The Human Eye: Structure and Function
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MR Imaging of the Orbital Apex
J Korean Radiol Soc 2000;4 :26 9-0 6 1 6 MR Imaging of the Orbital Apex: An a to m y and Pat h o l o g y 1 Ho Kyu Lee, M.D., Chang Jin Kim, M.D.2, Hyosook Ahn, M.D.3, Ji Hoon Shin, M.D., Choong Gon Choi, M.D., Dae Chul Suh, M.D. The apex of the orbit is basically formed by the optic canal, the superior orbital fis- su r e , and their contents. Space-occupying lesions in this area can result in clinical d- eficits caused by compression of the optic nerve or extraocular muscles. Even vas c u l a r changes in the cavernous sinus can produce a direct mass effect and affect the orbit ap e x. When pathologic changes in this region is suspected, contrast-enhanced MR imaging with fat saturation is very useful. According to the anatomic regions from which the lesions arise, they can be classi- fied as belonging to one of five groups; lesions of the optic nerve-sheath complex, of the conal and intraconal spaces, of the extraconal space and bony orbit, of the cav- ernous sinus or diffuse. The characteristic MR findings of various orbital lesions will be described in this paper. Index words : Orbit, diseases Orbit, MR The apex of the orbit is a complex region which con- tains many nerves, vessels, soft tissues, and bony struc- Anatomy of the orbital apex tures such as the superior orbital fissure and the optic canal (1-3), and is likely to be involved in various dis- The orbital apex region consists of the optic nerve- eases (3). -
Symptoms of Age Related Macular Degeneration
WHAT IS MACULAR DEGENERATION? wavy or crooked, visual distortions, doorway and the choroid are interrupted causing waste or street signs seem bowed, or objects may deposits to form. Lacking proper nutrients, the light- Age related macular degeneration (AMD) is appear smaller or farther away than they sensitive cells of the macula become damaged. a disease that may either suddenly or gradually should, decrease in or loss of central vision, and The damaged cells can no longer send normal destroy the macula’s ability to maintain sharp, a central blurry spot. signals from the macula through the optic nerve to central vision. Interestingly, one’s peripheral or DRY: Progression with dry AMD is typically slower your brain, and consequently your vision becomes side vision remains unaffected. AMD is the leading de-gradation of central vision: need for increasingly blurred cause of “legal blindness” in the United States for bright illumination for reading or near work, diffi culty In either form of AMD, your vision may remain fi ne persons over 65 years of age. AMD is present in adapting to low levels of illumination, worsening blur in one eye up to several years even while the other approximately 10 percent of the population over of printed words, decreased intensity or brightness of eye’s vision has degraded. Most patients don’t the age of 52 and in up to 33 percent of individuals colors, diffi culty recognizing faces, gradual increase realize that one eye’s vision has been severely older than 75. The macula allows alone gives us the in the haziness of overall vision, and a profound drop reduced because your brain compensates the bad ability to have: sharp vision, clear vision, color vision, in your central vision acuity. -
CHQ-GDL-01074 Acute Management of Open Globe Injuries
Acute management of Open Globe Injuries Document ID CHQ-GDL-01074 Version no. 2.0 Approval date 14/05/2020 Executive sponsor Executive Director Medical Services Effective date 14/05/2020 Author/custodian Director Infection Management and Prevention service, Review date 14/05/2022 Immunology and Rheumatology Supersedes 1.0 Applicable to All Children’s Health Queensland (CHQ) staff Authorisation Executive Director Clinical Services (QCH) Purpose This evidence-based guideline provides clinical practice advice for clinicians for the acute management of children with open globe injuries. A paediatric ophthalmology team must be actively involved in the management of all patients presenting with this condition. Scope This guideline applies to all Children’s Health Queensland (CHQ) Staff treating a child presenting for the management of open globe injury. Related documents • CHQ-GDL-01202 CHQ Paediatric Antibiocard: Empirical Antibiotic Guidelines • CHQ-PROC-01035 Antimicrobial Restrictions • CHQ Antimicrobial Restriction list • CHQ-GDL-01023 Tetanus Prophylaxis in Wound Management CHQ-GDL-01074- Acute management of Open Globe Injuries - 1 - Guideline Introduction Ocular trauma is an important cause of eye morbidity and is a leading cause of non-congenital mono-ocular blindness among children.1 A quarter of a million children present each year with serious ocular trauma. The vast majority of these are preventable.2 Open globe injuries are injuries where the cornea and/or sclera are breached and there is a full-thickness wound of the eye wall.3 It can be further delineated into globe rupture from blunt trauma and lacerations from sharp objects. When a large blunt object impacts onto the eye, there is an instant increase in intraocular pressure and the eye wall yields at its weakest point leading to tissue prolapse.4 Open globe lacerations are caused by sharp objects or projectiles and subdivided into either penetrating or perforating injuries. -
How Clean Is Your Capsule?
