Pupillary light reflex as an objective biomarker for early identification of blastinduced mtbi article pdf available in spine 2s4004. Pupillary reflex measurement predicts insufficient analgesia. Adjustment to closerange vision is known as the near response, while inhibition. In this prospective noninterventional study in a surgical icu of a university hospital, pdr was assessed during tetanic stimulation of 10, 20 or 40 ma immediately before 40. Pupillary reflex definition of pupillary reflex by the free.
Case scenario links pupil abnormalities pupil abnormality oph08 diplopia oph06 infant with strabismus oph09 sudden loss of vision and headache oph05 altered level of consciousness in an adult n04subtitle. Briefly, the left eye was diffusely illuminated with a tungsten lamp s3 in whose beam was inserted an infrared filter f3 wratten no. Pupillary reflex refers to one of the reflexes associated with pupillary function types include. The knee jerk is an example of the simplest type of reflex. A blink response to light develops at about the same time, and the lid may remain closed for as long as light is present the dazzle reflex. Latency of pupillary reflex to light stimulation and its. A reflex is built into the nervous system and does not need the intervention of conscious thought to take effect. The anatomy of the human pupillary light reflex plr pathway is a matter of debate. Increasing stimulus intensity was associated with an increase in direct light reflex amplitude and maximum rate of constriction and redilatation.
Next, note the direct response, meaning constriction of the illuminated pupil, as well as the consensual response, meaning constriction of the opposite pupil. Kumnick 1956 stated that the latency period of pupil constriction is not affected by increasing age 2 but is affected significantly by the pupillary conditions of restitution and decay of restitution at certain age. Jun 19, 2017 in medicine, the pupillary reflex or pupillary light reflex, is the reduction of pupil size in response to light. The pupil provides a window from the outside world to the retina, allowing for the strict regulation of light. A reflex in the midiris region is about 4 mm from the pupillary center, which is roughly 30, or 60.
Pupillary light reflex to light inside the natural blind spot. If a poor quality light source is used, the stimulated pupil may dilate slightly with continued stimulation. Pupillary light reflex, swinging flashlight test, marcus gunn pupil, direct light reflex, consensual light reflex, direct light pupillary reflex loss, relative afferent pupillary defect, afferent pupillary defect, pupil reactivity. Retinal receptor cells bipolar cells ganglion cells optic nerve and tract pretectal nucleus in the midbrain edingerwestphal nucleus two neurone pathway via the oculomotor nerve sphincter pupillae constrictor muscle of iris a fferent visual pathway e fferent. Normally the pupil is black, but on occasion it may appear white.
Apr 15, 2016 it controls light exposure of the retina. While axons involved in vision reach the conscious level after synapse with the lateral geniculate nucleus, the axons involved in the plr synapse with a third neuron in the pretectal nucleus. Feb 06, 2015 abnormalities of pupillary reflexes 27. Pupillary light reflex is an important indicator for the determination of whether an unconscious patients brain is damaged 1,2. Pupillary light reflex definition of pupillary light. The keen practitioner can gain helpful information simply by assessing pupillary responses. This decrease in constriction or widening of the pupil is due to reduced stimulation of the visual pathway by the pupil on the affected side. What happens to the diameter of the right pupil when you briefly shine the flashlight into the right eye. Chromatic pupillary light reflex and its application in. Pupillary reflex definition of pupillary reflex by medical.
Pupillary light reflex pathway part 2 including sample questions duration. Jun 06, 2014 the light reflex the light reflex consist of simultaneous and equal constriction of pupils in response to stimulation of one eye by light pupil constriction is elicited with extremely low intensities and is proportional within limits to both intensities and duration of stimulus. The afferent part of the plr shares some common pathways up to the level of the optic tract with the visual pathways. Pupillary light reflex should be assessed to determine the therapy the patient is to receive, and to evaluate the patients status prior to and subsequent to treatment. The pupillary reaction in the illuminated eye is called the direct response, and the reaction in the other eye is the. This response, called the light reflex, is regulated by three structures. The pupillary light reflex by katie duckler on prezi. Pupillary light reflex synonyms, pupillary light reflex pronunciation, pupillary light reflex translation, english dictionary definition of pupillary light reflex. Northeastern state university, oklahoma college of optometry. Pupillary light reflex eyelid elevation light entering the eye travels along the optic nerve to the pretectal region of the mid brain to cause pupillary constriction through the visceral motor and short ciliary nerve components of the ocular motor nerve. Medical pharmacology and therapeutics fifth edition, 2018. Adaptation of the pupil light reflex 955 the photopupil response was recorded by an infrared television pupillometer green and maaseidvaao, 1967, the details of which are described elsewhere. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
In this prospective noninterventional study in a surgical icu of a university hospital, pdr was assessed during tetanic stimulation of 10, 20 or 40 ma immediately before 40 endotracheal suctionings. Other articles where pupillary light reflex is discussed. The light reflex is the primary determinant of pupil size, with increased light causing the pupil to constrict and reduce the amount of light that reaches the retina. The pupillary light reflex constricts the pupil in response to light, and pupillary constriction is achieved through the innervation of the iris sphincter muscle. 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. Chromatic pupillary light reflex and its application in small animal ophthalmology pupillary light reflex.
