PURPOSE To screen for diabetic autonomic neuropathy of the pupil using 0.5% apraclonidine and 0.1% pilocarpine and to evaluate the early diagnostic value of this pharmacologic pupillary test by assessing the relationship between pupillary and cardiovascular autonomic neuropathies. METHODS A total of 22 diabetic patients were recruited. Baseline pupillary diameter (PD) and the difference in PD...

Pupil diameter was monitored during picture viewing to assess effects of hedonic valence and emotional arousal on pupillary responses. Autonomic activity (heart rate and skin conductance) was concurrently measured to determine whether pupillary changes are mediated by parasympathetic or sympathetic activation. Following an initial light reflex, pupillary changes were larger when viewing emotion...

The optimal conditions for recording focal pupillary light responses with a multifocal stimulation technique were determined, and the technique was applied to normal subjects and patients with visual field defects. Thirty-seven hexagonal stimuli were presented on a TV monitor with a visual field of 40 degrees diameter under a constant background illumination. Using a slow (4.7 Hz) m-sequence, r...

In addition to its centrally mediated hypotensive action, clonidine causes a decrease in intraocular pressure associated with a long-lasting mydriasis. The present study was conducted to determine to what extent this drug-induced pupillary dilation is of central or peripheral origin. Pupil size was observed in cats anesthetized with pentobarbital. Clonidine (1 to 100 mug per kilogram, intraveno...

The pupil controls the amount of light entering the eye. We have examined both the time course for the development of the light reflex and pupil diameter before and after this event in 50 neonates. The pupillary light reflex was absent in all neonates of less than 30 weeks' gestational age, it gradually developed from this age and by 35 weeks it was present in all. Several possible mechanisms t...

Previous studies have shown that increases in pupil size are correlated with increasing cognitive processing demands. Our aim was to confirm whether these findings could be replicated with new portable and less obtrusive eye-tracking technology. We assessed the percentage change of pupillary diameter from baseline as eight subjects completed a series of randomly ordered arithmetic problems of v...

Objective: To investigate the additive influence of peripheral stimuli, we examined accommodative and pupillary response for a fixation target with peripheral stimuli of different luminance at various distances. Methods: The refractive error and size of pupil diameter were measured monocularly by an autorefkeratometer, looking at a central target of 1 degree of arc at a distance of 100 cm throu...