Infrared pupillography in patients with diabetes mellitus

Abstract

To examine effects of diabetes mellitus on the pupillary light reflex it was analysed using a new compact integrated infrared pupillograph (CIP). PATIENTS AN METHODS: We examined 52 patients with diabetes mellitus and 21 control subjects. The initial pupillary diameter was diminished in the group of the diabetics. This was the only parameter that was significantly diminished in the group of all patients with diabetes mellitus. The maximal constriction velocity, the maximal velocity of the first part of the redilation, the reflex amplitude and the latency time were significantly reduced only in those patients showing also signs of autonomic neuropathy of the cardiovascular system. The amplitude and the velocities however, measured as part of the initial pupillary diameter showed no significant reduction. This leads to a very crucial question when examining the pupillary reflex of diabetics. Which alterations are due to the pathological small pupil and which are directly due to autonomic neuropathy. This study shows that the diminished pupillary diameter after adaptation to the dark is an early sign of autonomic neuropathy; other alterations in the pupillary reflex can be seen after other symptoms of the autonomic neuropathy are shown as well.