Chapter 18 of "Process in Biological Vision"
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Pupil Responses Associated with Coloured Afterimages Are Mediated by the Magno-Cellular Pathway
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Aston Publications Explorer Vision Research 43 (2003) 1423–1432 www.elsevier.com/locate/visres Pupil responses associated with coloured afterimages are mediated by the magno-cellular pathway S. Tsujimura *, J.S. Wolffsohn, B. Gilmartin Neurosciences Research Institute, Aston University, Aston Triangle, Birmingham B4 7ET, UK Received 14 August 2002; received in revised form 27 January 2003 Abstract Sustained fixation of a bright coloured stimulus will, on extinction of the stimulus and continued steady fixation, induce an afterimage whose colour is complementary to that of the initial stimulus; an effect thought to be caused by fatigue of cones and/or of cone-opponent processes to different colours. However, to date, very little is known about the specific pathway that causes the coloured afterimage. Using isoluminant coloured stimuli recent studies have shown that pupil constriction is induced by onset and offset of the stimulus, the latter being attributed specifically to the subsequent emergence of the coloured afterimage. The aim of the study was to investigate how the offset pupillary constriction is generated in terms of input signals from discrete functional elements of the magno- and/or parvo-cellular pathways, which are known principally to convey, respectively, luminance and colour signals. Changes in pupil size were monitored continuously by digital analysis of an infra-red image of the pupil while observers viewed isoluminant green pulsed, ramped or luminance masked stimuli presented on a computer monitor. It was found that the amplitude of the offset pupillary constriction decreases when a pulsed stimulus is replaced by a temporally ramped stimulus and is eliminated by a luminance mask. -
Customer Vision Report (MED 4)
MED 4 (11/25/2020) CUSTOMER VISION REPORT Purpose: Use this form to request vision examination information from your ophthalmologist or optometrist. Instructions: Complete the Customer Information section and have your Ophthalmologist/Optometrist complete the Vision Examination section. The vision examination must be conducted within 90 days prior to submission of the report to DMV. Mail the completed report to the address above. Questions can be referred to Medical Review Services, 804-367-6203. Acceptable standards of vision for safe driving are determined by the Code of Virginia and DMV under the guidance of the Medical Advisory Board. Note: Any charges incurred for the completion of this form are your responsibility. CSC STAFF Do NOT send MED 4 back with daily work unless there is an ocular condition or customer cannot be licensed due to a MED 6 calculation. CUSTOMER INFORMATION (To be completed by customer PRIOR to vision examination) If you change either your residence/home address or mailing address to a non-Virgina address, your driver license or photo identification (ID) card may be cancelled. NAME (last) (first) (mi) (suffix) CUSTOMER NUMBER (from your driver license) or SSN RESIDENCE/HOME ADDRESS BIRTHDATE (mm/dd/yyyy) CITY STATE ZIP CODE CITY OR COUNTY OF RESIDENCE MAILING ADDRESS (if different from above) CITY STATE ZIP CODE DAYTIME TELEPHONE NUMBER VISION EXAMINATION (to be completed by Ophthalmologist/Optometrist) FIRST EXAMINATION DATE MOST RECENT EXAMINATION DATE Does the patient have any visual/ocular condition(s) that could affect the ability to drive a motor vehicle? YES NO If YES, indicate condition below. -
RETINAL DISORDERS Eye63 (1)
RETINAL DISORDERS Eye63 (1) Retinal Disorders Last updated: May 9, 2019 CENTRAL RETINAL ARTERY OCCLUSION (CRAO) ............................................................................... 1 Pathophysiology & Ophthalmoscopy ............................................................................................... 1 Etiology ............................................................................................................................................ 2 Clinical Features ............................................................................................................................... 