Eye (1989) 3, 678-684 How Clean is Your Capsule? W. T. GREEN and D. L. BOASE Portsmouth Summary Proliferation of residual lens epithelial cells is believed to be the major cause of pos terior capsule opacification following extracapsular cataract extraction. During sur gery these cells can be visualised with appropriate illumination facilitating their mechanical removal with the McIntyre cannula. When flat preparations of the anterior capsule are examined by light microscopy, the areas 'cleaned' of cells in this way appear transparent but scanning electron microscopy reveals tufts of remaining debris which may represent points of cellular attachment to the capsule. Control of lens epithelial cell proliferation is important for the future development of cataract surgery. The undoubted advantages of extracapsular and also on human cadaver eyes. A horizontal cataract extraction are offset in many patients capsulotomy in the upper part of the lens by posterior capsule opacification requiring allowed nucleus removal. Irrigation and caps ulotomy. Not only is this disappointing aspiration of the cortical lens material was for the patient, but the procedure carries a then carried out using a McIntyre cannula risk of serious complications. with Hartman's irrigation solution. During in The major cause of posterior capsule opac vitro surgery this was aided by first removing ification is proliferation of residual lens epi the entire cornea and iris to improve visual thelial cells. I If these cells could be removed at isation and explore different methods of the time of surgery we believe that the inci illumination. dence of posterior capsule opacification and The importance of illumination was first the need for subsequent capsulotomy would suspected when it was observed, during rou be reduced. -
The Distribution of Immune Cells in the Uveal Tract of the Normal Eye
THE DISTRIBUTION OF IMMUNE CELLS IN THE UVEAL TRACT OF THE NORMAL EYE PAUL G. McMENAMIN Perth, Western Australia SUMMARY function of these cells in the normal iris, ciliary body Inflammatory and immune-mediated diseases of the and choroid. The role of such cell types in ocular eye are not purely the consequence of infiltrating inflammation, which will be discussed by other inflammatory cells but may be initiated or propagated authors in this issue, is not the major focus of this by immune cells which are resident or trafficking review; however, a few issues will be briefly through the normal eye. The uveal tract in particular considered where appropriate. is the major site of many such cells, including resident tissue macro phages, dendritic cells and mast cells. This MACRO PHAGES review considers the distribution and location of these and other cells in the iris, ciliary body and choroid in Mononuclear phagocytes arise from bone marrow the normal eye. The uveal tract contains rich networks precursors and after a brief journey in the blood as of both resident macrophages and MHe class 11+ monocytes immigrate into tissues to become macro dendritic cells. The latter appear strategically located to phages. In their mature form they are widely act as sentinels for capturing and sampling blood-borne distributed throughout the body. Macrophages are and intraocular antigens. Large numbers of mast cells professional phagocytes and play a pivotal role as are present in the choroid of most species but are effector cells in cell-mediated immunity and inflam virtually absent from the anterior uvea in many mation.1 In addition, due to their active secretion of a laboratory animals; however, the human iris does range of important biologically active molecules such contain mast cells. -
Ciliary Zonule Sclera (Suspensory Choroid Ligament)
