Abstract
Abstract: :
Purpose: To identify the i-wave of the ERG in albino rabbit. Methods: Four healthy adults New Zealand White rabbits were anesthetized using a unique intramuscular injection of a mixture of metedomidine/ketamine (0.07/10 mg/kg). Mydriasis was maximally induced before ERG recordings. An appropriate contention device was used to keep the head immobile. The use of two active electrodes clipped in sclero-conjunctival area allowed a perfect globe fixation and eyelids opening. Bilateral ERG responses were simultaneously evoked using two photostimulators positioned to achieve full-field conditions. Under photopic conditions (≷ 20 cd.m-2), 30Hz flicker, oscillatory potentials, i-wave and flash ERG were recorded using standard white flashes (2.5 cd.s.m-2). I-wave amplitude and implicit time were measured. Reproducibility of ERGs was tested in 3 occasions with a 6-day interval. Results: In all occasions, in addition to the usual parameters obtained in ERGs, the i-wave was identified in both eyes, with an implicit time of approximately 65 ms, clearly distinct from the a-b-wave complex. Conclusion: The morphology and implicit time are consistent with those of the i-wave described in humans, and presumed to be generated by the retinal ganglion cells and/or optic nerve. If confirmed, this could become an alternative to the pattern-ERG for investigation of ganglion cell and/or optic nerve activities, particularly in laboratory animals.
Keywords: 396 electroretinography: non-clinical • 316 animal model