Is general anaesthesia necessary to record reproducible electroretinograms in rabbits?

In toxicity testing of intraocularly applied substances the flash electroretinogram (ERG) serves as an indicator of intact or reduced retinal function in the animal. Insufficiently monitored narcosis may be a source of puzzling ERG results. We performed electroretinography in 25 dark-adapted rabbits without general anaesthesia to evaluate the reproducibility of that method. Two recordings obtained at a mean interval of 26.87 days were compared. The scotopic a- and b-waves showed the same characteristics concerning shape, amplitude and implicit time known from other publications dealing with ERG recordings in narcotised rabbits. No statistically significant difference could be found between the test and retest recordings. It could be demonstrated that narcosis is not necessary for recording of stable and reproducible scotopic ERGs in rabbits.