ISSN 2398-2977      

Eye: electroretinography

pequis
Contributor(s):

Tim Knott

Ruth Morgan

Synonym(s): ERG


Introduction

  • Equine ophthalmology is an ever advancing field of veterinary medicine.
  • Equine recurrent uveitis   Uveitis: recurrent  is one of the most common conditions of the horse and can result in retinal dysfunction and visual impairment.
  • Retinal function is difficult to assess in veterinary species and visible changes to the retina do not always accurately reflect changes in function.
  • Electroretinography (ERG) is a technique used to record and assess the electrical function of the retina, the optic nerve and the central visual pathways. Visual function can only currently be assessed as a behavioral response.
  • ERG works by recording electrical potentials generated by the retinal cells when light reaches them.
  • The electrical potentials are detected by an electrode placed on the cornea.
  • By varying the light adapted state of the retina and the properties of the light stimulus the ERG trace can give information about specific photoreceptor dysfunction.

Uses

  • The objective assessment of the function integrity of the retina, optic nerve and central visual pathways.
  • Assessment of retinal function prior to cataract surgery   Lens: cataract 08 - mature  .
  • Diagnosis of specific retinal disease, eg congenital stationary night blindness in the Appaloosa   Eye: night blindness  .
  • Investigation of sudden onset blindness where retina may be normal, eg optic   Optic nerve: neuritis  , ischemic optic neuropathy   Eye: ischemic optic neuropathy  .

Advantages

  • It provides an objective assessment of retinal function and can help with prognosticating in cases of equine recurrent uveitis or other diseases affecting the retina.

Disadvantages

  • Specialized expertise and equipment are required to perform ERG.

Requirements

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Preparation

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Procedure

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Komoromy A M, Andrew S E, Sapp H L et al (2003) Flash electroretinography in standing horses using the DTL microfiber electrode. Vet Ophthal (1), 27-33 PubMed.
  • Narfstrom K, Ekesten B, Rosolen S G et al (2002) Guidelines for clinical electroretinography in the dog. Docu Ophthalmol 105 (2), 83-92 PubMed.
  • Gouras P (1970) Electroretinography: Some basic principles. Invest Ophthal (8), 557-569 PubMed.

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code