Abstract

Background: Type 2 diabetes mellitus (T2DM) is a metabolic disorder showing an increasing trend with an increase in complications such as diabetic retinopathy (DR), which can cause blindness. Most patients do not notice vision loss early; hence, it is beneficial to have dysfunction of the retina identified. Patients with T2DM and DR have shown abnormalities in visually evoked potentials (VEPs). Objectives: To investigate whether VEPs can be used to detect early changes related to T2DM and DR.
Materials and Methods: A total of 111 patients, of both sexes and aged 40-70 years, were studied as three groups of 37 each, who were, respectively, patients with T2DM, patients with DR, and normal subjects. For all the groups, VEP recording was done using Medicaid Neurostim EP machine, and retinal examination was done using direct ophthalmoscopy. The latency and amplitude of P100 in VEP of both eyes were, respectively, analyzed using analysis of variance and post-hoc test.
Results: Our results showed significantly prolonged P100 latencies of VEPs in T2DM patients and DR patients when compared to controls. However, there was no a significant difference observed in the P100 amplitudes of VEPs in T2DM patients and DR patients when compared to controls. Conclusion: The present study has highlighted the importance of VEP as a valuable non-invasive test to detect early neuronal changes in T2DM patients and can be recommended for monitoring early effects of diabetes on visual function.