Correlation Between Pupillary Dynamics and Blood Glucose Concentrations

The relationship between pupillary dynamics and blood glucose levels remains an area of interest in understanding how hyperglycemia or hypoglycemia might impact neurological function. In this study, we investigated the association between blood glucose levels and pupillary response using the PLR-3000 pupillometer and a glucometer. We hypothesized that transient hyperglycemia or transient hypoglycemia would alter pupillary dynamics, particularly by increasing the latency of pupillary constriction, given the adverse effects of chronic hyperglycemia or hypoglycemia on retinal ganglion cells. However, our findings indicate that blood glucose levels do not directly affect pupillary response. These results suggest that pupillary dynamics may serve as a reliable non-invasive biomarker for evaluating neuronal damage influencing pupillary constriction, including optic nerve atrophy and neurodegeneration, without the need to control for blood glucose levels through fasting. This insight is particularly relevant for clinical studies involving patients with neurodegeneration, optic nerve atrophy, and diabetes, such as those with Wolfram syndrome, a rare genetic disorder that encompasses these conditions.