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Anisocoria of the Small Pupil

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  • First Online:
Encyclopedia of Ophthalmology

  • 86 Accesses

Synonyms

Anisocoria; Horner syndrome; Horner’s syndrome; Miosis; Oculosympathetic paresis

Definition

Anisocoria refers to a difference in pupil size (typically >0.4 mm) between the two eyes. Miosis refers to pupillary constriction and mydriasis to relative dilation. Horner syndrome (HS) is characterized by the clinical constellation of ipsilateral miosis, ptosis (and upside down ptosis), and variable facial or body anhidrosis resulting from oculosympathetic paresis (i.e., damage to the sympathetic nervous system supplying the pupil and eyelid).

Etiology

Causes of anisocoria resulting from an abnormally small pupil include:

  1. I.

    Ocular disease

    1. 1.

      Anterior uveitis (i.e., posterior synechiae)

    2. 2.

      Prior ocular surgery (e.g., iris damage)

    3. 3.

      Pseudoexfoliation syndrome

  2. II.

    Pharmacologic miosis (e.g., pilocarpine eye drops or other miotics)

  3. III.

    Horner syndrome (HS)

    1. 1.

      First order

    2. 2.

      Second order

    3. 3.

      Third order

The ocular sympathetic pathway is a three neuron arc. The first-order neurons lie in...

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Further Reading

  • Bardorf CM, Van Stavern G, Garcia-Valenzuela E (n.d.) Horner syndrome. In: Hampton R (ed) Medscape. http://emedicine.medscape.com/article/1220091. Accessed 15 Jul 2013

  • Brazis PW, Maseu JC, Biller J (2007) Chapter 8. The localization of lesions affecting the ocular motor system. In: Localization in clinical neurology, 5th edn. Lippincott Williams & Wilkins, Philadelphia

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  • Kawasaki A (2006) Chapter 16. Disorders of pupillary function, accommodation, and lacrimation. In: Miller NR, Newman NJ (eds) Walsh & Hoyt’s clinical neuro-ophthalmology, 6th edn. Lippincott Williams & Wilkins, Philadelphia

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  • Reede DL, Garcon E, Smoker WR, Kardon R (2008) Horner’s syndrome: clinical and radiographic evaluation. Neuroimaging Clin N Am 18(2):369085, xi

    Article  Google Scholar 

  • Rucker JC (2012) Chapter 16. Pupillary and eyelid abnormalities. In: Daroff RB, Fenichel GM, Jakovic J, Mazziotta JC (eds) Bradley’s neurology in clinical practice, 6th edn. Saunders, Philadelphia

    Google Scholar 

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Author information

Authors and Affiliations

  1. Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, 6560 Fannin Street, Scurlock 450, Houston, TX, 77030, USA

    Michael L. Morgan, Sumayya J. Almarzouqi & Andrew G. Lee

  2. Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell Medical College, Houston, TX, USA

    Andrew G. Lee

  3. Department of Ophthalmology, The University of Texas Medical Branch, Galveston, TX, USA

    Andrew G. Lee

  4. Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA

    Andrew G. Lee

  5. Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, IA, USA

    Andrew G. Lee

Authors
  1. Michael L. Morgan
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  2. Sumayya J. Almarzouqi
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  3. Andrew G. Lee
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Corresponding author

Correspondence to Andrew G. Lee .

Editor information

Editors and Affiliations

  1. Dept of Ophthal & Optometry,AKH, Medical University of Wien Dept of Ophthal & Optometry,AKH, Wien, Austria

    Ursula Schmidt-Erfurth

  2. Department of Ophthalmology, Goethe University of Frankfurt am Main Department of Ophthalmology, Frankfurt am Main, Germany

    Thomas Kohnen

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© 2015 Springer-Verlag Berlin Heidelberg (outside the USA)

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Morgan, M.L., Almarzouqi, S.J., Lee, A.G. (2015). Anisocoria of the Small Pupil. In: Schmidt-Erfurth, U., Kohnen, T. (eds) Encyclopedia of Ophthalmology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-35951-4_1159-1

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  • DOI: https://doi.org/10.1007/978-3-642-35951-4_1159-1

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  • Publisher Name: Springer, Berlin, Heidelberg

  • Online ISBN: 978-3-642-35951-4

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