Visual evoked potential as an early marker of diabetic retinopathy

Background: Chronic hyperglycemia in diabetes mellitus causes damage to various organs, particularly eyes, kidneys, nerves, heart, and the blood vessels. Visual defects in diabetics occurs due to both vascular and metabolic abnormalities which can affect retina, optic nerve and visual pathway. Change in Visual evoked potential (VEP) response occurs in diabetic patients much earlier than development of overt retinopathy and these changes correlate with duration of disease. Aim of this study was to determine the subtle functional changes in the retina of diabetic eye with the help of VEP before diabetic retinopathy sets in. In the current study comparison between amplitudes, latency P100 of VEP in type 2 diabetes mellitus with that of healthy controls was done. Method: Cross sectional study using 100 controls and 100 diabetic patients was carried out in the department of Physiology Deccan college of Medical Sciences, Hyderabad. Statistical analysis was done using SPSS software. Result: Significant association was obtained between duration of diabetes mellitus and P100 latency. Conclusion: VEP can be used as a very useful electrophysiological indicator of early subtle functional changes of retina in diabetes mellitus. Keywords: Diabetes mellitus, Visual evoked potential, P100 latency, P100 amplitude