Jul 24, 20 this study aimed to evaluate the pupillary dilatation reflex pdr during a tetanic stimulation to predict insufficient analgesia before nociceptive stimulation in the intensive care unit icu. Pupillary reflex definition of pupillary reflex by. The pupillary light reflex plr or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity of light that falls on the retinal ganglion cells of the retina in the back of the eye, thereby assisting in adaptation of vision to various levels of lightnessdarkness. A greater intensity of light causes the pupil to constrict miosismyosis.
A clinical tool for early detection of mtbiconcussion grace lea y. Pupillary light reflex answer the following questions based on experiment 7. Which of the following statements is true of the pupillary light reflex. On admission, neurologic physical examination showed dysarthria, bilateral miosis, slow pupillary light reflex, weakened pharyngeal reflex, reduction in the right limb strength right arm strength grade 45, right leg strength grade 25, and hemihypesthesia of the right limb. Communitybased, crosssectional study including subjects with normal ocular health ages 5079 years. The pupillary light reflex, accommodation and convergence. Pupillary reflex measurement predicts insufficient. Although pupillary response, where the pupil dilates or constricts due to light is not usually called a reflex, it is still usually considered a part of this topic. Assessment of pupillary light reflex using a smartphone. Testing the near response is necessary only if the pupillary light reflex is abnormal. Residency director womack army medical center, fort bragg, nc. In addition, by placing a wide beam at an angle to the iris and turning the light off and on, the clinician can assess the light reflex for segmental defects such as those that occur in eyes with tonic pupils or aberrant regeneration of the oculomotor nerve.
Aug 06, 2015 pupillary light reflex pathway part 2 including sample questions duration. This study aimed to evaluate the pupillary dilatation reflex pdr during a tetanic stimulation to predict insufficient analgesia before nociceptive stimulation in the intensive care unit icu. In bright light causing a smaller pupil opening, the eye has better sharpness and depth of field. Pdf autonomic components of the pupillary light reflex. To determine the ocular anatomical factors influencing the pupillary light reactions to different wavelengths of light, measured with chromatic pupillometry. While axons involved in vision reach the conscious level after synapse with the lateral geniculate nucleus, the axons involved in the plr synapse with a third neuron in the pretectal nucleus most of the axons arising from this nucleus decussate.
Pupillary light reflex definition of pupillary light reflex. Further, we suggest a new strategy of lesion analysis by combining established techniques. Media in category pupillary light reflex the following 7 files are in this category, out of 7 total. By not being able to relay the intensity of the light as accurately as the healthy pupil and visual pathway, the diseased side causes the visual pathway to mistakenly respond to the decrease in. This mechanism bestowed an evolutionary advantage to our ancestors, who relied on a keen visual sense to allow them survive from predators, and to hunt for prey in a multitude of illuminations. Pdf pupillary light reflex as an objective biomarker for. It is a normal response and dependent on the function of the optic nerves and. The pathway begins in the cortex, which exerts a modulatory effect on constriction which is lost during drowsiness and sleep but increased during intense concentration and arousal. Pupillary responses can signal potentially serious problems. When a light stimulus covers the human natural blind spot bs, perceptual fillingin corrects for the missing information inside the bs.
The light reflex the light reflex consist of simultaneous and equal constriction of pupils in response to stimulation of one eye by light pupil constriction is elicited with extremely low intensities and is proportional within limits to both intensities and duration of stimulus. Alpibn vision research laboratory, departments of opholo and physiolo, university of michigan, ann arbor, ichi 48104 receitted 9 october 1971 introduction the receptors which catch the quanta and thereby give rise to a change in pupil size are. Before you begin, examine the diameter of both the left and right pupils. In medicine, the pupillary reflex or pupillary light reflex, is the reduction of pupil size in response to light. During sleep the pupils are partially constricted but still react to light. In the retina is a threeneuron circuit consisting of lightsensitive photoreceptors rods, bipolar cells, and retinal ganglion cells. What are the purposes of the pupillary light reflex. In order for the eye to function properly, specific autonomic functions must maintain adjustment of four types of smooth muscle. Pupil abnormalities dr stephen best consultant ophthalmologist. May 23, 2016 pupillary light reflex is an important indicator for the determination of whether an unconscious patients brain is damaged 1,2. A halving of the diameter cuts the amount of light to decrease by a factor of 4. The pupillary light reflex is a test of the functional integrity of the subcortical afferent and efferent pathways and is reliably present after 31 weeks gestation. Jan 04, 2017 pupillary dilatation is controlled by the sympathetic system and is efferent only.
Direct pupillary responses to continuously increasing irradiances 6. There was a significant increase in the absolute inter. Diagram of pupillary reflex to light stimulus after lowenstein and loewenfeld. Northeastern state university, oklahoma college of. Chromatic pupillary light reflex and its application in small.
596 716 674 134 1215 721 1175 379 249 347 1031 1094 645 1153 1235 1230 772 980 83 1334 823 471 1048 1049 874 74 178 23 959 1589 1589 422 676 751 663 901 640 1212 1407 1323 272 1136 331 592 1433 736 24 1164 351