Comparisons of the amplitude size and the reproducibility of three different electrodes to record the corneal flash electroretinogram in rodents

To compare corneal electrodes commonly used in rodent eyes for repeat and l eft versus right eye accuracy and variability to record the flash electrore tinogram (ERG). Animals studied were eight C57BL/6 mice and eight rats of t he Wistar strain. Scotopic ERGs were recorded from eyes of dark-adapted ane sthetized rodents to compare a custom-made gold-wire contact lens electrode (CLE), a cotton-wick silver-silver chloride electrode (SCLE), and a coiled stainless steel wire electrode (SSE). Compared to SCLE and SSE, the potent ials recorded by CLE are characterized by significantly larger ERG amplitud es and oscillatory potentials in both rats and mice (p < 0.0001). In analyz ing test-retest data comparing the three different electrodes the coefficie nt of variation was smaller (range, 10.3-15.5%) and the interclass correlat ion coefficient (0.77-0.93) showed a better agreement for the CLE. Recordin g scotopic ERGs with custom-made gold-wire contact lens electrodes records large amplitudes and shows a good reproducibility and reliability to monito r retinal function in rodent eyes.