Comparative analysis of pattern visual evoked potentials according to the type of diabetes mellitus in patients in different diabetic retinopathy stages

Abstract The aim of this study was to explore and compare the visual analyser (VA) function in patients with type 1 and type 2 diabetes mellitus (DM) in different stages of diabetic retinopathy (DR). A group of 185 people was studied. The patients with DM were 138. They were divided into two main groups: patients without DR and patients with DR. The first group consisted of two subgroups: patients with newly-diagnosed DM and patients with DM duration longer than 1？year. The second main group consisted of patients with DR divided into two subgroups: patients with initial DR and patients with advanced DR. Every group consisted of patients with type 1 and type 2？DM. Controls for the electrophysiological (EF) studies were 47 healthy individuals. The VA function was examined by pattern visual evoked potentials (PVEPs). The main variables that were considered in the results analysis were the latency and amplitude, reflecting the configuration of the wave forms. The results showed that the PVEPs were more affected in patients with type 2？DM in the first three groups. In the group with advanced DR, the EF values were not statistically significantly different between the patients with type 1 and type 2？DM. The results demonstrated that PVEP studies could be used as an objective method for registration of early changes in the VA function as a DM complication and also, to monitor the changes in dynamics, as they are non-invasive, harmless, fast and repeatable