A Model of Accommodative-Pupillary Dynamics Stanley Gordon Day Iowa State University
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The Pupillary Light Reflex in the Critically Ill Patient
light must be high for the iris to be seen, which reduces Editorials the step increase induced by the penlight).6 If the pupillary light reflex amplitude is less than 0.3 mm and the maximum constriction velocity is less than 1 mm/s, the reflex is unable to be detected using a The pupillary light reflex in penlight.6 In conscious patients with Holmes-Adie and Argyll-Robertson pupils with ‘absent’ pupillary light the critically ill patient reflexes, small light reflexes have been detected using infrared pupillometry.7 Also in post-resuscitation non- brain dead critically ill patients with ‘absent’ pupillary The pupillary response to light is controlled by the reflexes, the reflex has been demonstrated using a autonomic nervous system. The direct pupillary light portable infrared pupillometer.6 reflex refers to miosis that occurs in the stimulated eye; In this issue of Critical Care and Resuscitation, the consensual pupillary light reflex refers to miosis that Thomas8 describes a case of Guillain Barré syndrome occurs in the other eye. The reflex has a latent period presenting with weakness and fixed dilated pupils who with length of the period, amplitude of the response, and subsequently became ‘locked in’ with absence of any the speed of the pupillary constriction dependent on the clinical response to external stimuli. A positive brain intensity of the stimulus employed.1 For the reflex to be stem auditory evoked response was used to indicate truly tested, an intense stimulus and close observation normal brain stem function. In another recent report, a are required. The reflex has afferent, efferent and central case of ‘reversible fixed dilated pupils’ was associated connections; therefore non-response to light (i.e. -
What's the Connection?
WHAT’S THE CONNECTION? Sharon Winter Lake Washington High School Directions for Teachers 12033 NE 80th Street Kirkland, WA 98033 SYNOPSIS Students elicit and observe reflex responses and distinguish between types STUDENT PRIOR KNOWL- of reflexes. They then design and conduct experiments to learn more about EDGE reflexes and their control by the nervous system. Before participating in this LEVEL activity students should be able to: Exploration, Concept/Term Introduction Phases ■ Describe the parts of a Application Phase neuron and explain their functions. ■ Distinguish between sensory and motor neurons. Getting Ready ■ Describe briefly the See sidebars for additional information regarding preparation of this lab. organization of the nervous system. Directions for Setting Up the Lab General: INTEGRATION Into the Biology Curriculum ■ Make an “X” on the chalkboard for the teacher-led introduction. ■ Health ■ Photocopy the Directions for Students pages. ■ Biology I, II ■ Human Anatomy and Teacher Background Physiology A reflex is an involuntary neural response to a specific sensory stimulus ■ AP Biology that threatens the survival or homeostatic state of an organism. Reflexes Across the Curriculum exist in the most primitive of species, usually with a protective function for ■ Mathematics animals when they encounter external and internal stimuli. A primitive ■ Physics ■ example of this protective reflex is the gill withdrawal reflex of the sea slug Psychology Aplysia. In humans and other vertebrates, protective reflexes have been OBJECTIVES maintained and expanded in number. Examples are the gag reflex that At the end of this activity, occurs when objects touch the sides students will be able to: or the back of the throat, and the carotid sinus reflex that restores blood ■ Identify common reflexes pressure to normal when baroreceptors detect an increase in blood pressure. -
The Pupillary Light Reflex in Normal Subjects