2 Diagnosis .......................................................................................................................................... 2 Treatment ......................................................................................................................................... 2 BRANCH RETINAL ARTERY OCCLUSION ................................................................................................ 3 CENTRAL RETINAL VEIN OCCLUSION (CRVO) ..................................................................................... 3 Pathophysiology & Etiology ............................................................................................................ 3 Clinical Features ............................................................................................................................... 3 Diagnosis ......................................................................................................................................... -
Real Time Measurement and Processing of Pupillary Light Reflex for Early Detection of Disease
Journal of Computers Real Time Measurement and Processing of Pupillary Light Reflex for Early Detection of Disease Ippei Torii*, Takahito Niwa Aichi Institute of Technology, Dept. of Information Science, 1247 Yachigusa, Yakusa-cho, Toyota, Aichi, Japan. * Corresponding author. Tel.: 81-565-48-8121; email: mac[aitech.ac.jp Manuscript submitted January 10, 2019; accepted March 8, 2019. doi: 10.17706/jcp.14.3.161-169 Abstract: Recently, pupillary measurements have begun to be considered effective in the diagnosis of various physical conditions. Apart from optic neuropathy and retinal disorders, which are ocular diseases, diversions can be expected in the diagnosis of autonomic disturbance due to sympathetic and parasympathetic nerve disorders, cranial nerve disorders, cerebral infarction, depression, and diabetes. In this study, we have developed a real-time pupil diameter measuring system that is inexpensive and does not require a complicated device. When strong light is projected onto the eyeball, this system can measure the reaction time until the start of miosis, the time to achieve maximal miosis, and the difference in reaction speed of the left and right eyes. With this system, the status of a disease can be judged based on the distance from the threshold value. Key words: Real time measurement, eye movement, early detection of disease, image processing. 1. Introduction There are approximately one hundred million photoreceptor cells in the retina of human eyes. Light that shines on those cells is converted to nerve signals, which transmit the information to the brain, resulting in the visual recognition of objects. When light is radiated onto the eye, the pupillary light reflex is triggered, causing the pupillary diameter to decrease with a time delay of less than 1 sec. -
Retinitis Pigmentosa Precision Panel Overview Indications Clinical
Retinitis Pigmentosa Precision Panel Overview Retinitis Pigmentosa (RP) comprises a complex group of inherited dystrophies characterized by degeneration and dysfunction of the retina, affecting photoreceptor and pigment epithelial function. RP can be an isolated finding or be part of a syndrome that can be inherited in a dominant, recessive or X-linked pattern. This disease presents as progressive loss of night and peripheral vision, leading to a constricted visual field and markedly diminished vision. The clinical presentation of these findings is highly variable, some patients being affected during childhood while others are asymptomatic well into adulthood. There is an increase in mortality rate due to psychiatric comorbidities. The Igenomix Retinitis Pigmentosa Precision Panel can be used to make an accurate and directed diagnosis as well as a differential diagnosis of blindness ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes involved. Indications The Igenomix Retinitis Pigmentosa Precision Panel is indicated for those patients with a clinical suspicion or diagnosis with or without the following manifestations: - Family history of RP - Night blindness - Progressive constriction of the visual field, usually peripheral - Cataracts - Sensation of sparking lights (photopsias) - Headache Clinical Utility The clinical utility of this panel is: - The genetic and molecular confirmation for an accurate clinical diagnosis of a symptomatic patient. - Early initiation of multidisciplinary treatment in the form of medical care with vitamin A and other antioxidants and surgical care for potential cataract extraction or retinal prosthesis. -
