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MiosisAka: Pupil constriction, Consensual Light Reaction, Near Reaction

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  1. Pupil constriction as a normal response
    1. Parasympathetic stimulation
    2. Near reaction (e.g. Reading)
      1. Pupil constriction mediated by Oculomotor Nerve
      2. Other changes with near reaction
        1. Eye convergence under Oculomotor Nerve control
        2. Accomodation (Lenses become more convex)
    3. Bright light results in bilateral pupil constriction
      1. Direct reaction to light in exposed eye
        1. Light strikes retina of affected eye
        2. Signal passed via Optic Nerve to midbrain
        3. Oculomotor Nerve signals same iris to constrict
      2. Consensual light reaction in opposite eye
        1. Midbrain receives signal from exposed eye
        2. Oculomotor Nerve sinals opposite iris to constrict
  2. Abnormal Causes
    1. Mnemonic: COPS
      1. Cholinergic Toxicity
      2. Clonidine
      3. Opiate overdose
        1. Responds to Naloxone (except synthetic opiates)
      4. Organophosphate Toxicity
      5. Phenothiazines
      6. Pilocarpine
      7. Pontine bleed or lesion
      8. Sedative hypnotics (Benzodiazepine)
    2. Horner's Syndrome

Miosis disorder (C0026205)

Definition (MSH)Pupillary constriction. This may result from congenital absence of the dilatator pupillary muscle, defective sympathetic innervation, or irritation of the CONJUNCTIVA or CORNEA.
ConceptsFinding (T033)
ICD9379.42, 379.42
MSHD015877
EnglishConstricted Pupil, Constricted Pupils, Mioses, Miosis, Miosis disorder, MIOSIS NOT D/T MIOTICS, Persistent Mioses, Persistent miosis, PUPILLARY CONSTRICTION, Pupillary Mioses, Pupillary Miosis, PUPILS CONSTRICTED, Small Pupil, Small Pupils
Spanishconstriccion de las pupilas, miosis, miosis persistente
Parent ConceptsUveal Diseases (C0042161), Parasympathomimetic Disorders (C0728821), Pupillary Functions, Abnormal (C0917967), Pupil Disorders (C0034124), Pupil constriction observed (C0728710), Duplicate concept (C1274013), Ambiguous concept (C1274012)
SourcesCST, DXP, ICD9CM, MSH, MTH, MTHICD9, NDFRT, OMIM, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



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