Zinc deficiency and photoreceptor dysfunction in chronic liver disease.

1. In nine patients with chronic liver disease photoreceptor function was tested, by measurement of the B-wave amplitude of dark adaptation by electroretinography, and the leucocyte content and plasma concentration of zinc were determined. 2. Four of the patients were leucocyte zinc-depleted and had impaired photoreceptor function, but this was normal in the five with normal leucocyte zinc content.