Subliminal Afterimages Via Ocular Delayed Luminescence: Transsaccade Stability of the Visual Perception and Color Illusion
ACTIVITAS NERVOSA SUPERIOR Activitas Nervosa Superior 2012, 54, No. 1-2 REVIEW ARTICLE SUBLIMINAL AFTERIMAGES VIA OCULAR DELAYED LUMINESCENCE: TRANSSACCADE STABILITY OF THE VISUAL PERCEPTION AND COLOR ILLUSION István Bókkon1,2 & Ram L.P. Vimal2 1Doctoral School of Pharmaceutical and Pharmacological Sciences, Semmelweis University, Budapest, Hungary 2Vision Research Institute, Lowell, MA, USA Abstract Here, we suggest the existence and possible roles of evanescent nonconscious afterimages in visual saccades and color illusions during normal vision. These suggested functions of subliminal afterimages are based on our previous papers (i) (Bókkon, Vimal et al. 2011, J. Photochem. Photobiol. B) related to visible light induced ocular delayed bioluminescence as a possible origin of negative afterimage and (ii) Wang, Bókkon et al. (Brain Res. 2011)’s experiments that proved the existence of spontaneous and visible light induced delayed ultraweak photon emission from in vitro freshly isolated rat’s whole eye, lens, vitreous humor and retina. We also argue about the existence of rich detailed, subliminal visual short-term memory across saccades in early retinotopic areas. We conclude that if we want to understand the complex visual processes, mere electrical processes are hardly enough for explanations; for that we have to consider the natural photobiophysical processes as elaborated in this article. Key words: Saccades Nonconscious afterimages Ocular delayed bioluminescence Color illusion 1. INTRODUCTION Previously, we presented a common photobiophysical basis for various visual related phenomena such as discrete retinal noise, retinal phosphenes, as well as negative afterimages. These new concepts have been supported by experiments (Wang, Bókkon et al., 2011). They performed the first experimental proof of spontaneous ultraweak biophoton emission and visible light induced delayed ultraweak photon emission from in vitro freshly isolated rat’s whole eye, lens, vitreous humor, and retina. -
Theoretical Part Eye Examinations 1
Name and Surrname number Study group Theoretical part Eye examinations 1. Astigmatism Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina. Astigmatism can sometimes be asymptomatic, while higher degrees of astigmatism may cause symptoms such as blurry vision, squinting, eye strain, fatigue, or headaches. Types Regular astigmatism: Principal meridians are perpendicular. Simple astigmatism – the first focal line is on the retina, while the second is located behind the retina, or, the first focal line is in front of the retina, while the second is on the retina. Compound astigmatism – both focal lines are located behind or before the retina. Mixed astigmatism – focal lines are on both sides of the retina (straddling the retina). Irregular astigmatism: Principal meridians are not perpendicular. This type cannot be corrected by a lens. Tests Objective Refractometer, autorefractometer Placido keratoscope – A placido keratoscope consists of a handle and a circular part with a hole in the middle. The hole with a magnifying glass is viewed from a distance of 10–15 cm to the patients cornea. In the 200 mm wide circular portion there are concentric alternating black and white circles. They reflect the patient’s cornea. In the event of astigmatism, a deformation appears at the corresponding location. Sciascope Ophthalmometry Subjective Fuchs figure – This is a tool for evaluating astigmatism where examinee stands up against a pattern of circular shape (circular or striped rectangles) and fixes his/her gaze on the center of the pattern with one open eye. -
Genes in Eyecare Geneseyedoc 3 W.M
