A Study of Visual Evoked Potential for Functional Assessment of Visual Pathway in Ophthalmologically Normal Diabetes Mellitus Patients

Background and aim: Diabetic retinopathy(DR) is one of the most common complications of long-standing diabetes mellitus(DM). Early detection of this complication in the preclinical stages by Visual Evoked Potential (VEP) may help formulate management strategies to preserve Vision. With this background in mind, we conducted a cross-sectional study to measure the VEP of patients with DM.
Materials and methods: The study was conducted on 30 patients with diabetes mellitus(1 & 11) having no neurological or ophthalmological complications attending the diabetic clinic of RG Kar Medical College, Kolkata. Their PR-VEP(Pattern Reversal VEP) was measured in both eyes. Different VEP parameters(P100 & N75 waves) were compared with 30 age and sex-matched healthy controls and were statistically co-related with nerve conduction velocity, duration of diabetes, and Hb1Ac.
Results: The P100 & N75 wave peaks were significantly prolonged in diabetic patients compared to healthy non-diabetic control. Also, this prolongation was significant with the increasing duration of the disease.
Conclusion: Our study demonstrates that VEP prolongation in ophthalmologically normal DM patients may serve as an important screening tool to pick up visual dysfunction in the early stages.