Spatiotemporal characteristics of visual cortical responses to transpalpebral electrical stimulation

Transpalpebral electrical stimulation (TpES) has comparable therapeutic efficacy to transcorneal electrical stimulation (TcES) for retinal neurodegenerative disorders. Characterizing TpES-evoked visual cortical responses is critical to expand the clinical application of minimally invasive neuromodulation. We performed intrinsic optical signal imaging in the cat visual cortex to characterize spatiotemporal neurovascular coupling responses to independent-channel TpES, analyzed retinal electric field distribution via a human head computational model, with TcES as a control in both in vivo and simulation experiments. TpES evoked peripheral visual field cortical responses and retinal electric fields consistent with TcES patterns, with similar temporal dynamics. TpES amplitudes were comparable or significantly higher, indicating more efficient visual pathway activation. Our findings provide important evidence supporting the advancement and optimization of non-invasive stimulation techniques for the treatment of retinal neurodegenerative diseases.