Genes in Eyecare geneseyedoc 3 W.M. Lyle and T.D. Williams 15 Mar 04 This information has been gathered from several sources; however, the principal source is V. A. McKusick’s Mendelian Inheritance in Man on CD-ROM. Baltimore, Johns Hopkins University Press, 1998. Other sources include McKusick’s, Mendelian Inheritance in Man. Catalogs of Human Genes and Genetic Disorders. Baltimore. Johns Hopkins University Press 1998 (12th edition). http://www.ncbi.nlm.nih.gov/Omim See also S.P.Daiger, L.S. Sullivan, and B.J.F. Rossiter Ret Net http://www.sph.uth.tmc.edu/Retnet disease.htm/. Also E.I. Traboulsi’s, Genetic Diseases of the Eye, New York, Oxford University Press, 1998. And Genetics in Primary Eyecare and Clinical Medicine by M.R. Seashore and R.S.Wappner, Appleton and Lange 1996. M. Ridley’s book Genome published in 2000 by Perennial provides additional information. Ridley estimates that we have 60,000 to 80,000 genes. See also R.M. Henig’s book The Monk in the Garden: The Lost and Found Genius of Gregor Mendel, published by Houghton Mifflin in 2001 which tells about the Father of Genetics. The 3rd edition of F. H. Roy’s book Ocular Syndromes and Systemic Diseases published by Lippincott Williams & Wilkins in 2002 facilitates differential diagnosis. Additional information is provided in D. Pavan-Langston’s Manual of Ocular Diagnosis and Therapy (5th edition) published by Lippincott Williams & Wilkins in 2002. M.A. Foote wrote Basic Human Genetics for Medical Writers in the AMWA Journal 2002;17:7-17. A compilation such as this might suggest that one gene = one disease. -
Comprehensive Pediatric Eye and Vision Examination
American Optometric Association – Peer/Public Review Document 1 2 3 EVIDENCE-BASED CLINICAL PRACTICE GUIDELINE 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Comprehensive 18 Pediatric Eye 19 and Vision 20 Examination 21 22 For Peer/Public Review May 16, 2016 23 American Optometric Association – Peer/Public Review Document 24 OPTOMETRY: THE PRIMARY EYE CARE PROFESSION 25 26 The American Optometric Association represents the thousands of doctors of optometry 27 throughout the United States who in a majority of communities are the only eye doctors. 28 Doctors of optometry provide primary eye care to tens of millions of Americans annually. 29 30 Doctors of optometry (O.D.s/optometrists) are the independent primary health care professionals for 31 the eye. Optometrists examine, diagnose, treat, and manage diseases, injuries, and disorders of the 32 visual system, the eye, and associated structures, as well as identify related systemic conditions 33 affecting the eye. Doctors of optometry prescribe medications, low vision rehabilitation, vision 34 therapy, spectacle lenses, contact lenses, and perform certain surgical procedures. 35 36 The mission of the profession of optometry is to fulfill the vision and eye care needs of the 37 public through clinical care, research, and education, all of which enhance quality of life. 38 39 40 Disclosure Statement 41 42 This Clinical Practice Guideline was funded by the American Optometric Association (AOA), 43 without financial support from any commercial sources. The Evidence-Based Optometry 44 Guideline Development Group and other guideline participants provided full written disclosure 45 of conflicts of interest prior to each meeting and prior to voting on the strength of evidence or 46 clinical recommendations contained within this guideline. -
Persistent Visual Noise (Visual Snow Syndrome)
Journal of Ophthalmology & Visual Neurosciences Case Report Persistent Visual Noise (Visual Snow Syndrome) This article was published in the following Scient Open Access Journal: Journal of Ophthalmology & Visual Neurosciences Received September 22, 2017; Accepted September 27, 2017; Published October 04, 2017 Al Mamoori Fawwaz* and Moath al Horani Department of Medical Retina and Keywords: Visual Snow, Excitability of the cerebral cortex (Hyper metabolism), Neurophthalmology, Eye Specialty Hospital, Amman, Continuous flickering dots, Migraines Aura Jordan Introduction Visual Snow Syndrom is a disorder of altered visual perception in which the patients eyes similar to the pixels of an old television. see continuous flickering tiny black and white dots across the entire visual field of both The visual noise occurs 24/7 with eyes open and closed. Visual Snow is a part of unique syndrome that is different from visual aura in migrane.it was diagnosed for the first time in 1995 by Dr. Schankin MD Fellow in the department of neurology, University of California, San Francisco. Patients may describe other visual symptoms like floaters, afterimages, flashes in addition to headache, tinnitus, anxiety or depression. Most of the affected patients