An Evidence-Based Approach To Abnormal Vision

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    An Evidence-Based Approach

    To Abnormal VisionIt is late in the evening, and the ED is packed. You head towards your next patientwho is in her gurney in the hallway; shes a pleasant, elderly female with all thesweetness of the perfect grandmother.

    So, what brings you here today? She smiles sheepishly. Well, Doctorearlier this evening I suddenly noticed that I kept bumping into my furniture.Thats really it.

    You have a long conversation with her, and she has absolutely no other symp-toms, except she comments that the run-ins with her furniture were more frequenton her right side than on her left. She has normal pupils, visual acuity, fun-doscopy, extraocular eye movements, facial and tongue movements, motorstrength, sensation, coordination, balance, reflexes, and gait. Heart, lungs,

    abdomen, extremities, faceeverything is normal.Nothing tells you that you are dealing with anything other than a normal

    grandmother, until you think of one last exam element to check

    An acute onset of abnormal vision is distressing to the patientand a challenge to the emergency physician. The problem canresult from any component in the visual process, from light trans-

    mission through the cornea to cortical perception and fixation. It is

    important for the emergency physician to rapidly determine the

    nature of the abnormality, localize the cause, administer interven-

    tions that are required emergently, and then to arrange either an

    immediate or deferred evaluation by the appropriate specialist, ifneeded. This issue of Emergency Medicine Practice concentrates on

    the symptom-based development of a differential diagnosis for an

    acute non-traumatic visual disturbance and the management of

    various etiologies prioritized by those that require time-critical

    interventions.

    September 2007Volume 9, Number 9

    Author

    Kama Guluma, MDAssociate Clinical Professor, Department ofEmergency Medicine, UCSD Medical Center, SanDiego, CA

    Peer Reviewers

    Adhi N. SharmaAssistant Professor, Department of EmergencyMedicine, Mount Sinai, School of MedicineChairman; Department of Emergency Medicine,Good, Samaritan Hospital Medical Center WestIslip, New York, NY

    Andy Jagoda, MD, FACEPProfessor and Vice-Chair of Academic Affairs,Department of Emergency Medicine, Mount Sinai

    School of Medicine; Medical Director, Mount SinaiHospital, New York, NY

    CME Objectives

    Upon completion of this article, you should be able to:1. Understand the various manifestations of visual

    disturbances.2. Establish a focused differential diagnosis for an

    acute visual disturbance based on symptoms,involvement of one or both eyes, and the pres-

    ence or absence of pain.3. Determine the most likely etiologies of an abnor-

    mal ocular examination finding.

    4. Distinguish those etiologies of a visual distur-bance that require emergent intervention fromthose that do not.

    5. Evaluate various neuro-ophthalmological causesof abnormal vision using a rational strategy.

    6. Appreciate the degree of evidence behind treat-ment strategies for various causes of visual dis-turbance.

    Date of original release: September 1, 2007Date of most recent review: August 2, 2007

    Termination date: September 1, 2010

    Time to complete activity: 4 hours

    See Physician CME Information on back page.

    Editor-in-Chief

    Andy Jagoda, MD, FACEP

    Professor and Vice-Chair of Academic

    Affairs, Department of Emergency

    Medicine; Mount Sinai School of

    Medicine; Medical Director, Mount Sinai

    Hospital, New York, NY

    Associate Editor

    John M. Howell, MD, FACEP

    Clinical Professor of Emergency

    Medicine, George Washington

    University, Washington, DC; Dir. of

    Academic Affairs, Best Practices, Inc,

    Inova Fairfax Hospital, Falls Church, VA

    Editorial Board

    William J. Brady, MD

    Associate Professor and Vice Chair,

    Department of Emergency Medicine,

    University of Virginia, Charlottesville, VA

    Peter DeBlieux, MD

    Professor of Clinical Medicine, LSU

    Health Science Center, New Orleans,

    LA

    Wyatt W. Decker, MD

    Chair and Associate Professor of

    Emergency Medicine, Mayo Clinic

    College of Medicine, Rochester, MN

    Francis M. Fesmire, MD, FACEP

    Director, Heart-Stroke Center,

    Erlanger Medical Center; AssistantProfessor, UT College of Medicine,

    Chattanooga, TN

    Michael J. Gerardi, MD, FAAP, FACEP

    Director, Pediatric Emergency

    Medicine, Childrens Medical Center,

    Atlantic Health System; Department of

    Emergency Medicine, Morristown

    Memorial Hospital, NJ

    Michael A. Gibbs, MD, FACEP

    Chief, Department of Emergency

    Medicine, Maine Medical Center,

    Portland, ME

    Steven A. Godwin, MD, FACEP

    Assistant Professor and EmergencyMedicine Residency Director,University of FloridaHSC/Jacksonville, FL

