Assessment of Visual Evoked Potential to Detect Visual Pathway Dysfunction in Gestational Diabetes Mellitus: A Longitudinal Case-Control Study With Post-partum Follow-up

Abstract

Background: The increasing prevalence of gestational diabetes mellitus (GDM) during pregnancy has opened the opportunity to study its short-and long-term effects on maternal ophthalmic health. Visual evoked potential (VEP) is a non-invasive electrophysiological test that detects functional disturbances along the visual pathway before the physical signs of diabetic retinopathy (DR) can set in. This longitudinal study is aimed at the assessment of changes in VEP in GDM during different stages of pregnancy and 6-12 weeks after parturition by comparing it with normoglycemic controls.Design and method: Diagnosed cases of GDM were recruited along with normoglycemic controls at 24-28 weeks of gestation. Each participant was required to attend two follow-up appointments at 32-38 weeks of gestation and 6-12 weeks after parturition. A blood sample was taken in a fasting state to record biochemical parameters. VEP was recorded using Neuropack S1 MEB-9400 electrodiagnostic equipment (Nihon Kohden, Tokyo, Japan) in a dark room by providing pattern reversal stimuli to each eye.Results: A total of 29 participants (15 in the control group and 14 in the GDM group) completed the entire study procedure. The observed mean P100 latency of both eyes in the GDM group was recorded longer as compared to that in the control group at baseline and during late pregnancy. Although the mean P100 latency saw a significant decline in postpartum visits as compared to that in late pregnancy, the values were higher than in the control group. P100 latency at baseline correlated significantly to serum advanced glycated end products' (AGE'S) levels in the GDM group. Conclusion:Our study findings reflect that the diagnosis of GDM is associated with significant changes in VEP during and after pregnancy as compared to that of healthy pregnant women.