Abstract
Purpose :
Electroretinogram (ERG) testing is traditionally recorded using corneal electrodes, which can be difficult for some to tolerate. Recently, a new type of adhesive skin electrode has been introduced which may be better tolerated. We conducted a prospective study of simultaneous ERG recordings using contact lens and adhesive skin electrodes to compare the differences in signal strength.
Methods :
The study was IRB approved. 18 patients were enrolled by one retina specialist at the Icahn School of Medicine at Mount Sinai, referred for ERG testing for multiple clinical indications. Informed consent was obtained from patients or their accompanying parent. ERGs were obtained according to International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Records were recorded simultaneously from both eyes with ERG-jet ® corneal contact lens electrodes and LKC Technologies ® Sensor Strip skin electrodes using multi-channel instrumentation. A-wave and b-wave amplitudes were compared between the two electrode types.
Results :
Waveform morphologies with skin electrodes were similar to those obtained with contact lens electrodes. The range of mean ratio of amplitudes for the right eye skin electrode to right eye contact lens electrode ranged from 0.37 to 0.57, with standard deviation from 0.21 to 0.51. The mean ratio of left eye skin electrode to left eye contact lens electrode amplitudes ranged from 0.29 to 0.49 (std dev 0.17 - 0.63). The grand average of the response amplitude ratios between skin and contact lens electrodes for all test conditions was 0.43 for right eyes and 0.41 for left eyes (std dev 0.26 for right eyes and 0.34 for left eyes). Correlations between amplitude ratios for right and left eyes ranged from 0.0078 to 0.74 for the various stimulus conditions, with an overall correlation of 0.405 for all conditions combined.
Conclusions :
The ERG responses with skin electrodes had smaller amplitudes than with corneal electrodes but were similar in waveform. Amplitudes obtained with skin electrodes are on average about 40% of those obtained with contact lens electrodes, but the variability of the amplitude ratio is substantial, and correlation between right and left eyes is only fair. Skin electrodes may be a useful alternative method of recording ERGs, especially in children and patients less able to tolerate traditional corneal contact-lens electrode ERG testing, particularly if quantitative interpretation is not critical.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.