II. Physiology: Normal Response

  1. Sympathetic stimulation
  2. Dark lighting conditions
  3. Images
    1. EyePupillaryReactionNeuroPath.png
    2. EyePupillaryReaction.png

III. Causes: Bilateral Dilated Pupil

  1. Carbon Monoxide Poisoning
  2. Hallucinogens (Ketamine, PCP)
  3. Medications and toxins (Mnemonic: AAAS)
    1. Affects may be asymmetric (see unilateral causes below)
    2. Atropine
    3. Anticholinergic Toxicity (e.g. Antihistamines)
    4. Antidepressants (and Serotonin Syndrome)
    5. Sympathomimetics (Cocaine, Amphetamines)

IV. Causes: Unilateral Dilated Pupil

  1. See Also Anisocoria
  2. Comatose patient with non-reactive dilated pupil (Blown Pupil)
    1. Indicative of Brainstem Herniation
  3. Alert patient
    1. Not due to Increased Intracranial Pressure
    2. Acute Glaucoma
    3. Cranial Nerve III compression or paralysis
      1. Posterior Communicating Artery aneurysm
      2. Compression of third nerve (parasympathetic fibers) along its course (e.g. Cavernous Sinus)
    4. Mydriatic drug (e.g. Atropine)
      1. See Bilateral dilated pupil causes above
      2. Cyclopentolate (Cyclogyl)
        1. Commonly used for dilated Eye Exam (duration 6 to 24 hours, up to 2 days in some cases)
      3. Scopolamine
        1. Often used for perioperative Nausea (may result in Mydriasis in first postoperative 1-2 days)
        2. Consider returning travelers who used Motion Sickness patch
          1. Touching patch and then eye may result in Mydriasis
      4. Phenylephrine nasal spray
        1. May traverse lacrimal duct with unilateral effects
      5. Nebulized Ipratropium Bromide (Duoneb)
        1. Ill fitting nebulizer mask result in Mydriasis (typically unilateral)

V. Causes: Dilated pupil does not constrict with Pilocarpine

  1. Local Eye Trauma
  2. Topical Anticholinergic Agent present in eye

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Related Studies

Ontology: Mydriasis (C0026961)

Definition (MSHCZE) Rozšíření zornice (pupily). Za normálních okolností vzniká při slabém osvětlení (umožní průnik většího množství světla do oka). Je zprostředkována svalem (m. dilator pupillae), který je v duhovce a který je inervován sympatikem. Opak: mióza. M. je možné docílit i léky (mydriatika). M. zvyšuje nitrooční tlak (viz glaukom), proto se tyto léky při glaukomu nesmějí podávat. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (MSH) Dilation of pupils to greater than 6 mm combined with failure of the pupils to constrict when stimulated with light. This condition may occur due to injury of the pupillary fibers in the oculomotor nerve, in acute angle-closure glaucoma, and in ADIE SYNDROME.
Concepts Sign or Symptom (T184)
MSH D015878
ICD10 H57.04
SnomedCT 37125009, 123101006, 301940002
French MYDRIASE, Pupilles dilatées, Dilatation des pupilles, DILATATION DE LA PUPILLE, Mydriase
English MYDRIASIS, PUPILS DILATED, Pupil Dilation, Large pupil, Mydriatic pupil, mydriasis (physical finding), mydriasis, mydriasis was noted, Dilatation pupillary, Dilated pupils, Pupils dilated, Mydriasis [Disease/Finding], pupil dilation, dilated pupil, large pupil, pupillary dilation, dilated pupils, pupillary dilatation, large pupils, pupil dilated, pupils dilated, Pupil dilation (finding), Pupil dilation, Pupil dilated, Wide pupil, Dilated pupil, dilatation; pupil, pupil; dilatation, Mydriasis, NOS, Dilated pupil (qualifier value), Dilated pupil [Ambiguous], Pupil dilation -RETIRED-, Mydriasis, Dilation (Pupil), Dilated pupil (finding), Dilated pupil, function (observable entity)
Portuguese MIDRIASE, Pupilas dilatadas, Dilatação da pupila, DILATACAO DAS PUPILAS, Midríase
Spanish MIDRIASIS, pupila midriática, Dilatación pupilar, Pupilas dilatadas, midriasis, función (entidad observable), PUPILAS DILATADAS, midriasis, dilatación de la pupila - RETIRADO -, dilatación de la pupila - RETIRADO - (concepto no activo), dilatación de la pupila, midriasis (calificador), midriasis (entidad observable), pupila dilatada (hallazgo), pupila dilatada, Midriasis
Dutch verwijding pupillen, pupillen verwijd, verwijde pupillen, mydriase, dilatatie; pupil, pupil; dilatatie, Mydriase
German Erweiterung der Pupillen, Pupillen erweitert, erweiterte Pupillen, MYDRIASIS, PUPILLENERWEITERUNG, Mydriase, Pupillenerweiterung, Mydriasis, Pupillendilatation
Italian Dilatazione delle pupille, Pupille dilatate, Midriasi
Japanese 瞳孔散大, 散大瞳孔, 散瞳, サンドウ, サンダイドウコウ, ドウコウサンダイ
Swedish Pupillutvidgning
Czech mydriáza, Rozšířené zornice, Pupilární dilatace, Mydriáza
Finnish Mydriaasi
Russian MIDRIAZ, МИДРИАЗ
Croatian MIDRIJAZA
Polish Rozszerzenie źrenicy
Hungarian Tág pupillák, Pupilla tágulat, Pupillatágulat, Dilatált pupillák
Norwegian Pupilldilatasjon, Mydriasis, Pupillutvidelse