Br J Ophthalmol: first published as 10.1136/bjo.65.11.754 on 1 November 1981. Downloaded from British Journal ofOphthalmology, 1981, 65, 754-759 The pupillary light reflex in normal subjects C. J. K. ELLIS From St Thomas's Hospital, London SE] SUMMARY In 19 normal subjects the pupillary reflex to light was studied over a range of stimulus intensities by infrared electronic pupillography and analysed by a computer technique. Increasing stimulus intensity was associated with an increase in direct light reflex amplitude and maximum rate of constriction and redilatation. Latency from stimulus to onset of response decreased with increas- ing stimulus intensity. The normal range for each of these parameters is given and the significance of these results in clinical pupillary assessment discussed. The technique of infrared pupillometry' has allowed PUPILLOMETRY the normal pupillary response to light to be studied in A Whittaker Series 1800 binocular infrared television detail. Lowenstein and Friedman2 have shown that pupillometer was used in this study. All recordings in response to light the pupil constricts after a latent were made in darkness with no correction for refrac- period and that the length of this latent period, the tive error. The eyes were illuminated from a low- copyright. amplitude of the response, and the speed of the intensity, invisible infrared source and observed by pupillary constriction are dependent on the stimulus means of a closed circuit television system sensitive to intensity employed. These findings have subse- infrared light. The pupils were displayed on television quently been confirmed.3" monitor screens providing instantaneous feedback of Borgmann6 gave 95% confidence limits in defining the quality of the pupil images. -
Binocular Vision
BINOCULAR VISION Rahul Bhola, MD Pediatric Ophthalmology Fellow The University of Iowa Department of Ophthalmology & Visual Sciences posted Jan. 18, 2006, updated Jan. 23, 2006 Binocular vision is one of the hallmarks of the human race that has bestowed on it the supremacy in the hierarchy of the animal kingdom. It is an asset with normal alignment of the two eyes, but becomes a liability when the alignment is lost. Binocular Single Vision may be defined as the state of simultaneous vision, which is achieved by the coordinated use of both eyes, so that separate and slightly dissimilar images arising in each eye are appreciated as a single image by the process of fusion. Thus binocular vision implies fusion, the blending of sight from the two eyes to form a single percept. Binocular Single Vision can be: 1. Normal – Binocular Single vision can be classified as normal when it is bifoveal and there is no manifest deviation. 2. Anomalous - Binocular Single vision is anomalous when the images of the fixated object are projected from the fovea of one eye and an extrafoveal area of the other eye i.e. when the visual direction of the retinal elements has changed. A small manifest strabismus is therefore always present in anomalous Binocular Single vision. Normal Binocular Single vision requires: 1. Clear Visual Axis leading to a reasonably clear vision in both eyes 2. The ability of the retino-cortical elements to function in association with each other to promote the fusion of two slightly dissimilar images i.e. Sensory fusion. 3. The precise co-ordination of the two eyes for all direction of gazes, so that corresponding retino-cortical element are placed in a position to deal with two images i.e. -
On Voluntary Ocular Accommodation
Perception & Psychophysics IPS, Vol. 17 (2),209-212 On voluntary ocular accommodation ROBERT R. PROVINE University ofMaryland Baltimore County, 5401 Wilkins A venue, Baltimore, Marylq,nd 21228 and JAY M. ENOCH Department ofOphthalmology, University of Florida CoUege of Medicine, GainesviUe, Florida 32610 Young observers were challenged to induce a marked monocular accommodative response to a relatively weak accommodative stimulus by placing a-9 diopter contact lens on the eye. At first, observers could not produce the desired response, but with training, three of four subjects achieved criterion. Both a voluntary accommodative response and a response to an adequate accommodative stimulus were apparently involved. The voluntary component of the response could be demonstrated by having the observers repeat the task in total darkness. Accommodation is a change in the curvature and a monocularly presented stimulus pattern which consisted of two thickness ofthe crystalline lens which is made in order. horizontal rectangles of light (each measuring 2"12' x 1°SO' and to bring light from near objects into focus