Viscoelastic department of ophthalmology academic resources. Sep 15, 2007 ocular surgery news viscoelastics, also referred to as ophthalmic viscosurgical devices, or ovds, are viscous substances that allow us to make phacoemulsification easier and safer. Recent advances in ophthalmology 10 top results of your surfing recent advances in ophthalmology 10 start download portable document format pdf and ebooks electronic books free online rating news 20162017 is books that can provide inspiration, insight, knowledge to the reader. This report describes the relevant rheologic properties.
Sodium hyaluronate, the agent with perhaps the widest clinical use, frequently causes marked postoperative iop elevations. It introduces new, selfobtained data regarding viscoelastic rheological properties and describes the selective usages of viscoelastics in ophthalmic surgery. In temperatures above glass transition, components exhibit a more pronounced viscoelastic behavior. Viscoelastic substances in ophthalmology sciencedirect. Among viscoelastic substances, sodium hyaluronate has become the most popular for intraocular surgeries since the introduction of healon sodium. Viscoelastic definition of viscoelastic by medical dictionary. Some examples of these phenomena are discussed in this section1.
Ophthalmic viscosurgical devices ovds, 1 formerly called viscoelastics or viscoelastic substances, are a class of nonactive, clear, gellike chemical compounds with viscous and elastic properties. Viscoelastic substances or pg ophthalmic viscosurgical. Viscoelastics in ophthalmic surgery request pdf researchgate. This book contains a wealth of useful information on current research on viscoelasticity. Eyeworld viscoelastic usage varies with conditions. Individual properties of a viscoelastic substance for ophthalmologic applications are intimately tied to its chemical and rheologic characteristics. Viscoelasticity is the study of materials which have a timedependence. Viscoelastic substances science topic substances that display the physical properties of elasticity and viscosity. The dualnature of these substances causes them to resist applied forces in.
Viscoelastics substances that are highly used in cataract surgery. The lecture note is basically focused on the community as well as clinical ophthalmology to introduce the students on the common causes and burden of blindness and their preventive aspect. Pdf new ophthalmic dualviscoelastic device in cataract surgery. Ophthalmic viscoelastic devices ovds are commonly classified into two.
Division of viscoelastic substances for ophthalmological. Anikavisc viscoelastic gel for cataract ophthalmic surgery. Types of viscoelastics 1 cohesive viscoelastic substances 2 dispersive viscoelastic substances 4. Viscoelastic and suture materials in ophthalmology surgical. A companion chapter, ophthalmic preparationsquality tests 771, will address performance tests such as dissolution and drug release. Among the various viscoelastic substances, sodium hyaluronate. Mar 15, 2017 viscoelastic substances science topic substances that display the physical properties of elasticity and viscosity. Students learn about materials that have viscoelastic behavior along with the importance of engineers. Twentysix different commercially available viscoelastic substances were investigated using the advanced rheometric. Viscoelastic behavior is similarly found in other materials such as wood, polymers, human tissue and solid rocket propellants, to name a few.
Viscoelastic substance an overview sciencedirect topics. Roland polymer physics section naval research laboratory washington, dc isbn 9780199571574. Ophthalmology lecture notes pdf 92p this lecture note will serve as a practical guideline for the hardpressed midlevel health workers. Anikavisc is a highly purified sodium hyaluronate viscoelastic for use in eye surgery including cataract extraction, intraocular lens implantation, corneal transplant surgery, glaucoma filtering surgery, and retina reattachment anikavisc is designed to create and maintain anterior chamber depth and visibility, and to protect corneal endothelial cells and other. Twentysix different commercially available viscoelastic substances were investigated using the advanced rheometric expansion. Use of viscoelastic substance in ophthalmic surgery. Students are introduced to the concept of viscoelasticity and some of the material behaviors of viscoelastic materials, including strain rate dependence, stress relaxation, creep, hysteresis and preconditioning. Viscoelasticity from theory to biological applications. The ciliary sulcus space is then distended with viscoelastic material, and the iol mounted on an injector is placed into the eye. Ophthalmic preparationsquality tests 771 and will include descriptions of and quality tests for all dosage forms that can be applied in the eye.
Topics include systemic antiviral agents and ocular disease. Independent comparative data for vicoelastic substances are not readily available or interpretable. Nov, 2014 introduction substances having dual properties 1. Viscoelastic relaxation modulus characterization using. Viscoelastic definition of viscoelastic by medical. Oxford handbook of ophthalmology 3rd edition pdf free download. Composition examples chemical characteristics chain length molecular wt properties 1. Ocular surgery news viscoelastics, also referred to as ophthalmic viscosurgical devices, or ovds, are viscous substances that allow us to make phacoemulsification easier and safer.
