Felis ISSN 2398-2950

Ophthalmoscopy: indirect

Contributor(s): Dennis E Brooks, Peter Renwick, David Williams, Claudia Busse

Introduction

  • To examine the eye especially the posterior segment.

Uses

  • Examination of the eye, mainly the lens and posterior segment (vitreous, fundus, optic nerve head).

Advantages

  • Enables view of fundus through some degree of ocular opacity or cloudy media, which preclude direct ophthalmoscopy.
  • Allows fundus examination through small pupil where mydriasis is undesired or not possible.
  • Excellent survey technique allowing large field of view and stereopsis.
  • Allows easier examination of peripheral fundus.
  • Greater working distance   →   increased safety for examiner and less restraint of patient.
  • Facilitates determination of fundus depressions and elevations due to stereopsis.
  • Both hands are on patient's head with binocular indirect technique, so fundus examination is faster and comparison between eyes is easier.
  • A supplemental mirror can be attached to many binocular indirect models, permitting simultaneous visualization by examiner, student, colleague or client.

Disadvantages

  • Low magnification, depending on the condensing lens used.
  • Inverted and reversed, virtual image.
  • Equipment is expensive with binocular models but condensing lens with pen torch are inexpensive and can be used instead with some limitations.

Requirements

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Preparation

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Procedure

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Aftercare

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Further Reading

Publications

Refereed papers

Other sources of information

  • Heinrich C (2014) The ocular examination. In: Gould D & McLellan G (eds) BSAVA Manual of Canine and Feline Ophthalmology. 3rd edn. British Small Animal Veterinary Association.
  • Featherstone H J & Heinrich C (2013) Ophthalmic examination and diagnostics. In: Gelatt K N (ed) Veterinary Ophthalmology. 5th edn. Wiley-Blackwell. pp 533-613.


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