Visual evoked potentials in young persons with newly diagnosed diabetes: along-term follow-up

To evaluate the presence of electrophysiological abnormalities in the visua l function of young persons with diabetes, visual evoked potentials were re corded, in basal conditions and after photostress, in 30 patients with newl y diagnosed insulin-dependent diabetes mellitus, Their mean age was 17.6 ye ars (3.6 SD), and their glycosated haemoglobin (HbA1c) was 9.4% (1.6 SD), T hirty healthy age- and sex-matched individuals were evaluated as the contro l group. This study showed that the P100 latency was significantly delayed in patients with diabetes compared with the control group (p<0.01), while t he N75 to P100 amplitude was similar in both groups. These measurements wer e repeated after 6 months, when all participants with diabetes had achieved good metabolic control (HbA1c 7.2% [1.5 SD]). At this second evaluation a complete normalisation of all parameters was observed. These findings sugge st that early functional abnormalities of the optic nerve can be detected a t onset of diabetes, and that glycaemic control reverses these abnormalitie s.