In mammals, the pupillary light reflex is mediated by intrinsically photosensitive melanopsin-containing retinal ganglion cells that also receive input from rod-cone photoreceptors. To assess the relative contribution of melanopsin and rod-cone photoreceptors to the pupillary light reflex in humans, we compared pupillary light responses in normally sighted individuals (n = 24) with a blind indi...

Pupillary dilation in response to sound stimuli is well established and is generally considered to represent a startle reflex to sound. We believe that the auditory-pupillary response represents not only a simple startle reflex to sound stimuli but also represents a reaction to stimulation of other sense organs, such as otolith organs. Eight young healthy volunteers without a history of hearing...

Amblyopia is much more than decreased vision, it is a syndrome. The variety of deficits is a result of structural and functional differences in the visual pathway from the retina to the cortex. Historically, it was thought that amblyopia did not cause a relative afferent pupillary defect, but recent studies suggest otherwise. Research into the thalamic and cortical influences on the pupillary p...

BACKGROUND Relative afferent pupillary defects are typically related to ipsilateral lesions within the anterior visual pathways. OBJECTIVE To describe a patient who had a workup for headache and was found to have an isolated left relative afferent pupillary defect without any other neurological findings. DESIGN We review the neuroanatomy of the pupillary light reflex pathway and emphasize t...

UNLABELLED Autonomic nervous system disturbances such as pupillary abnormalities have rarely been evaluated in multiple sclerosis (MS). However, pupillary impairment is not uncommon in MS and its origin is still unclear. The aim of this study was to investigate pupillary disturbances in MS and to try to correlate pupillary defects with spinal cord and brainstem magnetic resonance imaging (MRI) ...

We describe a patient with a left trochlear nerve paresis and a left relative afferent pupillary defect despite normal visual acuity, color vision, visual fields, and fundus examination. Magnetic resonance imaging revealed a lesion in the right dorsal midbrain extending from the brachium of the superior colliculus to the inferior colliculus. The anatomy and physiology of the pupillary light ref...

PURPOSE A recent study has shown that retinal ganglion cells containing the photopigment melanopsin, which are intrinsically photosensitive in primates, project to the pupillary control centre in the pretectum. The aim of this study was to investigate how melanopsin retinal ganglion cells (mRGCs) contribute to the pupillary pathway. METHODS We designed and built a novel multi-primary stimulat...

Characteristics of light-induced pupillary oscillations at constant light intensities have been investigated sparsely compared to sleepiness-related pupillary oscillations in darkness. This study presents the first controlled analysis of light-induced pupillary oscillations and their relationship to illumination. Pupillary oscillations of alert subjects were recorded by infrared video pupillogr...

Pupillary dysfunction, a concerning finding in the neurologic examination of the patient with an acute traumatic brain injury often dictates the subsequent treatment paradigm. Patients were monitored closely with an infrared pupillometer, with NPi technology, for acute changes in pupillary function. NPi technology applies a scalar value to pupillary function. A retrospective chart review was pe...