Gyrate atrophy of the choroid and retina: ERG of the neural retina and the pigment epithelium.

The function of the neural retina and the pigment epithelium in 10 patients with gyrate atrophy was examined by the conventional alternating current electroretinogram and by direct current electroretinography to study the c-wave. The a- and b-wave responses were subnormal in all patients and the ERG was undetectable in patients with an advanced stage of the disease. The c-wave was recordable by the DC ERG from three patients with a less advanced stage of the disease. In one patient the c-wave could be recorded only from the other eye but the a- and b-wave responses were recordable in both his eyes.