on the separated by 44' measured at the entrance pupil of the eye). A small tixation point was centered between the two rectangles. The field retina. At this time we have limited understanding of was focused at intinity by the optical system. that is, the target array the nature of the adequate stimulus for was located at the focal point of a field lens. The system was a accommodation (Campbell & Westheimer, 1959) and classical Badal optometer (Ogle. 1%1) incorporated in a the extent to which the response is innate (reflexive) or Stiles-Crawford (S-C) apparatus (Enoch & Hope, 1972) that was moditied for SoC peak tinding determinations (Blank, Provine, & learned (Fincham, 1951; Heath, 1956; Campbell, Enoch. -
Pupils and Near Vision
PUPILS AND NEAR VISION Akilesh Gokul PhD Research Fellow Department of Ophthalmology Iris Anatomy Two muscles: • Radially oriented dilator (actually a myo-epithelium) - like the spokes of a wagon wheel • Sphincter/constrictor Pupillary Reflex • Size of pupil determined by balance between parasympathetic and sympathetic input • Parasympathetic constricts the pupil via sphincter muscle • Sympathetic dilates the pupil via dilator muscle • Response to light mediated by parasympathetic; • Increased innervation = pupil constriction • Decreased innervation = pupil dilation Parasympathetic Pathway 1. Three major divisions of neurons: • Afferent division 2. • Interneuron division • Efferent division Near response: • Convergence 3. • Accommodation • Pupillary constriction Pupil Light Parasympathetic – Afferent Pathway 1. • Retinal ganglion cells travel via the optic nerve leaving the optic tracts 2. before the LGB, and synapse in the pre-tectal nucleus. 3. Pupil Light Parasympathetic – Efferent Pathway 1. • Pre-tectal nucleus nerve fibres partially decussate to innervate both Edinger- 2. Westphal (EW) nuclei. • E-W nucleus to ipsilateral ciliary ganglion. Fibres travel via inferior division of III cranial nerve to ciliary ganglion via nerve to inferior oblique muscle. 3. • Ciliary ganglion via short ciliary nerves to innervate sphincter pupillae muscle. Near response: 1. Increased accommodation Pupil 2. Convergence 3. Pupillary constriction Sympathetic pathway • From hypothalamus uncrossed fibres 1. down brainstem to terminate in ciliospinal centre -
Pupillary Light Reflex in Children with Autism Spectrum Disorders
PUPILLARY LIGHT REFLEX IN CHILDREN WITH AUTISM SPECTRUM DISORDERS _______________________________________________________ A Dissertation presented to the Faculty of the Graduate School at the University of Missouri‐Columbia _______________________________________________________ In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy _______________________________________________________ by CHATHURI DALUWATTE Dr. Gang Yao, Dissertation Supervisor MAY 2013 The undersigned, appointed by the dean of the Graduate School, have examined the dissertation entitled PUPILLARY LIGHT REFLEX IN CHILDREN WITH AUTISM SPECTRUM DISORDERS presented by Chathuri Daluwatte, a candidate for the degree of Doctor of Philosophy, and hereby certify that, in their opinion, it is worthy of acceptance. Dr. Gang Yao, Department of Biological Engineering Dr. Judith H. Miles, Thompson Center for Autism & Neurodevelopmental Disorders Dr. Shawn Christ, Department of Psychological Sciences, Thompson Center for Autism & Neurodevelopmental Disorders Dr. Shinghua Ding, Department of Biological Engineering Dr. John Viator, Department of Biological Engineering To Ammi… ACKNOWLEDGEMENTS I wish to express my heartiest gratitude to Dr. Gang Yao, who has served as my advisor during the past four and half years. The inspiration he has been setting was a major driving force throughout my research and I will forever be grateful to Dr. Yao for the challenging way he improved my logical thinking, scientific methodology and professionalism. My deep appreciation is expressed to Dr. Judith H. Miles, for her warmest encouragements, insights and all the guidance throughout the research. She has been a great inspiration for me. I am grateful to Dr. Shawn Christ and Dr. David Beversdorf for their valuable contributions which tremendously improved the quality of this research. I would also like to express my gratitude for Jill Akers and Nicole Takahashi for their amazing job in recruiting and coordinating such a large number of research participants. -