ACTIVITIES Complete Diagrams PNS 18 and 19 Complete PNS 23 Worksheet 3 #1 only Complete PNS 24 Practice Quiz THE SPECIAL SENSES Introduction Vision RECEPTORS Structures designed to respond to stimuli Variable complexity GENERAL PROPERTIES OF RECEPTORS Transducers Receptor potential Generator potential GENERAL PROPERTIES OF RECEPTORS Stimulus causing receptor potentials Generator potential in afferent neuron Nerve impulse SENSATION AND PERCEPTION Stimulatory input Conscious level = perception Awareness = sensation GENERAL PROPERTIES OF RECEPTORS Information conveyed by receptors . Modality . Location . Intensity . Duration ADAPTATION Reduction in rate of impulse transmission when stimulus is prolonged CLASSIFICATION OF RECEPTORS Stimulus Modality . Chemoreceptors . Thermoreceptors . Nociceptors . Mechanoreceptors . Photoreceptors CLASSIFICATION OF RECEPTORS Origin of stimuli . Exteroceptors . Interoceptors . Proprioceptors SPECIAL SENSES Vision Hearing Olfaction Gustation VISION INTRODUCTION 70% of all sensory receptors are in the eye Nearly half of the cerebral cortex is involved in processing visual information Optic nerve is one of body’s largest nerve tracts VISION INTRODUCTION The eye is a photoreceptor organ Refraction Conversion (transduction) of light into AP’s Information is interpreted in cerebral cortex Eyebrow Eyelid Eyelashes Site where conjunctiva merges with cornea Palpebral fissure Lateral commissure Eyelid Medial commissure (a) Surface anatomy of the right eye Figure 15.1a Orbicularis oculi muscle -
Microscopic Anatomy of the Eye Dog Cat Horse Rabbit Monkey Richard R Dubielzig Mammalian Globes Mammalian Phylogeny General Anatomy Dog
Microscopic Anatomy of the eye Dog Cat Horse Rabbit Monkey Richard R Dubielzig Mammalian globes Mammalian Phylogeny General Anatomy Dog Arterial Blood Vessels of the Orbit General Anatomy Dog * Horizontal section Long Posterior Ciliary a. Blood enters the globe Short Post. Ciliary a Long Post. Ciliary a. Anterior Ciliary a. Blood Supply General Anatomy Dog Major arterial circle of the iris Orbital Anatomy Dog Brain Levator Dorsal rectus Ventral rectus Zygomatic Lymph node Orbital Anatomy Dog Orbital Anatomy Dog Cartilaginous trochlea and the tendon of the dorsal oblique m. Orbital Anatomy Dog Rabbit Orbital Anatomy Dog Zygomatic salivary gland mucinous gland Orbital Anatomy Dog Gland of the Third Eyelid Eye lids (dog) Eye lids (dog) Meibomian glands at the lid margin Holocrine secretion Eye lids (primate) Upper tarsal plate Lower tarsal plate Eye lids (rabbit) The Globe The Globe Dog Cat Orangutan Diurnal Horse Diurnal Cornea Epithelium Stromal lamellae Bowman’s layer Dolphin Descemet’s m Endothelium TEM of surface epithelium Cornea Doubling of Descemet’s Vimentin + endothelium Iris Walls: The vertebrate eye Iris Sphincter m. Dilator m Blue-eye, GFAP stain Iris Collagen Iris Cat Sphinctor m. Dilator m. Iris Cat Phyomelanocytes Iris Equine Corpora nigra (Granula iridica) seen in ungulates living without shade Ciliary body Pars plicata Ciliary muscle Pars plana Ciliary body Zonular ligaments Ciliary body Primarily made of fibrillin A major component of elastin Ciliary body Alcian Blue staining acid mucopolysaccharides: Hyaluronic acid Ciliary -
Action and Perception Are Temporally Coupled by a Common Mechanism That Leads to a Timing Misperception
The Journal of Neuroscience, January 28, 2015 • 35(4):1493–1504 • 1493 Behavioral/Cognitive Action and Perception Are Temporally Coupled by a Common Mechanism That Leads to a Timing Misperception Elena Pretegiani,1,2 Corina Astefanoaei,3 XPierre M. Daye,1,4 Edmond J. FitzGibbon,1 Dorina-Emilia Creanga,3 Alessandra Rufa,2 and XLance M. Optican1 1Laboratory of Sensorimotor Research, NEI, NIH, DHHS, Bethesda, Maryland, 20892-4435, 2EVA-Laboratory, University of Siena, 53100 Siena, Italy, 3Alexandru Ioan Cuza University, Physics Faculty, 700506 Iasi, Romania, and 4Institut du cerveau et de la moelle´pinie e `re (ICM), INSERM UMRS 975, 75013 Paris, France We move our eyes to explore the world, but visual areas determining where to look next (action) are different from those determining what we are seeing (perception). Whether, or how, action