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pupillary dilatation reflex

James Q Truong, Kenneth J Ciuffreda
OBJECTIVE: No objective vision biomarker for photosensitivity currently exists. The present study sought to uncover potential biomarkers for photosensitivity within the pupillary light reflex. METHODS: The pupillary light reflex was evaluated in those with mild traumatic brain injury (mTBI) and in normal individuals, with and without photosensitivity, under a range of test conditions. The Neuroptics DP-2000, infrared, binocular pupillometer was used for both binocular stimulation and recording...
October 2016: Military Medicine
James Q Truong, Kenneth J Ciuffreda
PURPOSE: To determine if mTBI adversely affects the pupillary light reflex (PLR). METHODS: The PLR was evaluated in mTBI and compared to normal individuals under a range of test conditions. Nine pupil parameters (maximum, minimum and final pupil diameter, latency, amplitude and peak and average constriction and dilation velocities) and six stimulus conditions (dim pulse, dim step, bright pulse, bright step, bright red step and bright blue step) were assessed in 32 adults with mTBI (21-60 years of age) and compared to 40 normal (22-56 years of age)...
2016: Brain Injury: [BI]
Corinne Kostic, Sylvain V Crippa, Catherine Martin, Randy H Kardon, Martin Biel, Yvan Arsenijevic, Aki Kawasaki
PURPOSE: This study aims to identify which aspects of the pupil light reflex are most influenced by rods and cones independently by analyzing pupil recordings from different mouse models of photoreceptor deficiency. METHODS: One-month-old wild type (WT), rodless (Rho-/-), coneless (Cnga3-/-), or photoreceptor less (Cnga3-/-; Rho-/- or Gnat1-/-) mice were subjected to brief red and blue light stimuli of increasing intensity. To describe the initial dynamic response to light, the maximal pupillary constriction amplitudes and the derivative curve of the first 3 seconds were determined...
May 1, 2016: Investigative Ophthalmology & Visual Science
Giancarlo A Garcia, Philip Ngai, Swapna Vemuri, Jeremiah P Tao
PURPOSE: Adrenergic medications may elevate the upper eyelid and dilate the pupil. The effects of topical phenylephrine on Müller's muscle have been well described. Dilute epinephrine (DE) is a sympathomimetic agent commonly administered in blepharoptosis surgery, and has been shown to elevate the upper eyelid margin when injected subcutaneously. The effects of DE applied topically to the eye, whether intentional or inadvertent during surgery have not been characterized. The purpose of this investigation was to quantify and compare the effects of topical DE and phenylephrine on upper eyelid position and pupil size...
February 12, 2016: Ophthalmic Plastic and Reconstructive Surgery
Olivia A Petritz, David Sanchez-Migallon Guzman, Kate Gustavsen, K Tomo Wiggans, Philip H Kass, Emma Houck, Christopher J Murphy, Joanne Paul-Murphy
UNLABELLED: OBJECTIVE :To determine the mydriatic effects of topical rocuronium bromide administration in Hispaniolan Amazon parrots (Amazona ventralis) and to identify any adverse effects associated with treatment. DESIGN: Randomized crossover study. ANIMALS: 8 healthy adult Hispaniolan Amazon parrots. PROCEDURES: Rocuronium bromide (20 μL/eye; 10 mg/mL) or saline (20 μL/eye; 0.9% NaCl) solution was administered in both eyes of each bird with a 26-day washout period...
January 1, 2016: Journal of the American Veterinary Medical Association
Jelena Karadžić, Natalija Jaković, Igor Kovačević
INTRODUCTION: Adie's (tonic) pupil is a neuro-ophthalmological disorder characterized by a tonically dilated pupil, which is unresponsive to light. It is caused by damage to postganglionic fibers of the parasympathetic innervation of the eye, usually by a viral.or bacterial infection. Adie's syndrome includes diminished deep tendon reflexes. OUTLINE OF CASES: We report data of a 59-year-old female with unequal pupil sizes. She complained of blurred vision and headache mainly while reading...