The Role of Focus Cues in Stereopsis, and the Development of a Novel Volumetric Display
The role of focus cues in stereopsis, and the development of a novel volumetric display by David Morris Hoffman A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Vision Science in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY Committee in charge: Professor Martin S. Banks, Chair Professor Austin Roorda Professor John Canny Spring 2010 1 Abstract The role of focus cues in stereopsis, and the development of a novel volumetric display by David Morris Hoffman Doctor of Philosophy in Vision Science University of California, Berkeley Professor Martin S. Banks, Chair Typical stereoscopic displays produce a vivid impression of depth by presenting each eye with its own image on a flat display screen. This technique produces many depth signals (including disparity) that are consistent with a 3-dimensional (3d) scene; however, by using a flat display panel, focus information will be incorrect. The accommodation distance to the simulated objects will be at the screen distance, and blur will be inconsistent with the simulated depth. In this thesis I will described several studies investigating the importance of focus cues for binocular vision. These studies reveal that there are a number of benefits to presenting correct focus information in a stereoscopic display, such as making it easier to fuse a binocular image, reducing visual fatigue, mitigating disparity scaling errors, and helping to resolve the binocular correspondence problem. For each of these problems, I discuss the theory for how focus cues could be an important factor, and then present psychophysical data showing that indeed focus cues do make a difference. -
MDMA Enhances Or Impairs Accuracy of Mental State Decoding Depending on Emotional Valence of the Stimuli
Hysek and Liechti Effects of MDMA on the pupillary light reflex on its own and after pretreatment with reboxetine, duloxetine, clonidine, carvedilol, and doxazosin Cédric M. Hysek and Matthias E. Liechti* Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Department of Internal Medicine, University Hospital and University of Basel, Switzerland Running title: MDMA and pupillary function *Corresponding author: Matthias E. Liechti, Division of Clinical Pharmacology and Toxicology, University Hospital Basel, Hebelstrasse 2, CH-4031 Basel. Phone: +41 61 328 68 68; Fax: +41 61 265 45 60; E-mail: [email protected] 1 Hysek and Liechti Abstract Rationale: Pupillometry can be used to characterize autonomic drug effects. Objective: To determine the autonomic effects of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) on pupillary function, administered alone and after pretreatment with reboxetine, duloxetine, clonidine, carvedilol, and doxazosin. Methods: Infrared pupillometry was performed in five placebo-controlled randomized clinical studies. Each study included 16 healthy subjects (eight men, eight women) who received placebo-MDMA (125 mg), placebo-placebo, pretreatment-placebo, or pretreatment-MDMA using a crossover design. Results: MDMA produced mydriasis, reduced the response to light, prolonged the latency to the light reflex, and shortened the recovery time. The impaired reflex response was short-lasting and associated with subjective, cardiostimulant, and hyperthermic drug effects and returned to normal within 5-6 h after MDMA administration when plasma MDMA levels were still high. Mydriasis was associated with the changes in plasma MDMA concentration over time and longer-lasting. Both reboxetine and duloxetine interacted with the effects of MDMA on pupillary function. Duloxetine even prevented MDMA-induced impairments in the light reflex response despite having similar effects when administered alone. -
Loss of Pupillary Reflex, Retinal and Optic Nerve Degeneration, in Partial