    Gregory L. Henry, MD, FACEP

    CEO, Medical Practice Risk

    Assessment, Inc; Clinical Professor of

    Emergency Medicine, University of

    Michigan, Ann Arbor

    Keith A. Marill, MD

    Instructor, Department of EmergencyMedicine, Massachusetts General

    Hospital, Harvard Medical School;

    Boston, MA

    Charles V. Pollack, Jr, MA, MD, FACEP

    Professor and Chair, Department of

    Emergency Medicine, Pennsylvania

    Hospital, University of Pennsylvania

    Health System, Philadelphia, PA

    Michael S. Radeos, MD, MPH

    Assistant Professor of Emergency

    Medicine, Lincoln Health Center,

    Bronx, NY

    Robert L. Rogers, MD, FAAEM

    Assistant Professor and Residency

    Director, Combined EM/IM Program,

    University of Maryland, Baltimore, MD

    Alfred Sacchetti, MD, FACEP

    Assistant Clinical Professor,

    Department of Emergency Medicine,

    Thomas Jefferson University,

    Philadelphia, PA

    Corey M. Slovis, MD, FACP, FACEP

    Professor and Chair, Department of

    Emergency Medicine, Vanderbilt

    University Medical Center, Nashville,TN

    Jenny Walker, MD, MPH, MSW

    Assistant Professor; Division Chief,

    Family Medicine, Department of

    Community and Preventive Medicine,

    Mount Sinai Medical Center, New

    York, NY

    Ron M. Walls, MD

    Professor and Chair, Department of

    Emergency Medicine, Brigham &

    Womens Hospital, Boston, MA

    Research Editors

    Nicholas Genes, MD, PhD

    Mount Sinai Emergency Medicine

    Residency.

    Beth Wicklund, MD

    Regions Hospital Emergency

    Medicine Residency, EMRA

    Representative

    International Editors

    Valerio Gai, MD

    Senior Editor, Professor and Chair,

    Dept of EM, University of Turin, ItalyPeter Cameron, MD

    Chair, Emergency Medicine, Monash

    University; Alfred Hospital, Melbourne,

    Australia

    Amin Antoine Kazzi, MD, FAAEM

    Associate Professor and Vice Chair,

    Department of Emergency Medicine,

    University of California, Irvine;

    American University, Beirut, Lebanon

    Hugo Peralta, MD

    Chair of Emergency

    Services, Hospital Italiano, Buenos

    Aires, Argentina

    Maarten Simons, MD, PhD

    Emergency Medicine Residency

    Director, OLVG Hospital, Amsterdam,

    The Netherlands

    Faculty Disclosure: Dr. Guluma, Dr. Sharma, and Dr. Jagoda report no significant financial interest or other relationship with themanufacturer(s) of any commercial product(s) discussed in this educational presentation.

    Commercial Support: Emergency Medicine Practicedoes not accept any commercial support.

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    Critical Appraisal Of The Literature

    The literature regarding the management of chronic

    eye processes such as open angle glaucoma, macular

    degeneration, amblyopia, cataracts, and diabetic

    retinopathy is rich with large, prospective, random-

    ized, controlled trials and practice guidelines. On

    the other hand, the literature regarding the diagnos-

    tic and therapeutic issues in addressing acute visualdisturbances, especially emergency conditions pre-

    senting to the ED, is limited and primarily character-

    ized by observational case series and small trials. In

    some instances, the only evidence are either case

    reports or expert opinion.

    Anatomy, Epidemiology, And Pathophysiology

    The etiology and pathophysiology of abnormal

    vision is best described by using the anatomic frame-

    work of the visual pathway. The process of visual

    perception starts as light reflected off ambient objects

    is refracted as it is transmitted through the cornea

    and lens and travels through the vitreous to impact

    the retina, see Figure 1. Light paths cross prior to

    reaching the retina, and, therefore, objects in the tem-

    poral field of vision are detected on the nasal portion

    of the retina, while those in the nasal field of vision

    are detected on the temporal portion of the retina.

    The central macula is the area of most acute vision.

    Photoreceptors in the retina generate electrical

    impulses which travel centrally through the optic

    nerve and then decussate at the optic chiasm such

    that information from one side of the visual field is

    conducted in the contralateral side of the post-chias-

    mic neural tracts. The impulses travel backwards

    through each optic tract to the lateral geniculate bod-

    ies, and travel from there via the optic radiations to

    the visual cortex in the ipsilateral occipital lobe.

    Impulses also leave the lateral gen