July 2015: Srpski Arhiv za Celokupno Lekarstvo
Sebastiaan Mathôt, Stefan Van der Stigchel
The eye's pupils constrict (shrink) in brightness and dilate (expand) in darkness. The pupillary light response was historically considered a low-level reflex without any cognitive component. Here, we review recent studies that have dramatically changed this view: The light response depends not only on a stimulus's brightness but also on whether you are aware of the stimulus, whether you are paying attention to it, and even whether you are thinking about it. We highlight the link between the pupillary light response and eye-movement preparation: When you intend to look at a bright stimulus, a pupillary constriction is prepared along with the eye movement before the eyes set in motion...
October 2015: Current Directions in Psychological Science
Noga Cohen, Natali Moyal, Avishai Henik
Adaptive behavior depends on the ability to effectively regulate emotional responses. Continuous failure in the regulation of emotions can lead to heightened physiological reactions and to various psychopathologies. Recently, several behavioral and neuroimaging studies showed that exertion of executive control modulates emotion. Executive control is a high-order operation involved in goal-directed behavior, especially in the face of distractors or temptations. However, the role of executive control in regulating emotion-related physiological reactions is unknown...
December 2015: Biological Psychology
Jacob T Brown, Mark Connelly, Caitlin Nickols, Kathleen A Neville
PURPOSE: The goal of this study was to establish normative values for measurements of quantitative pupillometry in children. METHODS: Quantitative pupillometry measurements were obtained from children between 1 and 18 years of age being seen for either a well child check or other outpatient appointment. RESULTS: Maximum and minimum pupil size increased slightly with age; however, the correlation was weak (r = 0.29 and 0.19, respectively). Similarly weak correlations with age also were observed for maximum constriction velocity (r = -0...
May 2015: Journal of Pediatric Ophthalmology and Strabismus
Wisse P van der Meijden, Bart H W te Lindert, Denise Bijlenga, Joris E Coppens, Germán Gómez-Herrero, Jessica Bruijel, J J Sandra Kooij, Christian Cajochen, Patrice Bourgin, Eus J W Van Someren
Melanopsin-containing retinal ganglion cells have recently been shown highly relevant to the non-image forming effects of light, through their direct projections on brain circuits that regulate alertness, mood and circadian rhythms. A quantitative assessment of functionality of the melanopsin-signaling pathway could be highly relevant in order to mechanistically understand individual differences in the effects of light on these regulatory systems. We here propose and validate a reliable quantification of the melanopsin-dependent Post-Illumination Pupil Response (PIPR) after blue light, and evaluated its sensitivity to dark adaptation, time of day, body posture, and light exposure history...
October 2015: Experimental Eye Research
Vincenzo Scorcia, Andrea Lucisano, Rocco Pietropaolo, Vincenzo Savoca Corona, Giovanni Scorcia, Massimo Busin
PURPOSE: To report the results of a modified big-bubble deep anterior lamellar keratoplasty technique using the intraoperative red reflex to visualize the amount of residual stroma beneath the inserted cannula. METHODS: A total of 132 consecutive keratoconic eyes were included in this retrospective, noncomparative, interventional case series. Before starting surgery, pharmacologic mydriasis was induced in all eyes undergoing a big-bubble deep anterior lamellar keratoplasty procedure...
September 2015: Cornea
Krzysztof Różanowski, Michał Bernat, Agnieszka Kamińska
INTRODUCTION: The purpose of this study was to develop and initially validate an objective, yet quick, method for assessment of human fatigue. This aim can be achieved by the use of an optical, non-contact method of analysis of pupil activity. The study involved 2 phenomena typical for the behavior of the human pupil: pupillary reflex and pupillary movements. The 1st phenomenon is related to the pupillary light reflex (PLR), which presents the results of physiological adaptation mechanisms of the human eye...
2015: International Journal of Occupational Medicine and Environmental Health
Douglas J Lanska
During the U.S. Civil War, nutritional night blindness was a common problem among soldiers forced to subsist of nutritionally inadequate diets, but medical officers typically attributed this complaint to malingering and did not suspect or appreciate a dietary basis. More than 8,000 cases of night blindness were recorded among Union troops, but many cases were not tabulated because of incomplete data for black soldiers and prisoners of war. From 1864 to 1865, during which comparable data were available for both whites and blacks, the average annual cumulative incidence of night blindness was 4...