Visual System Pathology Caused by Clironic Cerebral Hypoperfusion: Loss of Pupillary Reflex, Retinal and Optic Nerve Degeneration, and the Role of Light Toxicity by William Dale Stevens A thesis submitted to the Faculty of Graduate Studies and Research in partial filfilment of the requirements for the degree of Master of Science (Specialitation in Neuroscience) Department of Psychology and the Carleton Institute of Neuroscience Carleton University Ottawa, Ontario September, 2000 Q 2000 William Dale Stevens National Library Bibliothèque nationale of Canada du Canada Acquisitions and Acquisitions et Bibliographie Services services bibliographiques 395 Wellington Street 395. rua Wellington Ottawa ON K1A ON4 ûüawaON KIAN Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Cana& to Bibliothèque nationale du Canada de reproduce, loan, dismibute or sell reproduire, prêter, distribuer ou copies of this thesis in microfonn, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/film, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fkom it Ni la thèse ni des extraits substantiels may be pniited or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. S prague-Dawley rats undenvent permanent bilateral ligation of the common carotid arteries (ZVO)(~63) or sham surgery (n=20). Half of the rats were post- surgically housed in constant darkness, the other half in a standard 12-hour light/dark environment. -
Forward and Inward Movement of the Ciliary Muscle Apex with Accommodation in Adults
Forward and Inward Movement of the Ciliary Muscle Apex with Accommodation in Adults THESIS Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Trang Pham Prosak Graduate Program in Vision Science The Ohio State University 2014 Master's Examination Committee: Melissa D. Bailey, OD, PhD, Advisor Donald O. Mutti, OD, PhD Marjean Kulp, OD, PhD Copyright by Trang Pham Prosak 2014 Abstract Purpose: to study the inward and forward movement of the ciliary muscle during accommodation and to investigate the effects of one hour of reading on the ciliary muscle behavior in young adults. Methods: Subjects included 23 young adults with a mean age of 23.7 ± 1.9 years. Images of the temporal ciliary muscle of the right eye were obtained using the Visante™ Anterior Segment Ocular Coherence Tomography while accommodative response was monitored simultaneously by the Power-Refractor. Four images were taken at each accommodative response level (0, 4.0 and 6.0 D) before and after one hour of reading. Ciliary muscle thickness was measured at every 0.25 mm posterior to the scleral spur. SSMAX, which is the distance between scleral spur and the thickest point of the muscle (CMTMAX), was also measured. The change in the ciliary muscle thickness and SSMAX with accommodation from 0 to 4.0 D and 0 to 6.0 D was calculated. Paired t-tests were used to determine if the ciliary muscle thickness and SSMAX for the 4.0 and 6.0 diopters of accommodative response were different after one hour of reading. -
THE PUPIL Alpha Omega Pupil the PUPIL Alpha Omega Pupil
THE PUPIL Observation and Grading Alpha Omega Pupil JohnJohn J. J. Pulaski,Pulaski, O.D.,O.D., FCSOFCSO CollegeCollege ofof SyntonicSyntonic OptometryOptometry 101101 CourseCourse May 2020 Pulaski AO Pupil The Pupil And Syntonics How do you know if a person needs Syntonic Treatment? Pulaski AO Pupil The Pupil And Syntonics Three keys elements in Syntonic Clinical evaluationevaluation andand treatmenttreatment application.application. 1. The Pupil - AO 2.2. The The FieldField -- Kinetic Kinetic 3.3. The The PatientPatient HistoryHistory Pulaski AO Pupil Pulaski AO Pupil The Pupil One of the most sensitive measures of ANS activity. •• ANS/Brainstem ANS/Brainstem functionfunction •• “Eyes “Eyes areare thethe windowwindow toto thethe Soul”Soul” TheThe PupilsPupils areare thethe window.window. •• Portal Portal ofof EnergyEnergy ReceptionReception andand Projection.Projection. PortalPortal throughthrough whichwhich we interact with our world •• Non-verbal Non-verbal CommunicationCommunication andand strongstrong emotionalemotional indicatorindicator .. •• Reception Reception ofof “nutrition”“nutrition” - - LIGHT LIGHT Pulaski AO Pupil Pulaski AO Pupil The Pupil Neurological Pathways ParasympatheticParasympathetic -- Constriction Constriction •The•The PupillaryPupillary LightLight ReflexReflex (PLR)(PLR) •Influence•Influence onon IrisIris SphincterSphincter •Light-Inhibited•Light-Inhibited SympatheticSympathetic PathPath •Trigeminal•Trigeminal NerveNerve –– sensory sensory stimulationstimulation toto eye/iriseye/iris SympatheticSympathetic ––