Corneal Potential Maps Measured With Multi-Electrode Electroretinography in Rat Eyes With Experimental Lesions

Abstract

Corneal potential maps obtained in response to full-field flash stimuli are altered in eyes with scotomas in the central and far-peripheral retina. The meERG approach yields useful spatial information following a single brief flash, analogous to body-surface potential maps used to evaluate heart and brain.

Soft transparent graphene contact lens electrodes for conformal full-cornea recording of electroretinogram

“…The soft graphene electrodes can form tight interface with the cornea with much thinner tear film compared to stiff electrodes, this can be an important factor contributing to the large ERG potential difference. In addition, the more homogeneous retinal illumination enabled by transparent graphene electrode arrays compared to opaque metal-based electrodes used in previous studies 35 , 38 , 43 may also play a role in yielding the different spatial profile of ERG potential. For future work, the development of high-density 2D graphene multi-electrode array which can robustly and reliably interface with the cornea will enable a full corneal potential mapping, providing means for functional retinal activity imaging.…”

“…By applying multiple microelectrodes at different locations on cornea, localized ERG responses can be mapped across the corneal surface under single full-field light stimulus. This multi-electrode ERG (meERG) recording enables elucidating the relationship between the spatial distribution of corneal potentials and that of retinal activity, and validating bioelectric models of the eye for electrophysiological functional imaging of the retina 35 , 36 . Besides, retinal lesions are known to cause change of the local corneal potentials which makes the meERG recording a potential diagnostic tool for detecting local areas of retinal dysfunction under single full-field stimulus 35 , 37 , 38 .…”

“…This multi-electrode ERG (meERG) recording enables elucidating the relationship between the spatial distribution of corneal potentials and that of retinal activity, and validating bioelectric models of the eye for electrophysiological functional imaging of the retina 35 , 36 . Besides, retinal lesions are known to cause change of the local corneal potentials which makes the meERG recording a potential diagnostic tool for detecting local areas of retinal dysfunction under single full-field stimulus 35 , 37 , 38 . Ideally, the electrodes used in meERG should be optically transparent so that they will not reduce illuminance on retina or affect the uniformity of the full-field illumination across the retina.…”

“…A contact glass fitted with 9 electrodes placed along the same meridian was used to record local ERG responses from humans 43 . By utilizing a poly (methyl methacrylate) (PMMA) contact lens with an array of through-holes which are connected to platinum electrodes on the outer surface of the contact lens, recent work obtained two-dimensional (2D) corneal potential maps in both healthy eyes and eyes with experimental retinal lesions from rats 35 , 38 . We note that the ERG amplitude difference between the central and peripheral cornea observed here is larger than what were reported previously 35 , 37 , 38 , 42 , 43 .…”

Contactless recordings of retinal activity using optically pumped magnetometers

“…Then, it would even be possible to look at the topographical distribution of the signal, e.g. in combination with multifocal ERG stimulation (Derafshi et al, 2017).…”