Evaluation of the Photopic ERG Using Lower Eyelid Electrodes

摘要

The use of corneal contact lens electrodes for recording ERGs is difficult insome patients (children) and impossible in others (hyperbaric patients) due to unusual recording conditions. After reviewing the various published methods already tested, we implemented of technique that employs a lower eyelid electrode. In addition, a 'Ping-Pong ball Ganzfeld' was fabricated to mimic the Ganzfeld dome typically used in clinical laboratories. Three questions were then addressed: (1) the adequacy of the method for acquiring photopic ERGs; (2) the influence of the direction of gaze on ERG parameters; (3) the day-to-day reliability of the method. When ERGs derived from contact lens electrodes were compared with those obtained from lower eyelid electrodes under the same test conditions, it was found that the lower eyelid electrode waveforms were smaller in amplitude but identical in shape to waveform produced by corneal contact lens electrons. Keywords: Electrodes, Ganzfeld, Electrophysiology, Photopic. (jes)