Optical Imaging to Evaluate Retinal Activation by Electrical Currents Using Suprachoroidal-Transretinal Stimulation

Abstract

Reflectance changes after STS were localized to the area around the electrode. The strong correlation between the area of the reflectance changes and the amplitude of the EPs suggested that the reflectance changes reflected the activity of retinal neurons elicited by electrical stimulation.

Comparing retinal reflectance changes elicited by transcorneal electrical retinal stimulation with those of optic chiasma stimulation in cats

“…No RCs were detected at area centralis possibly because the signals elicited by electrical stimulation were weak. 11 The changes in the intrinsic signals elicited by diffuse electrical stimulation using DTL electrodes are also very weak in the foveal area, 12 consistent with our fi ndings.…”

“…The gray-scale values (GSVs) of the RCs are correlated with the amplitude of the electrical evoked potentials (EEPs) recorded at the optic chiasma (OX). 11 These fi ndings suggest that retinal RCs elicited by electrical stimulation may be related to the activation of RGCs. However, it is still not clear which layer of the retina is principally activated by electrical stimulation.…”

Fabrication of Fork-Shaped Retinal Stimulator Integrated with CMOS Microchips for Extension of Viewing Angle

“…The spread of stimulation can be discussed through an estimation of the evoked retina by optical imaging of the fundus. (19,20) Miniaturization of stimulus electrodes should be realized for multifork stimulators to mount a large number of electrodes. Miniaturization of the electrodes can be achieved by surface coating of the electrodes.…”

“…A bipolar electrode for recording was inserted into the optic chiasma and connected to a recorder through a differential amplifier. (19) The timing pulse of stimulation was generated by the control box and was sent to the recorder as a trigger signal to start recording.…”

Spatial characteristics of evoked potentials elicited by a MEMS microelectrode array for suprachoroidal-transretinal stimulation in a rabbit

“…However, previous studies of STS primarily focused on feasibility and safety issues, and rarely stressed the spatial characteristics [6,7,15,[18][19][20][21][22][23][24][25]. STS experiments were conducted in some preliminary studies to show that two different stimulating electrodes with inter-electrode distances varying from 700 μm to 5 mm could induce central visual system responses at two different locations [7,15,18,26].…”