Static and dynamic pupillary changes reflect autonomic effects of acute sleep deprivation in healthy adults

Aim

To assess the pupillary activity and sympathetic skin responses of acute sleep-deprived participants (≤4 h) by comparing these values with non-sleep-deprived controls (>7 h).

Methods

This study included 39 participants, comprising 23 from the sleep deprivation group and 16 from the healthy control group. Self-reported sleep duration, the Karolinska Sleepiness Scale (KSS), and the Epworth Sleepiness Scale (ESS) were used to evaluate the state of sleepiness. Static and dynamic pupillometry measurements using the Sirius topography device, the amplitude of accommodation using Tonoref III, and sympathetic skin responses quantified via EMG were examined.

Results

The mean scotopic and mesopic pupil diameters were higher in acute sleep-deprived participants compared to controls (6.33 ± 0.59 vs 6.05 ± 0.51, P = 0.030 for scotopic luminance; 5.28 ± 0.69 vs 5.00 ± 0.46, P = 0.047 for mesopic luminance, respectively). In dynamic pupillometry, the speed of pupil dilation in the sleep deprivation group was higher than in the control group (0.22 ± 0.03 vs 0.20 ± 0.03, P = 0.004). The photopic pupil diameter, accommodation amplitude, and sympathetic skin responses were similar between the groups (P > 0.05). While sleep duration was inversely correlated with pupil diameters under all luminances, the ESS score was positively correlated with mesopic and photopic pupil diameters (P < 0.05 for each).

Conclusions

Acute sleep deprivation alters both static and dynamic pupil responses, reflecting autonomic changes, whereas sympathetic skin responses remained unaffected. Even a single day of partial sleep deprivation is capable of impairing pupillary responses.