An updated standard for clinical electroretinography
M. F. Marmor
Department of Ophthalmology, Stanford (Calif) University School of Medicine, USA.
The value of the electroretinogram (ERG) in clinical practice depends in
part on its consistency and the ability to compare results with other
laboratories and the literature. These issues were addressed by the
publication of the International Standard for Clinical Electroretinography
in 1989. This Standard provided technical information and defined a core of
basic test procedures and test responses (Figure) to ensure that ERGs
performed worldwide would be equivalent for clinical and research purposes.
Most major laboratories now subscribe to the tenets of the Standard, and it
should be noted that the Standard does not limit laboratories from doing
additional specialized tests (beyond the recommendations) for either
clinical purposes or research. Since science and medicine are not static,
the original Standard mandated revision every 4 years by the International
Society for Clinical Electrophysiology of Vision. The first revision,
titled "Standard for Clinical Electrophysiology (1994 Update)," has just
been published, and it contains changes and new provisions that should be
reviewed carefully by those who perform ERGs. The major changes and
additions in the updated ERG Standard are as follows.
