Evaluation Of The Role Of Visual Evoked Potentials In Detecting Visual Impairment In Type II Diabetes Mellitus

Abstract

Purpose:- : To investigate the visual evoked potentials in Type II diabetic patients in order to determine the alterations, if any, resulting from visual impairment due to diabetes mellitus (DM). Material & Methods:- The study was conducted in the Neurophysiology unit of the Department of Physiology of a rural medical college of Central India. The study population consisted of 30 patients diagnosed with Type II DM and 30 age matched controls after proper screening as per inclusion and exclusion criteria. Both eyes of the two groups of the subjects were included in the study. Design:- Tertiary care rural hospital based, single time assessment, short term observational study. Methodology:- The stimulus configuration consisted of the transient pattern reversal method in which a black and white checker board is generated (full field) on a VEP Monitor by an electronic pattern regenerator inbuilt in an Evoked Potential Recorder. Results:- Mean age of Type 2 diabetic subjects was 58.21 ± 8.17 years and it was 54.48 ± 3.87 years in controls. Except N70 Latency of LE, there was a statistically significant difference between diabetic subjects and controls in terms of all the PRVEP parameters of both the eyes (P<0.001). The pathological VEP was recorded as significant prolongation of P100 latency and significant lower amplitude in diabetic patients compared to control group. A significant intra-ocular difference was observed in 20% cases. The differences between the three groups namely diabetics with diabetic retinopathy (DR), diabetics without DR and controls using One-way ANOVA were statistically significant in terms of P100 and N155 latencies and P100 amplitude (P<0.001), with the exception of N70 latency. Conclusion:- P100 wave latencies were significantly delayed in the diabetic patients compared with the control subjects indicative of functional disturbances in the visual system related to glucose metabolism. Abstract neuropathy associated with DM, it is pertinent to expect dysfunction to occur along the visual pathway right from the retina. 5 Diabetic retinopathy is usually considered to be a disease of retinal blood vessels but is rarely thought of, in a wider sense, as a neurosensory disorder.