July 2015: Military Medicine
Stuart R Steinhauer, Ruth Condray, Misha L Pless
Cognitive operations can be detected by reduction of the pupillary light response. Neurophysiological pathways mediating this reduction have not been distinguished. We utilized selective blockade of pupillary sphincter or dilator muscles to isolate parasympathetic or sympathetic activity during cognition, without modifying central processes. Pupil diameter was measured during the light reaction in 29 normal adults under three processing levels: No Task, during an easy task (Add 1), or a difficult task (Subtract 7)...
2015: Journal of Ophthalmology
Erik Gustafsson, Julie Brisson, Christelle Beaulieu, Marc Mainville, Dominique Mailloux, Sylvain Sirois
The emergence of joint attention is still a matter of vigorous debate. It involves diverse hypotheses ranging from innate modules dedicated to intention reading to more neuro-constructivist approaches. The aim of this study was to assess whether 12-month-old infants are able to recognize a "joint attention" situation when observing such a social interaction. Using a violation-of-expectation paradigm, we habituated infants to a "joint attention" video and then compared their looking time durations between "divergent attention" videos and "joint attention" ones using a 2 (familiar or novel perceptual component)×2 (familiar or novel conceptual component) factorial design...
August 2015: Infant Behavior & Development
Merlin D Larson, Matthias Behrends
Portable infrared pupillometers provide an objective measure of pupil size and pupillary reflexes, which for most clinicians was previously only a visual impression. But despite the fact that pupillometry can uncover aspects of how the human pupil reacts to drugs and noxious stimulation, the use of pupillometry has not gained widespread use among anesthesiologists and critical care physicians. The present review is an introduction to the physiology of pupillary reflexes and the currently established clinical applications of infrared pupillometry, which will hopefully encourage physicians to use this diagnostic tool in their clinical practice...
June 2015: Anesthesia and Analgesia
Jessica M Meekins, Sarah C Guess, Amy J Rankin
CASE DESCRIPTION: 5 cats from the same household were examined because of a sudden onset of tremors, obtundation, blindness, and dilated pupils. Approximately 12 hours prior to evaluation, the owner had attempted to treat the cats for suspected ear mite (Otodectes cynotis) infestation by aural administration of a dose of an ivermectin paste intended for oral administration to horses (approx 22 mg/cat; half of the dose was administered into each ear canal). CLINICAL FINDINGS: None of the cats had a menace response; all cats had dilated pupils and decreased pupillary light reflexes...
June 1, 2015: Journal of the American Veterinary Medical Association
Vsevolod Peysakhovich, Mickaël Causse, Sébastien Scannella, Frédéric Dehais
Pupil diameter is a widely-studied cognitive load measure, which, despite its convenience for non-intrusive operator state monitoring in complex environments, is still not available for in situ measurements because of numerous methodological limitations. The most important of these limitations is the influence of pupillary light reflex. Hence, there is the need of providing a pupil-based cognitive load measure that is independent of light conditions. In this paper, we present a promising technique of pupillary signal analysis resulting in luminance-independent measure of mental effort that could be used in real-time without a priori on luminous conditions...
July 2015: International Journal of Psychophysiology
Chien-Chih Chou, Hsin-Han Chen, Yi-Yu Tsai, You-Ling Li, Hui-Ju Lin
BACKGROUND: We reported a case of sudden monocular vision loss after calcium hydroxyapatite (CaHA) injection into the nasal tip and dorsum with detailed retina images. CASE PRESENTATION: A healthy, 35-year-old woman received CaHA filler injection for nose augmentation. Ten minutes after the procedure, she developed nausea, vomiting, headache, ptosis, and left periorbital pain. After 30 minutes, she complained of progressively blurring vision in the left eye. The best-corrected visual acuity (BCVA) in her left eye was 30 cm ahead of hand motion...
2015: BMC Surgery
Willem W A Sleegers, Travis Proulx, Ilja van Beest
In the social psychological threat-compensation literature, there is an apparent contradiction whereby relatively extreme beliefs both decrease markers of physiological arousal following meaning violations, and increase the values affirmation behaviors understood as a palliative responses to this arousal. We hypothesize that this is due to the differential impact of measuring extremism on behavioral inhibition and approach systems following meaning violations, whereby extremism both reduces markers of conflict arousal (BIS) and increases values affirmation (BAS) unrelated to this initial arousal...
May 2015: Biological Psychology
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