Pattern Visual Evoked Potentials as a tool to assess the prognosis in Type 2 Diabetes Mellitus subjects attending a tertiary care hospital

Introduction Type- 2 Diabetes Mellitus (DM) is one of the most serious challenges to healthcare, primarily because of the increase in the prevalence of sedentary life styles and obesity. Neuropathies are the common complications of type 2 DM. Visual Evoked Potentials can be used to evaluate the disturbances in the CNS with a simple, sensitive and noninvasive methodology. Aim To evaluate the conduction in optic pathway in type 2 DM patients and compare with that of healthy controls. Objectives To use VEP as a tool to assess the conduction in the optic nerve in study subjects and controls and to correlate the latency P 100 with glycosalated haemoglobin. Study Design Cross-sectional study. Material and Methods The present study was conducted on the study group of 30 type 2 DM subjects and other group of 30 healthy age and gender matched controls. The patients with reduced visual acuity which was not correctable with lenses and with retinopathy were excluded. VEP was recorded by using pattern reversal stimulation with Neuro Perfect Plus POLYRITE. Statistical Analysis The Data was analysed using student unpaired t test and Pearsons correlation coefficient. Results Our results showed statistically significant prolongation of P100 latencies in diabetic patients and also a significant correlation between the delay in the P100 latency and glycosylated hemoglobin. Discussion Ischemia, reduced protein synthesis, depleted myoinositol, and high sorbitol levels have been demonstrated in patients with diabetes and these may result in nerve fibre loss in the peripheral nerves. Hence, it is possible that the optic nerve fibres may also suffer from these diabetes induced changes. The accumulation of these mediators delays the conduction in the visual pathway, which can be the probable cause of delay in the latencies. VEP is simple, sensitive, non invasive and objective technique for evaluating impulse conduction along the optic pathway (central nervous system). Conclusion The abnormalities in the VEP response occur in diabetic patients before the development of overt retinopathy. So, VEP measurements can be used for the An Initiative of The Tamil Nadu Dr. M.G.R. Medical University University Journal of Pre and Para Clinical Sciences early diagnosis of central neuropathy to offer an early opportunity for proper management and reduce the morbidity of illness.