[Electrophysiology in hypovitaminosis A]

Electroretinographic examinations performed according to the international standard were used in two patients with alimentary hypovitaminosis A. In one instance a mentally caused long-term deficiency of dietary vitamin A intake was involved, in the second instance a fistula from the proximal jejunum into the transverse colon. In both instances night blindness was reported. The initial vitamin A values were 1.0 and 0.6 micromol/l resp. and after substitution therapy they rose to 2 micromol/l. While the rod and maximal ERG responses improved gradually, the oscillation potentials remained pathological as regards amplitudes and latencies. We consider them therefore a sensitive indicator of the electric sensitivity of the retina also in other cases of confirmed or suspected vitamin A deficiency. The existence and orientation of our metabolic and gerontological clinic provides adequate opportunities for these investigations.