Visual Loss of Uncertain Origin: Diagnostic Strategies
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Masqueraders of Age-Related Macular Degeneration
COVER STORY Masqueraders of Age-related Macular Degeneration A number of inherited retinal diseases phenocopy AMD. BY RONY GELMAN, MD, MS; AND STEPHEN H. TSANG, MD, PHD ge-related macular degeneration (AMD) is a leading cause of central visual loss among the elderly population in the developed world. The Currently, there are no published A non-neovascular form is characterized by mac- guidelines to prognosticate ular drusen and other abnormalities of the retinal pigment epithelium (RPE) such as geographic atrophy (GA) and Stargardt macular degeneration. hyperpigmented areas in the macula. The neovascular form is heralded by choroidal neovascularization (CNV), with subsequent development of disciform scarring. ABCA4 defect heterozygote carrier may be as high as This article reviews the pathologic and diagnostic char- one in 20.11,12 An estimated 600 disease-causing muta- acteristics of inherited diseases that may masquerade as tions in the ABCA4 gene exist, of which the three most AMD. The review is organized by the following patterns common mutations account for less than 10% of the of inheritance: autosomal recessive (Stargardt disease and disease phenotypes.13 cone dystrophy); autosomal dominant (cone dystrophy, The underlying pathology of disease in STGD involves adult vitelliform dystrophy, pattern dystrophy, North accumulation of lipofuscin in the RPE through a process Carolina macular dystrophy, Doyne honeycomb dystro- of disc shedding and phagocytosis.14,15 Lipofuscin is toxic phy, and Sorsby macular dystrophy); X-linked (X-linked to the RPE; furthermore, A2E, a component of lipofuscin, retinoschisis); and mitochondrial (maternally inherited causes inhibition of 11-cis retinal regeneration16 and diabetes and deafness). complement activation. -
Move Your Wheelchair with Your Eyes
International Journal of Applied Mathematics, Advanced Technology and Science Electronics and Computers ISSN:2147-82282147-6799 www.atscience.org/IJAMEC Original Research Paper Move Your Wheelchair with Your Eyes Gökçen ÇETİNEL*1, Sevda GÜL2, Zafer TİRYAKİ3, Enes KUZU4, Meltem MİLLİGÜNEY5 Accepted : 12/05/2017 Published: 21/08/2017 DOI: 10.18100/ijamec.2017Special Issue30462 Abstract: In the proposed study, our goal is to move paralyzed people with their eyes. Otherwise, use this document as an instruction set. Paper titles should be written in uppercase and lowercase letters, not all uppercase. For this purpose, we use their Electrooculogram (EOG) signals obtained from EOG goggles completely designed by the authors. Through designed EOG goggles, vertical-horizontal eye movements and voluntary blink detection are verified by using 5 Ag-AgCl electrodes located around the eyes. EOG signals utilized to control wheelchair motion by applying signal processing techniques. The main steps of signal processing phase are pre-processing, maximum-minimum value detection and classification, respectively. At first, pre-processing step is used to amplify and smooth EOG signals. In maximum-minimum value detection we obtain maximum and minimum voltage levels of the eye movements. Furthermore, we determine the peak time of blink to distinguish voluntary blinks from involuntary blinks. Finally, at classification step k-Nearest Neighbouring (k-NN) technique is applied to separate eye movement signals from each other. Several computer simulations are performed to show the effectiveness of the proposed EOG based wheelchair control system. According to the results, proposed system can communicate paralyzed people with their wheelchair and by this way they will be able to move by their selves. -
Electroretinography 1 Electroretinography
Electroretinography 1 Electroretinography Electroretinography measures the electrical responses of various cell types in the retina, including the photoreceptors (rods and cones), inner retinal cells (bipolar and amacrine cells), and the ganglion cells. Electrodes are usually placed on the cornea and the skin near the eye, although it is possible to record the ERG from skin electrodes. During a recording, the patient's eyes are exposed to standardized stimuli and the resulting signal is displayed showing the time course of the signal's Maximal response ERG waveform from a dark adapted eye. amplitude (voltage). Signals are very small, and typically are measured in microvolts or nanovolts. The ERG is composed of electrical potentials contributed by different cell types within the retina, and the stimulus conditions (flash or pattern stimulus, whether a background light is present, and the colors of the stimulus and background) can elicit stronger response from certain components. If a flash ERG is performed on a dark-adapted eye, the response is primarily from the rod system and flash ERGs performed on a light adapted eye will reflect the activity of the cone system. To sufficiently bright flashes, the ERG will contain an A patient undergoing an electroretinogram a-wave (initial negative deflection) followed by a b-wave (positive deflection). The leading edge of the a-wave is produced by the photoreceptors, while the remainder of the wave is produced by a mixture of cells including photoreceptors, bipolar, amacrine, and Muller cells or Muller glia.[1] The pattern ERG, evoked by an alternating checkerboard stimulus, primarily reflects activity of retinal ganglion cells. -
