Simple and Efficient: Validation of a Cotton Wick Electrode for Animal Electroretinography

Abstract

Purpose: Electroretinography (ERG) is a widely used technique to test retinal function in humans and animals. Recordings are particularly dependent on the type of electrodes used, with the best electrodes often being expensive and not always easy to use. The need of a simple and effective electrode type has led us to search the efficacy of different types of electrodes used in practice and compare them with the modified cotton wick electrode. Material and Methods: A modified type of electrode made of a cotton wick and impregnated with NaCl is described, and the ERG results were compared with other types of electrodes. Results: Compared with standard metal wire loop electrodes, the cotton wick electrode results in obtaining higher amplitudes, a better inter-eye correlation in the same animal and a better reproducibility of the recordings over time. Conclusion: This cotton electrode is simple to make and easy to place. It provides reliable recordings during the entire life span of the animal and reliable comparisons between contralateral eyes, thus providing a powerful tool for ERG studies.