are young and otherwise healthy, often in the second to the fourth decade of life. The cause of syndrome is unclear [1]. The supposed mechanism is excessive activity or excitability of the cerebral cortex neurons that including the thalamic reticular nucleus, Parietal lobe and pre frontal lobe. ThereMethod is no cure for this syndrome until now [2-4]. her 26vision. y old female, has attended our clinic, complaining from persistent noise in her vision (day and night 24/7) that described as black & white dots in the entire field of sym Also she reported difficulties in night vision in addition to other non-ophthalmic ptoms like headache, tinnitus, loss of appetite and pain in tempero-mandibular joint (Figures 1 and 2). -
Acquired Colour Vision Defects in Glaucoma—Their Detection and Clinical Significance
1396 Br J Ophthalmol 1999;83:1396–1402 Br J Ophthalmol: first published as 10.1136/bjo.83.12.1396 on 1 December 1999. Downloaded from PERSPECTIVE Acquired colour vision defects in glaucoma—their detection and clinical significance Mireia Pacheco-Cutillas, Arash Sahraie, David F Edgar Colour vision defects associated with ocular disease have The aims of this paper are: been reported since the 17th century. Köllner1 in 1912 + to provide a review of the modern literature on acquired wrote an acute description of the progressive nature of col- colour vision in POAG our vision loss secondary to ocular disease, dividing defects + to diVerentiate the characteristics of congenital and into “blue-yellow” and “progressive red-green blindness”.2 acquired defects, in order to understand the type of This classification has become known as Köllner’s rule, colour vision defect associated with glaucomatous although it is often imprecisely stated as “patients with damage retinal disease develop blue-yellow discrimination loss, + to compare classic clinical and modern methodologies whereas optic nerve disease causes red-green discrimina- (including modern computerised techniques) for tion loss”. Exceptions to Köllner’s rule34 include some assessing visual function mediated through chromatic optic nerve diseases, notably glaucoma, which are prima- mechanisms rily associated with blue-yellow defects, and also some reti- + to assess the eVects of acquired colour vision defects on nal disorders such as central cone degeneration which may quality of life in patients with POAG. result in red-green defects. Indeed, in some cases, there might be a non-specific chromatic loss. Comparing congenital and acquired colour vision Colour vision defects in glaucoma have been described defects since 18835 and although many early investigations Congenital colour vision deficiencies result from inherited indicated that red-green defects accompanied glaucoma- cone photopigment abnormalities. -
Optical Coherence Tomography
Eponyms in Ophthalmology: What’s in a Name? What’s in a Name? How do ophthalmic diagnostic findings get their names? Timothy J. Bennett, CRA, OCT-C, FOPS Penn State Hershey Eye Center Hershey, PA SA-5-C What’s in a Name? What’s in a Name? Linnaean Taxonomy: system of Linnaean Taxonomy classification Binomial nomenclature Carl Linnaeus, 1707-1778 What About Human Anatomy? Anatomic Terminology In the late nineteenth century some Nomina Anatomica was the international 50,000 terms for various body parts standard on human anatomic terminology were in use. from 1956 until it was replaced by Terminologia Anatomica in 1998. The same structures were described by different names, depending on the anatomist’s background: school, language, culture, traditions, etc. 1 How About Ophthalmology? Diagnostic Naming Conventions Etymology: origins of words often from Greek or Latin roots Named for anatomic location Descriptive of process or result Descriptive of appearance Acronyms or initials Eponyms: named for first person to identify or describe Etymology Etymology Retinopathy from the Greek “Pathos”: suffering, disease, feeling, passion. Descriptive of Process or Result Descriptive of Process or Result Macular degeneration Vitreo-macular traction Plaquenil toxicity Macular hole 2 Descriptive of Appearance Descriptive of Appearance Literal Synonymous (looks like something else) Pink eye Cherry red spot Floppy lid syndrome Bear tracks Cataract? Ichthyosis Genetic skin disorder characterized by dry, scaly, or flaky skin that resembles