A DC electroretinography method for the recording of human a-, b- and c-waves

In the clinical ERG the c-wave is not usually recorded due to methodological problems. Because of the potential importance of the c-wave recording in assessing the function of the pigment epithelium in several retinal diseases, we describe a DC ERG method which is convenient for the patient and suitable also for clinical practice. The light stimuli are provided by a Ganzfeld stimulator and the potentials are recorded with a disposable corneal wick electrode. The method allows the recording of the c-wave from co-operative subjects as well as to study the a- and b-wave properties.