple geometrical and material parameters to corneal biomechanical and optical behaviors were evaluated. We found that the radius of curvature of the cornea was the most important geometric parameter that contributes to both biomechanical and optical behaviors of the cornea. For material parameters, corneal apical displacement was influenced nearly evenly by matrix stiffness, fiber stiffness and nonlinearity. However, the corneal optical aberrations were primarily affected by the matrix stiffness and the distribution of collagen fibril dispersion. These findings have important implications for future theoretical and experimental studies of the cornea, especially for the development of an individualized cornea model. Second, we proposed new methods for material characterization of individual corneas. We aimed to characterize a complete set of material parameters for developing an individualized 3-D anisotropic hyperelastic corneal model, which provides accurate prediction of the interrelation between corneal biomechanics and optics of a specific cornea. We proposed novel methods mainly focusing on the individual quantification of three challenging material parameters, including collagen fiber stiffness, collagen fiber nonlinearity and collagen fibril dispersion using optical information of the cornea to overcome the traditional challenges in corneal material characterization. The new material characterization method could also be beneficial for future development of an in vivo individualized biomechanical model of the cornea and the investigation of the impact of corneal biomechanics on patient's visual performance for clinical applications. Third, we evaluated the clinical significance of corneal biomechanical modeling in one of the important clinical applications, laser refractive surgery. An accurate prediction of the biomechanical response of the cornea to tissue ablation would help to predict postoperative surgical outcomes, which can be taken into account in developing new surgical paradigms for obtaining optimal surgical outcomes. The predictive ability of our biomechanical model was evaluated by simulating myopic corrections in PRK surgery. Our findings suggest that both of the spatial variation in collagen fibril dispersion and the depth-dependent extrafibrillar matrix stiffness play a significant role in the postoperative biomechanical and optical outcomes. Characterization of these two material features helps to predict more accurate trend of the HOAs induced by the surgical process. Lastly, we explored a novel method to induce in vivo IOP elevation for potential future development of an in vivo corneal model. Our new material characterization methods require a measurement of corneal optical behavior at varied IOP levels. Therefore, we investigated the potential of developing an in vivo individualized corneal model for clinical applications by developing an efficient and non-contract method to control IOP elevation in vivo. For the first time, we showed that in vivo IOP can be temporarily elevated and controlled in an innovative, safe, non-contact way using an inversion table. The research presented in this thesis helps to gain understandings of the biomechanical and optical responses of individual corneas to various intraocular pressures and to corneal surgery, such as laser vision correction. Furthermore, the capabilities and techniques described in the thesis may be applied to investigate underlying mechanisms, diagnosis and treatments of other clinically important ophthalmic pathologies such as keratoconus, post-refractive ectasia and glaucoma."--Pages ix-xi.

Download or read book Tools for Improved Refractive Surgery written by Ibrahim Seven and published by . This book was released on 2014 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cornea is the outermost layer of the human eye where the tissue meets with the external environment. It provides the majority of the eye's refractive power and is the most important ocular determinant of visual image formation. The refractive power of the cornea derives from its shape, and this shape is a function of the ocular biomechanical properties and loading forces such as the intraocular pressure (IOP). With having the majority of refractive power in the eye, the cornea is the primary tissue of interest for refractive intervention. Globally, the predominant mode of surgical treatment of refractive disorders is photoablation. However, optical power regression over time and under/over correction due to neglected corneal biomechanical properties were still observed following refractive procedures including LASIK, PRK, Astigmatic, Keratotomy etc., especially at high degree corrections. Also, some evolving procedures such as corneal collagen crosslinking (CXL), a collagen stiffening procedure most commonly performed through UVA photoactivation of riboflavin in the corneal stroma, currently lack surgical guidance for optimizing visual outcomes. Thus, there is a need for methods that explore the patient-specific treatment planning strategies for refractive procedures. This work will have a potential impact in translating mechanical principles into corneal surgical planning in order to provide a better guidance and predictive environment to the corneal surgeons.The goals of this thesis are threefold: 1) To develop patient specific models from clinical LASIK cases and to compare the outcomes of these models with clinical outcomes in a patient population. 2) To simulate investigational procedures that utilize CXL. 3) To advance a potential approach to characterize corneal mechanical properties in vivo.

Download or read book Cornea E Book written by Mark J Mannis and published by Elsevier Health Sciences. This book was released on 2021-03-05 with total page 1976 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only reference available that synthesizes this vast subspecialty into a single trustworthy resource, Cornea, 5th Edition, provides state-of-the-art coverage of the expanding range of contemporary corneal surgery, new diagnostic and imaging technologies, and medical management of corneal and external disease as well as ocular surface disease. Drs. Mark J. Mannis, Edward J. Holland, and a team of more than 200 global experts keep you up to date with both common and more obscure diseases and disorders and the best route to effective treatment and management, making this two-volume text a must-have resource for residents and fellows, general ophthalmologists, and seasoned cornea specialists. Features more than 2,300 exceptionally clear illustrations, diagnostic images, and step-by-step surgical photographs that offer superb visual guidance. Contains 14 new chapters, including Nanothin DSAEK, Aqueous Deficiency Dry Eye Syndrome, Evaluation of Recurrent Corneal Erosions, Evaluation of the Corneal Ulcer, Contemporary Approaches to the Biosynthetic Cornea, and Topography Guided Photorefractive Keratectomy, and more. Includes more than 80 video clips of current corneal surgery techniques, including new clips of the application of cryopreserved amniotic membrane in the treatment of acute stevens , penetrating keratoplasty, DM rupture management in STALK and in the keratonconus patient, and KAMRA corneal inlay implantation. Covers the latest developments in ocular surface transplantation, including new chapters on Conjunctival Limbal Autograft (CLAU); Living Related Conjunctival Limbal Allograft (Lr-CLAL); Keratolimbal Allograft; Cultivated Limbal Epithelial Transplantation; Simple Limbal Epithelial Transplantation; and Outcomes of Ocular Surface Transplantation. Provides key point overviews in each chapter that offer easier access to crucial information.