and perception are temporally coordinated is not known. The preparation time course of an action (e.g., a saccade) has been widely studied with the gap/overlap paradigm with temporal asynchronies (TA) between peripheral target onset and fixation point offset (gap, synchronous, or overlap). However, whether the subjects perceive the gap or overlap, and when they perceive it, has not been studied. We adapted the gap/overlap paradigm to study the temporal coupling of action and perception. Human subjects made saccades to targets with different TAs with respect to fixation point offset and reported whether they perceived the stimuli as separated by a gap or overlapped in time. Both saccadic and perceptual report reaction times changed in the same way as a function of TA. The TA dependencies of the time change for action and perception were very similar, suggesting a common neural substrate. -
The Complexity and Origins of the Human Eye: a Brief Study on the Anatomy, Physiology, and Origin of the Eye
Running Head: THE COMPLEX HUMAN EYE 1 The Complexity and Origins of the Human Eye: A Brief Study on the Anatomy, Physiology, and Origin of the Eye Evan Sebastian A Senior Thesis submitted in partial fulfillment of the requirements for graduation in the Honors Program Liberty University Spring 2010 THE COMPLEX HUMAN EYE 2 Acceptance of Senior Honors Thesis This Senior Honors Thesis is accepted in partial fulfillment of the requirements for graduation from the Honors Program of Liberty University. ______________________________ David A. Titcomb, PT, DPT Thesis Chair ______________________________ David DeWitt, Ph.D. Committee Member ______________________________ Garth McGibbon, M.S. Committee Member ______________________________ Marilyn Gadomski, Ph.D. Assistant Honors Director ______________________________ Date THE COMPLEX HUMAN EYE 3 Abstract The human eye has been the cause of much controversy in regards to its complexity and how the human eye came to be. Through following and discussing the anatomical and physiological functions of the eye, a better understanding of the argument of origins can be seen. The anatomy of the human eye and its many functions are clearly seen, through its complexity. When observing the intricacy of vision and all of the different aspects and connections, it does seem that the human eye is a miracle, no matter its origins. Major biological functions and processes occurring in the retina show the intensity of the eye’s intricacy. After viewing the eye and reviewing its anatomical and physiological domain, arguments regarding its origins are more clearly seen and understood. Evolutionary theory, in terms of Darwin’s thoughts, theorized fossilization of animals, computer simulations of eye evolution, and new research on supposed prior genes occurring in lower life forms leading to human life. -
The Proteomes of the Human Eye, a Highly Compartmentalized Organ
Proteomics 17, 1–2, 2017, 1600340 DOI 10.1002/pmic.201600340 (1 of 3) 1600340 The proteomes of the human eye, a highly compartmentalized organ Gilbert S. Omenn Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA Proteomics has now published a series of Dataset Briefs on the EyeOme from the HUPO Received: November 2, 2016 Human Proteome Project with high-quality analyses of the proteomes of these compartments Accepted: November 4, 2016 of the human eye: retina, iris, ciliary body, retinal pigment epithelium/choroid, retrobulbar optic nerve, and sclera, with 3436, 2929, 2867, 2755, 2711, and 1945 proteins, respectively. These proteomics resources represent a useful starting point for a broad range of research aimed at developing preventive and therapeutic interventions for the various causes of blindness. Keywords: Biomedicine / Biology and Disease-driven Human Proteome Project / End Blindness by 2020 / Eye proteome / EyeOme / Human Proteome Project See accompanying articles in the EyeOme series: http://dx.doi.org/10.1002/pmic.201600229; http://dx.doi.org/10.1002/pmic.201500188; http://dx.doi.org/10.1002/pmic.201400397 Proteomics has now published a series of four papers on compartments of the eye as shown in Fig. 1. As was noted [5], the human eye proteome [1–4]. Under the aegis of the Hu- it was not feasible to assess the quality of the data or estimate man Proteome Organization Biology and Disease-driven Hu- numbers of likely false positives in the heterogeneous studies man Proteome Project (HPP), the EyeOme was organized by from which these findings were summarized. -