Bass – Glaucomatous-Type Field Loss Not Due to Glaucoma
Glaucoma on the Brain! Glaucomatous-Type Yes, we see lots of glaucoma Field Loss Not Due to Not every field that looks like glaucoma is due to glaucoma! Glaucoma If you misdiagnose glaucoma, you could miss other sight-threatening and life-threatening Sherry J. Bass, OD, FAAO disorders SUNY College of Optometry New York, NY Types of Glaucomatous Visual Field Defects Paracentral Defects Nasal Step Defects Arcuate and Bjerrum Defects Altitudinal Defects Peripheral Field Constriction to Tunnel Fields 1 Visual Field Defects in Very Early Glaucoma Paracentral loss Early superior/inferior temporal RNFL and rim loss: short axons Arcuate defects above or below the papillomacular bundle Arcuate field loss in the nasal field close to fixation Superotemporal notch Visual Field Defects in Early Glaucoma Nasal step More widespread RNFL loss and rim loss in the inferior or superior temporal rim tissue : longer axons Loss stops abruptly at the horizontal raphae “Step” pattern 2 Visual Field Defects in Moderate Glaucoma Arcuate scotoma- Bjerrum scotoma Focal notches in the inferior and/or superior rim tissue that reach the edge of the disc Denser field defects Follow an arcuate pattern connected to the blind spot 3 Visual Field Defects in Advanced Glaucoma End-Stage Glaucoma Dense Altitudinal Loss Progressive loss of superior or inferior rim tissue Non-Glaucomatous Etiology of End-Stage Glaucoma Paracentral Field Loss Peripheral constriction Hereditary macular Loss of temporal rim tissue diseases Temporal “islands” Stargardt’s macular due -
Stargardt's Hereditary Progressive Macular Degeneration
Brit. 7. Ophthal. ( 1972) 56, 8I 7 Br J Ophthalmol: first published as 10.1136/bjo.56.11.817 on 1 November 1972. Downloaded from Stargardt's hereditary progressive macular degeneration A. RODMAN IRVINE AND FLOYD L. WERGELAND, JR From Ophthalmology Service, Letterman General Hospital, Presidio of San Francisco, California In a series of three papers, Stargardt ( 1909,I93, I9I6) described with precision and thoroughness a form of hereditary macular degeneration which has become known as Stargardt's disease. The purposes of the present paper are to review Stargardt's original observations, to argue that Stargardt's disease and fundus flavimaculatus with atrophic macular degeneration are identical, and to present a series of patients studied by fluorescein angiography consistent with the hypothesis that a late secondary or disuse atrophy of the choriocapillaris occurs in Stargardt's disease. Stargardt described four families. The disease seemed to show recessive inheritance, being present in siblings but never in successive generations. Symptoms were usually first noted between 8 and I6 years of age, and then progressed gradually and inexorably until all macular function was destroyed some years later. The first finding was a decrease in visual acuity, often more noticeable in the bright light than in the dark, with minimal by copyright. ophthalmoscopic changes. A faint irregularity in the pigment in the macular region was often all that could be seen at this stage, and the fundus might easily be passed as normal. Later, the foveal reflex was lost. Soft yellow-grey spots appeared in the macula which initially were barely distinguishable from the fundus background. -
Stargardt Disease
Stargardt disease Author: Professor August. F. Deutman1 Creation Date: January 2003 Scientific Editor: Professor Jean-Jacques De Laey 1Institute of Ophthalmology, University Hospital Nijmegen, Postbox 9101, 6500 HB Nijmegen, Netherlands. Abstract Keywords Disease name and synonyms Excluded diseases Definition Frequency Clinical description Management including treatment Etiology Diagnosis References Abstract Stargardt's disease is a form of juvenile hereditary macular degeneration characterized by discrete yellowish round or pisciform flecks around the macula at the level of the retinal pigment epithelium (rpe). Stargardt's disease is the most common hereditary macular dystrophy. Prevalence is estimated between 1 in 8,000 and 1 in 10,000. Disease onset occurs typically in the first or second decade of life and manifests as decreased visual acuity. In the early stages, the macula usually shows discrete rpe changes, followed later by an horizontal ovoid zone of beaten bronze atrophy. In final stages, the macula can be associated with central areolar choroidal dystrophy. Fluorescein angiography reveals the characteristic dark choroid (''silence choroidien''), which probably results from the accumulation of lipofuscin in the rpe. This disease has usually an autosomal recessive inheritance pattern but some dominant pedigrees have been reported. The autosomal type has been associated with mutations in the ABCR gene, which encodes a transmembrane transporter protein expressed by the rod outer segments. There is currently no treatment available for Stargardt's disease. Keywords Stargardt, Macula, Fundus flavimaculatus Disease name and synonyms Definition • Stargardt’s disease Stargardt’s disease (Stargardt, 1909, 1913, • Fundus flavimaculatus 1916, 1917, 1925; Weleber, 1994; Armstrong et al., 1998) is a form of juvenile hereditary macular Excluded diseases degeneration characterized by discrete yellowish • Cone dystrophy round or pisciform flecks around the macula at the level of the retinal pigment epithelium (rpe). -
