Standard ERG equipment can be used to monitor functionality of retinal implants

Identifying whether or not a retinal implant has malfunctioned after implantation is crucial for safety and efficacy testing in preclinical animal studies and clinical testing in human volunteers. Technical failure can lead to charge injection to areas other than the retina leading to a misjudgment of safety considerations or psychophysical results. This study assessed the feasibility of using standard ERG recordings for the detection of failure of a subretinal implant in-situ using a porcine model. Corneally recorded potentials were compared before and after introduction of damage to the implant leading to failure to deliver charges to the retina. The recorded signal decreased by up to 173% following induced damage to the implant. This shows that standard ERG equipment can be used to monitor if a malfunction occurred in animal testing and can also be applicable in clinical trials.