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

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 microV in tiletamine-zolazepam and 101 +/- 32 microV in medetomidine, p<0.01). The amplitude of ERG recorded in isoflurane (5 +/- 3 microV of a-wave and 12 +/- 6 microV of b-wave under light adaptation; 41 +/- 19 microV of b-wave after 1 min dark adaptation; 28 +/- 15 microV of a-wave and 58 +/- 32 microV of b-wave after 5 min dark adaptation) were significantly different from tiletamine-zolazepam (8 +/- 2 microV of a-wave and 24 +/- 9 microV of b-wave under light adaptation; 117 +/- 44 microV of b-wave after 1 min dark adaptation; 59 +/- 18 microV of a-wave and 140 +/- 42 microV of b-wave after 5 min dark adaptation), except in a-wave after 1 min dark adaptation (39 +/- 13 microV in tiletamine-zolazepam and 34 +/- 17 microV 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.