Assessment and Management of Infantile Nystagmus Syndrome
perim Ex en l & ta a l ic O p in l h t C h f Journal of Clinical & Experimental a o l m l a o n l r o Atilla, J Clin Exp Ophthalmol 2016, 7:2 g u y o J Ophthalmology 10.4172/2155-9570.1000550 ISSN: 2155-9570 DOI: Review Article Open Access Assessment and Management of Infantile Nystagmus Syndrome Huban Atilla* Department of Ophthalmology, Faculty of Medicine, Ankara University, Turkey *Corresponding author: Huban Atilla, Department of Ophthalmology, Faculty of Medicine, Ankara University, Turkey, Tel: +90 312 4462345; E-mail: [email protected] Received date: March 08, 2016; Accepted date: April 26, 2016; Published date: April 29, 2016 Copyright: © 2016 Atilla H. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract This article is a review of infantile nystagmus syndrome, presenting with an overview of the physiological nystagmus and the etiology, symptoms, clinical evaluation and treatment options. Keywords: Nystagmus syndrome; Physiologic nystagmus phases; active following of the stimulus results in poor correspondence between eye position and stimulus position. At higher velocity targets Introduction (greater than 100 deg/sec) optokinetic nystagmus can no longer be evoked. Unlike simple foveal smooth pursuit, OKN appears to have Nystagmus is a rhythmic, involuntary oscillation of one or both both foveal and peripheral retinal components [3]. Slow phase of the eyes. There are various classifications of nystagmus according to the nystagmus is for following the target and the fast phase is for re- age of onset, etiology, waveform and other characteristics. -
Assessing Ocular Activity During Performance of Motor Skills Using Electrooculography Gallicchio, Germano; Cooke, Andrew; Ring, Christopher
University of Birmingham Assessing ocular activity during performance of motor skills using electrooculography Gallicchio, Germano; Cooke, Andrew; Ring, Christopher DOI: 10.1111/psyp.13070 License: Creative Commons: Attribution (CC BY) Document Version Publisher's PDF, also known as Version of record Citation for published version (Harvard): Gallicchio, G, Cooke, A & Ring, C 2018, 'Assessing ocular activity during performance of motor skills using electrooculography', Psychophysiology. https://doi.org/10.1111/psyp.13070 Link to publication on Research at Birmingham portal General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. •Users may freely distribute the URL that is used to identify this publication. •Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. •User may use extracts from the document in line with the concept of ‘fair dealing’ under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain. Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive. -
Author: Dr. Geary Rummler, OD - Northport VAMC Optometric Resident Co-Author: Dr
Author: Dr. Geary Rummler, OD - Northport VAMC Optometric Resident Co-Author: Dr. Mark Hakim, OD - Northport VAMC Optometric Resident Title: A Complicating Case of Glaucoma Suspicion Confounded by Advanced Stargardt’s Disease: Testing and Alternatives for Appropriate Management. Abstract: The profile and testing for Glaucoma is well established, specifically for patients with average vision. This case-report investigates instruments and alternatives that should be emphasized for patients with advanced Stargardt’s Disease and Glaucoma Suspicion. I. Case History • Patient Demographics: 56 year old African American Male • Chief Complaint: Reduced vision, light sensitivity, and difficulty finding things he dropped or misplaced. • Ocular/Medical History: Advanced Stargardt’s, Glaucoma Suspicion, Borderline Diabetes, Hyperlipidemia, Hypertension, Depressive disorder, Back/lumbosacral pain, and Obesity • Medications: Artificial tears, Aspirin, Atenolol, Hydrochlorothiazide, Simvastatin • Other Salient Information: Legally blind under the U.S. Definition and accompanied by guide-dog II. Pertinent Findings • Clinical: Visual Acuity OD: 5ft/63 OS: 5ft/80 with illuminated Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Pupils, EOMs, and slit lamp examination within normal limits. Intraocular Pressure (IOP) 13/13 mm Hg taken by applanation tonometry AM pressure reading. • Physical: Dilated fundus exam (DFE) - optic nerve head (ONH) appearance 0.7 cup to disk ratio with even superior and inferior rim tissue, well perfused, thinnest rim temporally OU. Macula central patch of geographic atrophy OU. Yellow-white flecks pisciform shape scattered throughout posterior pole. • Laboratory Studies: Octopus Visual Field, Goldmann Kinetic Visual Field • Radiology Studies: Fundus Photography, Heidelberg OCT Macula and OCT ONH retinal nerve fiber layer • Others: IOP historical maximum 19/18 mm Hg, Pachymetry 543/533, family history of glaucoma III. -
