Comparing DTL microfiber and Neuroline skin electrode in the Mini Ganzfeld ERG

In infant ERG recordings skin electrodes frequently result in a better compliance. In order to assess the quality of such recordings, we compared the recording characteristics of DTL microfiber and Neuroline surface electrodes using a modified ISCEV protocol in the Mini Ganzfeld ERG.

A prospective cohort study on healthy adult subjects was conducted at the Department of Ophthalmology, University of Basel, Switzerland. Thirty healthy volunteers were tested. The microfiber electrode (DTL Plus Electrode) was placed across the cornea, above the lower eyelid. The Neuroline skin electrode was placed on the surface of the lower lid on the opposite eye. The eye on which each electrode type was placed was randomised. Amplitudes of the rod, standard combined, standard flash cone, light-adapted 3.0 Hz flicker and red cone responses were analysed, as well as their respective implicit times.

Both electrode recordings showed the same waveform characteristics. Responses with the Neuroline electrode were significantly weaker than those from the DTL electrode. Amplitudes of the rod, standard combined, standard flash cone, light-adapted 3.0 Hz flicker and red cone responses were up to four times larger when recorded with the DTL electrode (p < 0.005, ANOVA). Implicit times of the red cone ERGs were slightly faster for the Neuroline skin electrode recordings (p ≤ 0.039).

Comparison of full-field ERG recordings with microfiber DTL and Neuroline skin electrodes showed that DTL electrodes produce larger ERGs. Hence, we provide evidence that both electrode types allow successful full-field ERG recording, although separate normative data for both electrodes are necessary.