Eyelid Conjunctival Tumors
EYELID &CONJUNCTIVAL TUMORS PHOTOGRAPHIC ATLAS Dr. Olivier Galatoire Dr. Christine Levy-Gabriel Dr. Mathieu Zmuda EYELID & CONJUNCTIVAL TUMORS 4 EYELID & CONJUNCTIVAL TUMORS Dear readers, All rights of translation, adaptation, or reproduction by any means are reserved in all countries. The reproduction or representation, in whole or in part and by any means, of any of the pages published in the present book without the prior written consent of the publisher, is prohibited and illegal and would constitute an infringement. Only reproductions strictly reserved for the private use of the copier and not intended for collective use, and short analyses and quotations justified by the illustrative or scientific nature of the work in which they are incorporated, are authorized (Law of March 11, 1957 art. 40 and 41 and Criminal Code art. 425). EYELID & CONJUNCTIVAL TUMORS EYELID & CONJUNCTIVAL TUMORS 5 6 EYELID & CONJUNCTIVAL TUMORS Foreword Dr. Serge Morax I am honored to introduce this Photographic Atlas of palpebral and conjunctival tumors,which is the culmination of the close collaboration between Drs. Olivier Galatoire and Mathieu Zmuda of the A. de Rothschild Ophthalmological Foundation and Dr. Christine Levy-Gabriel of the Curie Institute. The subject is now of unquestionable importance and evidently of great interest to Ophthalmologists, whether they are orbital- palpebral specialists or not. Indeed, errors or delays in the diagnosis of tumor pathologies are relatively common and the consequences can be serious in the case of malignant tumors, especially carcinomas. Swift diagnosis and anatomopathological confirmation will lead to a treatment, discussed in multidisciplinary team meetings, ranging from surgery to radiotherapy. -
Lid and Lash Conditions
Perth Veterinary Ophthalmology Lid and Lash Conditions Eyelid Diseases The most common eyelid diseases are entropion, ectropion and facial droop. Entropion Entropion means a turning in of the lids. This is a common complaint in young dogs but can sometimes affect older dogs and cats as well. Most cases in young dogs affect the lower lids, but the upper lid can become affected in later life in some breeds such as Cocker Spaniels and Bloodhounds. Entropion Some breeds such as Shar Peis, Chows, Rottweillers and Mastiffs can have very complex entropion leading to defects in both upper and lower lids. A Shar Pei with severe upper and lower lid entropion Entropion is painful and can be potentially blinding. The rolling in of the lid leads to hair coming into contact with the cornea, leading to pain, ulceration and scarring (which can affect vision). In severe cases this can even lead to perforation of the eye. There are many causes of entropion. It can be primary or secondary to other problems affecting the lids (such as ectopic cilia, distichiasis etc. - see below). Some possible causes include the lid being too long, the lid being too tight, instability of the lateral canthus (outer cornea of the eyelids), misdirection of the lateral canthal tendon, brachycephalic anatomy (big eyes and short nose - e.g. Pekingese, Pugs, Shih Tsus, Persian cats etc.), diamond eye defects, loose or too much skin, facial droop etc. Often these cases are referred to a veterinary ophthalmologist for proper assessment and treatment to provide the best outcome. Entropion requires surgical correction.