Role of VEPs in Early Diagnosis of Central Neuropathy in Type 2 Diabetes Mellitus

To compare the Pattern Reversal Visual Evoked Potentials(PRVEPs) of subjects of Type 2 Diabetes mellitus (Type 2 DM) of varying duaration, with age and sex matched healthy controls.

To document that central neuropathy changes occur earlier than clinically evident retinopathy changes, in subjects having Type 2 DM.

A cross sectional study was done on three study groups selected basing on the inclusion and exclusion criteria. PRVEPs were performed using Viking Select neuro-diagnostic system [Viasys Healthcare, USA].

Group 1 → 30 age and sex matched healthy individuals as controls. Group 2 → 30 subjects having Type-2 DM with a duration of <5 years. Group 3 → 30 subjects having Type-2 DM with a duration of 5–10 years. Data was analyzed and processed using EPI INFO statistical software using Unpaired student t-test (two tailed). The level of significance was taken as p<0.05.

P100 latencies were delayed in subjects with type 2 DM when compared to the controls and the delay was statistically significant. P100 latencies were found to be delayed in some subjects of type 2 DM, even with normal fundoscopy findings.

Therefore we conclude that clinically evident retinal vascular disease in subjects with type 2 diabetes mellitus may be preceded by an increase in visual evoked potential latency in electro physiologic testing.