Factors affecting perceptual thresholds in a suprachoroidal retinal prosthesis.

摘要: PURPOSE The suprachoroidal location for a retinal prosthesis provides advantages over other locations in terms of simplified surgical procedure and potentially more stable electrode-neural interface. aim this study was to assess the factors affecting perceptual thresholds, optimize stimulus parameters achieve lowest thresholds patients implanted with prosthesis. METHODS Three profound vision loss from retinitis pigmentosa were array. Perceptual measured on individual electrodes analyzed as function (return configuration, pulse polarity, width, interphase gap, rate), electrode (area number ganged electrodes), clinical (retinal thickness electrode-retina distance) parameters. RESULTS A total 92.8% 904 measurements made up 680 days post implantation yielded (range, 44-436 nanocoulombs [nC]) below safe charge limit. Thresholds found vary between individuals depend significantly distance, negligibly thickness, not area or electrodes. Lowest achieved when using monopolar return, anodic-first short widths (100 μs) combined long gaps (500 μs), high stimulation rates (≥400 pulses per second [pps]). CONCLUSIONS With stimulation, return are most efficacious. To enable rates, an appropriate combination width gap must be chosen ensure low voltages. Electrode-retina distance needs monitored carefully owing its influence thresholds. These results inform implantable stimulator specifications (ClinicalTrials.gov number, NCT01603576.).