The influence of early diabetes on the pattern electroretinogram.

Pattern electroretinogram response and contrast sensitivity were evaluated in two groups of diabetic patients by means of psychophysical and electrophysiological methods. The first group consisted of subjects suffering from diabetic retinopathy in various stages of evolution; the second was composed of diabetic patients with no fundus alterations and with good visual acuity. In both groups of patients, when the pattern electroretinogram was altered, contrast sensitivity was also abnormal.