bilateral pupil constriction barbiturates

Other drugs and chemicals that can cause miosis include: Some of the commonly used drugs and chemicals that can cause miosis are opioids, including: loss of the lens of the eye (aphakis) due to surgery or accidentĭrugs and chemicals that can cause miosis.iris inflammation (iridocyclitis, uveitis).intracranial hemorrhage and brain stem stroke.Diseases or conditions that can cause miosisĭiseases or conditions that can cause miosis include: To reach your eye, these nerves pass along your third cranial nerve, also called the oculomotor nerve.Īny disease, drug, or chemical agent that affects these nerves, or the parts of the brain and head that they pass through, can cause miosis. They’re part of the parasympathetic or involuntary nervous system. The iris sphincter muscles are controlled by nerves that originate near the center of your brain. Usually miosis or pupil contraction is caused by a problem with your iris sphincter muscles or the nerves that control them. Visceromotor nerve axons (which constitute a portion of cranial nerve III, along with the somatomotor portion derived from the Edinger-Westphal nucleus) synapse on ciliary ganglion neurons, whose parasympathetic axons innervate the iris sphincter muscle, producing miosis.The size of your pupil is controlled by two counteracting muscles - the iris dilator and the iris sphincter. From the pretectal nucleus neurons send axons to neurons of the Edinger-Westphal nucleus whose visceromotor axons run along both the left and right oculomotor nerves. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. The retinal photoceptors convert light stimuli into electric impulses. Signals from photosensitive ganglion cells have multiple functions including acute suppression of the hormone melatonin, entrainment of the body's circadian rhythms and regulation of the size of the pupil. The ganglion cells give information about ambient light levels, and react sluggishly compared to the rods and cones. Light entering the eye strikes three different photoreceptors in the retina: the familiar rods and cones used in image forming and the more newly discovered photosensitive ganglion cells. In some rare cases, when exposed to mustard gas.Pilocarpine eye drops and all other parasympathomimetics.Mirtazapine, a noradrenergic and specific serotonergic antidepressant ( NaSSA).Some cancer chemotherapy drugs, including camptothecin derivatives.Serotonin antagonists, such as Ondansetron (an anti-emetic) known by its brand name Zofran.Cholinergic agents such as acetylcholine.Antipsychotics, including risperidone, haloperidol, chlorpromazine, olanzapine, quetiapine.Imidazolines such as clonidine, naphazoline, oxymetazoline and tetrahydrozoline.Products containing nicotine such as cigarettes, chewing tobacco or gum.Opioids such as fentanyl, morphine, heroin and methadone (the notable exception being pethidine).Patient also shows ptosis of both eyelids and an inattentive look at the camera, a sign of altered level of consciousness caused by the sedative effect of the drug. Hemorrhage into pons ( intracranial hemorrhage).Senile miosis (a reduction in the size of a person's pupil in old age).Anisocoria is the condition of one pupil being more dilated than the other. The opposite condition, mydriasis, is the dilation of the pupil.

Miosis, or myosis (from Ancient Greek μύειν ( múein) 'to close the eyes'), is excessive constriction of the pupil.

Bilateral pupil constriction barbiturates