Cataract surgery and intraocular lenses the book covers a wide variety of topics, including monofocal iols, multifocal iols, accommodative iols, injectors and implantation of foldable iols, tear or damage of the iol, and viscoelastic substances. Us4819617a viscoelastic material for ophthalmic surgery. Use of viscoelastic substance in ophthalmic surgeryfocus on sodium hyaluronte. Viscoelastic substances in traumatology and substitution of lacrimal fluid. New ophthalmic dualviscoelastic device in cataract surgery. There are so many books about eye diseases available but hardly any, which are written from the perspective of ethiopia, where more blind are live. For instance, in the unusual cases of adults with white cataracts and in pediatric cataract cases some aspects of viscoelastic usage are critically important, according to kevin m. Request pdf viscoelastics in ophthalmic surgery 1 overview.
Ebook recent advances in ophthalmology 10 as pdf download. Simply injecting a small amount of viscoelastic at the limbus can accomplish this task, and will help prevent the introduction of air bubbles into the anterior chamber. Viscoelastic polymer elasticity physics ophthalmology. The dualnature of these substances causes them to resist applied forces in a. Prior to entering the eye, ensure the viscoelastic flows smoothly from the syringe while also removing all air from the syringe and cannula. Use of viscoelastic substance in ophthalmic surgery focus on sodium hyaluronate. Anikavisc viscoelastic for ophthalmic surgery natural clarity and control anikavisc is a highly purified sodium hyaluronate viscoelastic for use in eye surgery including cataract extraction, intraocular lens implantation, corneal transplant surgery, glaucoma filtering surgery, and retina reattachment. Department of ophthalmology, kanazawa university graduate school of medical science, kanazawa, japan. Many ophthalmic surgeons apply viscoelastic substances in capsulorhexis to achieve a deep anterior chamber and extend the pupillary. Oxford handbook of ophthalmology 3rd edition pdf free. Pdf objective to compare the performance and safety in cataract surgery of two ophthalmic viscoelastic devices. Because of this complex behavior, the use of linear material properties is generally inadequate in accurately determining the final shape of a viscoelastic material, the time taken to arrive at that.
Viscoelastic relaxation modulus characterization using prony. Recent advances in ophthalmology focuses on developments in ophthalmology, including therapy, keratotomy, phototoxicity, and retinopathy. Evaluation of a novel bluecolored ophthalmic viscoelastic device. Ocular viscoelastic devicesovd linkedin slideshare.
Use of viscoelastic substance in ophthalmic surgery focus. Recently, a new development in the field of ophthalmic viscoelastic devices ovds. Crsteurope history of ophthalmic viscosurgical devices. The coordinator will not assign sps to the ophthalmology component until they have completed the vision component. The compilation first offers information on the therapy of herpes simplex, anterior segment surgery, and use of viscous and viscoelastic substances in ophthalmology. We hope that it will be a good introduction to eye diseases for health science students working in ethiopia. Free ophthalmology books download ebooks online textbooks. It has a long history and is still the most widely used model in applications today. Oct 22, 20 recent advances in ophthalmology focuses on developments in ophthalmology, including therapy, keratotomy, phototoxicity, and retinopathy. Viscoelastic and suture materials in ophthalmology free download as powerpoint presentation. This book presents the basic facts of viscoelastic substances. Presentation of viscoelastic materials the most important parameters. By covering a broad variety of rheology, nonnewtonian fluid mechanics and viscoelasticityrelated topics, this book is addressed to a wide spectrum of academic and applied researchers and scientists but it could also prove useful to industry specialists.
Viscoelastic material behavior is compared to elastic solids and viscous fluids. This report describes the relevant rheologic properties e. Viscoelastic materials also help to deal with the concept of creep. The authors detail the broad range of viscoelastic applications, the latest trends in viscosurgery, and describe the complications arising from different surgical techniques with certain viscoelastics. The desirable properties of a viscoelastic substance for ophthalmologic applications are intimately tied to its chemical and rheologic properties. Chemical effects such as inhibition of inflammatory reaction are desirable adjuncts. The goal again is the coating of tissue surfaces and maintaining patency of interspaces and pathways. The cornea is incised and viscoelastic material is injected into the anterior chamber to protect the corneal endothelium. Viscoelastic substances sodium hyaluronate have had a major impact on ophthalmic surgery in the last decade and have become routine in anterior segment surgery. Among viscoelastic substances, sodium hyaluronate has become the most popular for intraocular surgeries since the introduction of healon sodium hyaluronate 1%, 4. The present invention embodies a composition particularly adapted for use as an ophthalmic viscosurgical material for use in the anterior chamber of the eye consisting essentially of an aqueous solution preferably having a near physiological ph and osmolarity and containing at least about 1.
Ophthalmology is a fascinating discipline and you can see the pathology directly. Besides intraocular application, viscoelastic substances can be used on the outer eye. Viscoelastic and suture materials in ophthalmology. Viscoelastic substances or ophthalmic viscosurgical devices ovds compiled by. Information on the production of viscoelastic substances is also included. The compilation first offers information on the therapy of herpes simplex, anterior segment surgery, and. Creep is the tendency of otherwise solid materials to move or to deform with certain stresses or properties.