The Effects of Different Anesthetic Agents on Short Electroretinography Protocol in Dogs

Abstract

ABSTRACT. The purpose of this article was to investigate the effects of sedatives and general anesthetics, such as tiletamine-zolazepam, medetomidine, and isoflurane on the short ERG protocol. Six healthy mongrel dogs were assessed by a convenient short ERG protocol with the owners' consent. The amplitudes of a-wave and b-wave, as well as the implicit time of ERG under different anesthesia statuses, were recorded and analyzed. The amplitudes of ERG waves were not significantly different between tiletamine-zolazepam and medetomidine groups, except in b-wave after 5 min dark adaptation (140  42 V in tiletamine-zolazepam and 101  32 V in medetomidine, p<0.01). The amplitude of ERG recorded in isoflurane (5  3 V of a-wave and 12  6 V of b-wave under light adaptation; 41  19 V of b-wave after 1 min dark adaptation; 28  15 V of a-wave and 58  32 V of b-wave after 5 min dark adaptation) were significantly different from tiletamine-zolazepam (8  2 V of a-wave and 24  9 V of b-wave under light adaptation; 117  44 V of bwave after 1 min dark adaptation; 59  18 V of a-wave and 140  42 V of b-wave after 5 min dark adaptation), except in a-wave after 1 min dark adaptation (39  13 V in tiletamine-zolazepam and 34  17 V in isoflurane). Comment-General anesthesia had significantly lower amplitudes in the dark-adapted group compared with the sedation group. Therefore, tiletamine-zolazepam is a desirable choice for the short ERG protocol in dogs.

Electroretinography in dogs: a review

“…This explains the necessity of incorporating general anaesthesia into the ERG protocol. It should be remembered that each anaesthetic exerts a specific impact on ERG recordings (Kommonem 1988; Yanase and Ogawa 1997; Kommonen et al 2007;Norman et al 2008;Jeong et al 2009;Lin et al 2009). An understanding of the correlation between anaesthetics and ERG traces provides a basis for their correct analysis.…”

Normal Clinical Electroretinography Parameters of Healthy Pharaoh Hounddogs

“…The determination of normal ERG values is of great importance for clinical practice, considering that there are numerous intrinsic and extrinsic factors influencing the ERG recordings including the age and breeds of the animal (Itoh et al, 2010), the environment and body temperature (Mizota and Adachi-Usami, 2002), pupil diameter, intraocular pressure and eye movement (Marmor et al, 2009;Grozdanic et al, 2010;Nair et al, 2011), electrode type and position (Mentzer et al, 2005), stage of retinal dark adaptation (Maehara et al, 2015), anesthesia technique (Norman et al, 2008;Lin et al, 2009). All of that contribute to interfere with the values obtained from ERG recording; therefore, the investigations aiming to establish a normal range still continue.…”

<b>Padronização do eletrorretinograma de campo total em cães da raça Yorkshire Terrier</b>

“…A sedação por nós utilizada foi eficaz para a realização dos exames, fato corroborado por outros estudos (KOMÁROMY; SMITH; LEE et al, 2009;LIN et al, 2009;SAFATLE et al, 2010a, b, c;FREEMAN et al, 2013;GÓES et al, 2015). A recuperação foi, em geral, rápida e os animais foram liberados aos proprietários com capacidade motora completa.…”