Equis ISSN 2398-2977

Ultrasonography: eye

Contributor(s): Kristopher Hughes, Graham Munroe

Introduction

  • Ocular ultrasonography is a non-invasive diagnostic procedure useful for examination of the optic globe, orbit and periocular tissues.
  • Ultrasonography can aid in achieving a diagnosis of intraocular and/or extraocular disease, especially when information cannot be obtained by direct visualization or use of other diagnostic techniques due to periocular swelling or opacity of the ocular media. 
  • The procedure is quick and easy to perform in most horses.
  • An understanding of the normal anatomy of the globe, orbit and periocular tissues is important for interpretation of images obtained from healthy and diseased animals.

Uses

  • Investigation of disparity in globe size, eg buphthalmos, microphthalmos    Eyeball: microphthalmos  , and phthisis bulbi    Eyeball: phthisis bulbi  , or position (exophthalmos   Eye: exophthalmos  ).
  • Assessment of the eye when periocular swelling prevents direct examination.
  • Assessment of the eye when opacity of the cornea, anterior segment, lens or posterior segment opacity prevents complete examination.
  • Identification of foreign bodies, tumors   Orbit: neoplasia - primary  , and mineralization within the eye and orbit.
  • Orbital trauma, especially with excessive soft tissue swelling.
  • Lens abnormalities, eg cataracts   Cataract: overview  , lens rupture, lens luxation.
  • Retinal detachment   Retina: detachment  .
  • Aid in the investigation of blindness.

Advantages

  • Readily available in many clinical practices and a conventional 7.5-12 MHz linear or sector probe can be used.
  • Useful as an ancillary aid to diagnosis.
  • Horses usually tolerate the procedure well.
  • Procedure is non-invasive and non-painful.
  • Minimal likelihood of complications.

Disadvantages

  • Initial set costs; ultrasound machine and appropriate transducers for ophthalmic examination.
  • Some experience is necessary for image interpretation.
  • Horses that have ocular/periocular pain may resent having ultrasonography performed.

Requirements

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Preparation

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Procedure

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Hallowell G & Potter T (2010) Practical guide to ocular ultrasonography in horses and farm animals. In Pract 32(3), 90-96 VetMedResource.
  • Hughes K (2009) Ultrasonographic examination of the painful equine eye. Equine Pract 31 (2), 70-76 VetMedResource.
  • Hallowell G D & Bowen I M (2007) Practical ultrasonography of the equine eye. Equine Vet Educ 19 (11), 600-605 VetMedResource.
  • Scotty N C (2005) Ocular ultrasonography in horses. Clin Tech Equine Pract 4 (1), 106-113 VetMedResource.

Other sources of information

  • Whitcomb M B (2002)How to Diagnose Ocular Abnormalities with Ultrasound.Proc AAEP Conference48,272-275.
  • Rantanen N & McKinnon A (1998) Eds Equine Diagnostic Ultrasonography.Williams & Wilkins.


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