Does hyperglycaemia have an influence upon colour vision of patients with diabetes mellitus?

It has been suggested that variations found in colour vision upon repeated testing may be due to fluctuations in the plasma glucose level, but the results of studies to date are conflicting. Therefore, the aim of this study was to investigate whether a short-term increase in plasma glucose concentration had an influence on colour vision in patients with non insulin-dependent diabetes mellitus (NIDDM) (n = 16). The colour vision and plasma glucose levels were monitored every 30 min for a total period of 4 h during three test conditions: two when the plasma glucose levels were increased by the administration of glucose, either orally (n = 8) or intravenously (n = 8), and one when the plasma glucose was relatively stable during fasting conditions (n = 8). The results indicate that the colour vision, as assessed by the Desaturated D15, appears to be unaffected by the short-lived increases in plasma glucose concentrations.