Gene Therapy for Inherited Retinal Diseases
1278 Review Article on Novel Tools and Therapies for Ocular Regeneration Page 1 of 13 Gene therapy for inherited retinal diseases Yan Nuzbrokh1,2,3, Sara D. Ragi1,2, Stephen H. Tsang1,2,4 1Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY, USA; 2Jonas Children’s Vision Care, New York, NY, USA; 3Renaissance School of Medicine at Stony Brook University, Stony Brook, New York, NY, USA; 4Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, USA Contributions: (I) Conception and design: All authors; (II) Administrative support: SH Tsang; (III) Provision of study materials or patients: SH Tsang; (IV) Collection and assembly of data: All authors; (V) Manuscript writing: All authors; (VI) Final approval of manuscript: All authors. Correspondence to: Stephen H. Tsang, MD, PhD. Harkness Eye Institute, Columbia University Medical Center, 635 West 165th Street, Box 212, New York, NY 10032, USA. Email: [email protected]. Abstract: Inherited retinal diseases (IRDs) are a genetically variable collection of devastating disorders that lead to significant visual impairment. Advances in genetic characterization over the past two decades have allowed identification of over 260 causative mutations associated with inherited retinal disorders. Thought to be incurable, gene supplementation therapy offers great promise in treating various forms of these blinding conditions. In gene replacement therapy, a disease-causing gene is replaced with a functional copy of the gene. These therapies are designed to slow disease progression and hopefully restore visual function. Gene therapies are typically delivered to target retinal cells by subretinal (SR) or intravitreal (IVT) injection. -
Eye Care Documentation Template Documentation Tem- Plate: Conceptual Structure
Eye Care Documentation Template Documentation Tem- plate: Conceptual Structure Contract: VA118-16-D-1008, Task Order (TO): VA-118-16-F-1008-0007, CLIN0009DA Department of Veterans Affairs (VA) Knowledge Based Systems (KBS) Office of Informatics and Information Governance (OIIG) Clinical Decision Support (CDS) Publication date 06/23/2018 Version: 1.0 Eye Care Documentation Template: Documentation Template: Con- ceptual Structure by Knowledge Based Systems (KBS), Office of Informatics and Information Governance (OIIG), and Clinical Deci- sion Support (CDS) Publication date 06/23/2018 Copyright © 2018 B3 Group, Inc. Copyright © 2018 Cognitive Medical Systems, Inc. B3 Group, Inc. NOTICE OF GOVERNMENT COPYRIGHT LICENSE AND UNLIMITED RIGHTS LICENSE Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. Portions of this content are derivative works from content produced by Cognitive Medical Systems, Inc. licensed under the Apache License, Version 2.0. Additional portions of this content are derivative works from content contributed by Motive Medical Intelligence Inc., under Creative Commons Attribution-ShareAlike 4.0. Contributions from 2013-2018 were performed either by US Government employees, or under US Veterans Health Administration contracts. US Veterans Health Administration contributions by government employees are work of the U.S. -
Electrooculography”
ISSN (Print) : 2319-5940 ISSN (Online) : 2278-1021 International Journal of Advanced Research in Computer and Communication Engineering Vol. 2, Issue 11, November 2013 An Overview of “Electrooculography” Uzma Siddiqui1, A.N Shaikh2 EC Department, Savitribai Phule Women’s Engineering College, Aurangabad MH, India 1 EC Department, Savitribai Phule Women’s Engineering College, Aurangabad MH, India 2 Abstract: This paper brings out a new technology of placing electrodes on user’s forehead around the eyes to record eye movements which is called as Electrooculography (EOG. This technology is based on the principle of recording the polarization potential or corneal-retinal potential (CRP), which is the resting potential between the cornea and the retina. This potential is commonly known as electrooculogram. is a very small electrical potential that can be detected using electrodes which is linearly proportional to eye displacement. EOG serves as a means of control for allowing the handicapped, especially those with only eye-motor coordination, to live more independent lives. This is a low cost assistive system for disabled people. The total command control based on EOG permits users to guide it with a enough degree of comfort ability. Keywords:AnalogDigitalConverter(ADC),Electroencefalogram(EEG),Electromyalgy(EMG),Electrooculography (EOG), Rapid Eye Movement(REM),Slow eye movement(SEM). I. INTRODUCTION Electrooculography is a technique for measuring the resting potential of the retina. The resulting signal is called the electrooculogram. An electrooculograph is a device that measures the voltage between two electrodes placed on the face of a subject so it can detect eye movement. Today the use of computers is extended to every field.