Transretinal electrical stimulation by an intrascleral multichannel electrode array in rabbit eyes

Area of Science:

• Ophthalmology
• Neuroscience
• Biomedical Engineering

Background:

• Suprachoroidal transretinal stimulation (STS) is a novel electrical retinal stimulation method.
• Previous studies demonstrated STS efficacy in eliciting electrically evoked cortical potentials (EEPs) in rats.
• Safety and feasibility in medium-sized animals are crucial before human trials.

Purpose of the Study:

• To evaluate the safety and efficacy of surgical implantation of a multichannel electrode array for STS in rabbits.
• To determine the feasibility of eliciting EEPs using STS in a rabbit model.
• To assess potential retinal damage following STS.

Main Methods:

• Acute experiments were performed on six rabbits.
• An eight-electrode gold microelectrode array was implanted into a scleral pocket.
• Cortical responses were recorded following electrical stimulation, and histological examination was conducted.

Main Results:

• Surgical implantation procedures were completed without significant complications.
• EEPs were successfully elicited from all stimulated electrodes.
• Histological analysis revealed no retinal damage at the light microscope level with the tested electrical parameters.

Conclusions:

• The intrascleral microelectrode array technique for STS is safe in rabbit eyes.
• EEPs were elicited using current densities that did not cause tissue damage.
• STS via intrascleral multichannel electrodes represents a feasible approach for retinal stimulation.