[Multifocal ERG using ERG-jet and Gold Foil electrodes in normal subjects: comparison and reproducibility]

To compare multifocal electroretinogram (mfERG) amplitudes with the Gold Foil electrode and ERG-jet electrode. To study mfERG amplitude changes between two successive records (intraindividual reproducibility).

The right eye of 27 normal subjects was examined. Two mfERG recordings using the 61-hexagon strategy (Vision Monitor, Métrovision, France) were made with both ERG-jet and Gold Foil electrodes. N1 and P1 wave amplitudes were analyzed in the central response and in four concentric rings. Bland and Altman analysis was used for the reproducibility study.

MfERG amplitudes were significantly lower with the Gold Foil electrode, which averaged 72+/-10% of ERG-jet amplitudes. For N1 and P1 waves, the percentage change for the intraindividual reproducibility study was 9.1% and 6.7%, respectively, with the ERG-jet electrode and 18.2% and 13.5%, respectively, with the Gold Foil electrode.

MfERG amplitudes were larger and more reproducible with an ERG-jet electrode than with a Gold Foil electrode. The limits of agreement of each ring can be used in clinical practice to determine whether the variation between two mfERG recordings over time is normal, which could reflect a retinal disorder.