Anisocoria

Anisocoria

Infobox_Disease
Name = PAGENAME


Caption = Anisocoria
DiseasesDB = 724
ICD10 = ICD10|H|57|0|h|55
ICD9 = ICD9|379.41
ICDO =
OMIM = 106240
MedlinePlus =
eMedicineSubj = emerg
eMedicineTopic = 29
eMedicine_mult = eMedicine2|neuro|479 eMedicine2|oph|160
MeshID = D015875

Anisocoria is a condition characterized by an unequal size of the pupils.

Causes

In the absence of any deformities of the iris or eyeball proper, anisocoria is usually the result of a defect in efferent nervous pathways controlling the pupil traveling in the oculomotor nerve (parasympathetic fibers) or the sympathetic pathways. Physical lesions and drugs causing anisocoria will do so via disruption of these pathways.

Some examples of drugs which may affect the pupils include pilocarpine, cocaine, tropicamide and scopolamine.

Additionally, dilation of the pupil is termed mydriasis and constriction of the pupil is termed miosis.

Interpretation

Clinically, it is important to establish which of the two pupils is behaving abnormally.

* If the "smaller" of the two pupils is the abnormal one, dimming the ambient light will not cause it to dilate, in which case a defect in sympathetic fibers is suspected, as seen in Horner's syndrome.
* Alternatively, if the abnormal pupil is the "larger" one, it will fail to contract in response to light, raising suspicion for a parasympathetic nerve defect, possibly an oculomotor nerve palsy.

A relative afferent pupillary defect or RAPD also known as a Marcus Gunn pupil does not cause anisocoria.

When anisocoria occurs and the examiner is unsure whether the abnormal pupil is the constricted or dilated one, if a one-sided ptosis is present then the abnormally sized pupil can be presumed to be the one on the side of the ptosis.

Anisocoria in the presence of confusion, decreased mental status, severe headache, etc. can be a sign of blood, tumor or other pathology inside the brain pressing down on some critical nerves. This is a neurosurgical emergency requiring emergency treatment and possibly surgery.

ee also

*Mydriasis
*Miosis

References

*"Anisocoria." "Stedman's Medical Dictionary, 27th ed." (2000). ISBN 0-683-40007-X
*Victor, Maurice and Allan H. Ropper. "Adams and Victor's Principles of Neurology, 7th ed." (2001). ISBN 0-07-067497-3

External links

* http://www.kellogg.umich.edu/theeyeshaveit/symptoms/anisocoria.html


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Look at other dictionaries:

  • Anisocoria — Saltar a navegación, búsqueda Anisocoria Clasificación y recursos externos Aviso médico …   Wikipedia Español

  • anisocoria — anisocoría anisocoría f. oftalm. Desigualdad del tamaño pupilar. Medical Dictionary. 2011. anisocoria desigualdad en el diámetro de las pupilas [ICD 1 …   Diccionario médico

  • Anisocoria — An i*so*co ri*a, n. [NL., fr. Gr. ? + ? pupil.] (Med.) Inequality of the pupils of the eye. [Webster 1913 Suppl.] || …   The Collaborative International Dictionary of English

  • Anisocoria — Both pupils are usually of equal size. If they are not, that is termed anisocoria (from a , not + iso , equal + kore , pupil = not equal pupils).The pupil may appear to open (dilate) and close (constrict) but it is really the iris that is the… …   Medical dictionary

  • anisocoria — Eng. Anisocoria Desigualdad en el tamaño de ambas pupilas …   Diccionario de oftalmología

  • anisocoria — /an uy seuh kawr ee euh, kohr , an uy /, n. Ophthalm. inequality in the size of the pupils. [1900 05; ANISO + Gk kór(e) pupil + IA] * * * …   Universalium

  • anisocòria — a|ni|so|cò|ri|a Mot Esdrúixol Nom femení …   Diccionari Català-Català

  • anisocoria — a·ni·so·co·rì·a s.f. TS med. differenza di diametro fra le pupille nelle stesse condizioni di luce {{line}} {{/line}} DATA: 1940. ETIMO: comp. di aniso e 2 coria …   Dizionario italiano

  • anisocoria — pl.f. anisocorie …   Dizionario dei sinonimi e contrari

  • anisocoria — n. inequality of the size of the pupils (Ophthalmology) …   English contemporary dictionary

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