Miosis
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords:: Pupillary constriction; constricted pupil; miotis
Overview
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Miosis is a medical term for constriction of the pupil. It is the opposite of mydriasis. It is seen in a variety of medical conditions, and can also be caused by certain drugs and chemicals. Eye drops used to intentionally cause miosis are known as “miotics”. Extreme miosis is commonly called “pinpoint pupils”, a situation that can be caused by use of opiates.
Diagnosis
CT
Chest CT if Horner’s syndrome is found and to rule out apical lung mass
Treatment
Medical Therapy
Chest CT if Horner’s syndrome is found and to rule out apical lung mass
Primary Prevention
Remove problem causing medications
References
Historical Perspective
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Classifications
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References
Pathophysiology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Pathophysiology
Visual stimuli enters the eye,and through the retinal photoceptors is converted into an electric impulse, carried through the optic nerve (cranial nerve II) to the brain, where it connects to the pretectal nucleus of the high midbrain. It bypasses the lateral geniculate nucleus and the primary visual cortex. 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. Visceromotor nerve axons (which constitute a portion of the III cranial nerve, along with the somatomotor portion derived from the Edinger-Westphal nucleus) synapse on ciliary ganglion neurons, whose parasympathetic axons innervate the constrictor muscle of the iris, producing miosis. [2]
References
Causes
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Luke Rusowicz-Orazem, B.S.
Overview
Miosis is usually caused as a side effect from drugs intending to treat pain, as well as chemotherapy agents. Other common causes include various neurologic and ophthalmologic conditions.
Causes
Common Causes
- Acetaminophen
- Acetylcholine
- Ambenonium
- Camptothecin derivatives
- Carbachol
- Carbamates
- Chemotherapy
- Cholinergic agents
- CodeineÂ
- Dapiprazole
- Demerol
- Diamorphine
- Distigmine
- Donepezil toxicity
- Fentanyl
- Haloperidol
- Mao inhibitors
- Methadone
- Miostat
- Miotics
- Mirtazapine
- Morphine
- Muscarine
- Naphazoline
- Neostigmine
- Olanzapine
- Ondansetron
- Opioid poisoningÂ
- Organophosphates
- Oxycodone
- Oxymetazoline
- Parasympathomimetics
- Pethidine
- Phenoxybenzamine
- Physostigmine
- PilocarpineÂ
- Pyridostigmine
- Quetiapine
- Tetrahydazoline
- Thorazine
- Tramadol
- Trazodone
Causes by Organ System
Causes in Alphabetical Order
- Acetaminophen
- Acetylcholine
- Acute iritis
- Adie’s pupilÂ
- Ambenonium
- Anisocoria
- Argyll robertson pupils
- Camptothecin derivatives
- Cancer chemotherapy drugs
- Carbachol
- Carbamates
- Cerebrovascular arteriosclerosis
- Chemotherapy
- Cholinergic agents
- Clonidine poisoningÂ
- Cluster headache
- CodeineÂ
- Coma
- Corneal foreign body
- Corneal ulcer
- Dapiprazole
- Demerol
- Diamorphine
- Distigmine
- Donepezil toxicity
- Fatal familial insomnia
- Fentanyl
- Haloperidol
- Hereditary disorders
- Hereditary sensorimotor neuropathy type 3
- Heroin
- Horner’s syndrome
- Hyphema
- Intracranial hemorrhage
- Iridocyclitis
- Iritis
- Lateral medullary syndrome
- Mao inhibitors
- Methadone
- Migraine
- Miostat
- Miotics
- Mirtazapine
- Morphine
- Muscarine
- Mustard gas
- Naphazoline
- Neostigmine
- Neuropathy
- Nicotine
- Olanzapine
- Ondansetron
- Opioid poisoningÂ
- Organophosphates
- Oxycodone
- Oxymetazoline
- Pancoast tumorÂ
- Parasympathomimetics
- Parry-romberg syndrome
- Pethidine
- Phencyclidine poisoning
- Phenoxybenzamine
- Physostigmine
- PilocarpineÂ
- Pontine hemorrhage
- Posterior iris synechiae
- Pyridostigmine
- Quetiapine
- Raeder paratrigeminal syndrome
- Stormorken syndrome
- Tacrine toxicity
- Tertiary syphillis
- Tetrahydazoline
- Thorazine
- Tramadol
- Trazodone
- Uveitis
- Wallenberg’s syndrome
References
Differentiating Miosis from other Disorders
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References
Epidemiology and Demographics
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References
Natural History, Complications, and Prognosis
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References
Diagnosis
Diagnosis
History and Symptoms | Physical Examination | Laboratory Findings | X Rays | CT | MRI | Other Imaging Findings | Other Diagnostic Studies
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