Electroretinography in small animal practice


Published: Dec 6, 2017
Keywords:
Dog retina electroretinography
I. K. LIAPIS (Ι. Κ. ΛΙΑΠΗΣ)
Abstract

During the last years, clinical electrophysiology has considerably improved, allowing the evaluation of the retina and visual pathways. In small animal practice, electroretinography is more useful than other diagnostic techniques for the assessment of retinal function, because of the fact that this method doesn't require patient's cooperation. Electroretinography (ERG) is an electrophysiological technique, which measures the retinal action potentials in response to light stimulation. Flash ERG evaluates the function of outer retina and is performed by the using of flashlight units that uniformly stimulate the retina. The evaluation of ERG requires the well understanding of the morphology as well as the physiologic function of the retina. Furthermore, a number of factors, which can influence the quality of the ERG, are totally controlled during the procedure. Because of the fact that electroretinographic values vary, according to many factors and different diagnostic protocols, comparison of results, obtained from different laboratories, would be difficult. Therefore, each veterinary ERG laboratory obtains its own normal values. ERG is indicated, when retinal disease is suspected. ERG can also help to identify the cause of blindness. In small animal practice, the majority of ERGs are performed on candidates for cataract surgery. Other ERG indications include the early diagnosis of central or generalized progressive retinal atrophy (PRA), the differential diagnosis between the sudden acquired retinal degeneration (SARD) and optic neuritis, the glaucoma and many cases of retinal detachments. Furthermore, ERG is used to evaluate the progression of many retinal disorders.

Article Details
  • Section
  • Review Articles
Downloads
Download data is not yet available.
References
Cruz RD, Adachi-UE (1989) Quantitative evaluation of electroretinogram before cataract surgery. Jpn J Ophthalmol, 33(4):451-457
Dewar J, McKendrick J.G. (1873) On the physiological action of light. Trans. Roy. Soc. Endinb., 27,141.
Ekesten B, Narfstrom Κ . (2004) Abnormal dark-adapted ERG in cats heterozygous for a recessively inherited rod-cone degeneration. Veterinary Ophthalmology, 7,1,63-67
Gitter AJ, Stolov WC(1995) Instrumentation and measurement in Electrodiagnostic medicine. Muscle Nerve, 18 (8):799-811
Gouras P. (1970) Electroretinography : some basic principles. Invest Ophthalmol and Visual Science, 9:557-569
Gotch F. (1903) The time relations of the photoelectric changes in the eyeball of the frog by means of colored light. J.Physiol. 29,388
Granit R. (1933) The components of the retinal action potential and their relation to the optic nerve. J.Physiol. 77,207
Dewar J and McKendrick J.G.(1873) On the physiological action of light. Trans.Poy.Soc.Edinb. 27,141
Hamor RE, Gerding PA, Ramsey DT, Whiteley HE, Benson GJ, Schaeffer DJ (2000). Evaluation of short-term increased intraocular pressure on flash and pattern-generated electroretinograms of dogs. Am J Vet Res. 61(9):1087-91
Helmholtz H. (1867) Optique physiologique. Paris. Victor Masson et Fils.
Holmgren F. (1865) Method att objectivera affecten av I jusintryck pa retina. Upsala Lakaref forth, 1,177
Hum SD, Hardman C, Stanley RG.(2003) Day-blindness in three dogsxlinical and electroretinographic findings. Veterinary Ophthalmology, 6,2,127-130
Imbert M. Le traitement rétinien de l'image, Cours de CES d'Ophtalmologie 2001-2002. Ecole Nationale Vétérinaire de Toulouse
Komaromy AM, Smith PJ, Brook DE (1998) Electroretinography in dogs and cats. Compendium of Continuing Education, 20:343-366.
Lazard Ρ et all. (2003) Electrophysiologic Visuelle Sensorielle Appliquée à la Pratique Vétérinaire: Cours de Formation, Lyon Novembre 2003 : S.V.E.R.O.V (Société Française d'Etudes et de Recherches en Ophtalmologie Vétérinaire).
Μιχαήλ Σ.Γ. (1975) Το όργανον της οράσεως in Μιχαήλ Σ.Γ: Συγκριτική ανατομική των κατοικίδιων θηλαστικών, 525-547.
Μόσχος Ν.Μ.(1992) Ηλεκτροαμφιβληστροειδογράφημα In Μόσχος Ν.Μ:Κλινική ηλεκτροφυσιολογία της όρασης. Εκδόσεις ΖΗΤΑ, 1992 29-60
Narfstrom Κ, Andersson BE, Andersson S, Gouras Ρ (1995). Clinical electroretinography in the dog with ganzfeld stimulation:a practical method of examining rod and cone function. Doc Ophthalmol. 90(3):279-90
Narfstrom K, Ekesten B.(1999) Diseases of the canine ocular fundus In Gelati Veterinary Ophthalmology, Lippincott Williams & Wilkins ed Baltimor, 869-933
Narfstrom K, Ekesten B, Rosolen S.G, Spiess B.M, Percicot CL, Ofri R. (2002) Guidelines for clinical electroretinography in the dog. Documenta Ophthalmologica, 105:83-92
Ofri R.(1999) Optics and Physiology of Vision. In Gelati Veterinary Ophthalmology, Lippincott Williams & Wilkins ed Baltimor, 183-216
Ofri R, Dawson WW, Foli Κ, Gelati KN (1993) Chronic ocular hypertension alters local retinal responsiveness. Br J Ophthalmol, 77(8):502-508
Ofri R. (2002) Clinical electrophysiology in veterinary ophthalmology-the past, present and future. Doc.Ophthalmol 104(1):5-16.
Samuelson D.A. Ophthalmic Anatomy. In Gelati Veterinary Ophthalmology, Lippincott Williams & Wilkins ed Baltimor,31-150
Sims H.M. Electrodiagnostic Evaluation of Vision. In Gelati Veterinary Ophthalmology Lippincott Williams & Wilkins ed Baltimor,483-507
Steinberg RH, Reid M, Lacy PL.(1973) The distribution of rods and cones in the retina of the cat. J.Comp.Neurol, 148:229-235
Φωτίου Φ.(1999) Ηλεκτροαμφιβληστροειδογράφημα In Φωτίου Φ: Ηλεκτροφυσιολογίες και Οπτικές Μέθοδοι Διερεύνησης. Εκδόσεις Παρισιάνος, 99-141
Yanase J, Ogawa Η, Ohtsuka Η (1995). Rod and cone components in the dog electroretinogram during and after dark adaptation. J Vet Med Sci. 57(5):877-81.
Most read articles by the same author(s)