Anisocoria 3039626 194876173 2008-02-29T11:54:01Z Graham87 194203 /* Interpretation */ disambig link {{Infobox_Disease | Name = {{PAGENAME}} | Image = Anizokoria.JPG | 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 [[pupil]]s. ==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 (eyelid)|ptosis]] is present then the abnormally sized pupil can be presumed to be the one on the side of the ptosis. ==See 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 {{Eye pathology }} [[Category:Ophthalmology]] [[Category:Medical signs]] {{eye-stub}} {{med-sign-stub}} [[de:Anisokorie]] [[es:Anisocoria]] [[fr:Anisocorie]] [[it:Anisocoria]] [[nl:Anisocorie]] [[pl:Anizokoria]] [[pt:Anisocoria]] [[sr:Анизокорија]]