A Shift of the Pupillary Balance Towards the Parasymphathetic System in Migraine Patients

Abstract

To analyze the static and dynamic pupillometrics in migraine patients with aura and compare these parameters to those in age- and sex-matched healthy participants. This cross-sectional study included 34 patients with migraine and 37 healthy participants as a control group. The static pupillometrics consisted of scotopic pupil diameter (PD), mesopic PD, and low and high photopic PD. The dynamic pupillometrics were as follows: the initial diameter, amplitude of pupil contraction, latency of pupil contraction, duration of pupil contraction, velocity of pupil contraction, latency of pupil dilation, duration of pupil dilation, and velocity of pupil dilation. All participants were evaluated during a headache-free period. An automatic quantitative infrared pupillometry system was used to examine the pupillary characteristics of the eyes. The static and dynamic pupillary parameters except the latency of pupil contraction did not significantly differ between the migraine patients during an attack-free period and the healthy participants. The latency of pupil contraction was significantly statistically lower in migraine group than healthy subjects. Also, the scotopic PD differed significantly in the inter-eye comparison within migraine patients (p<0.05). A significant inter-eye difference in scotopic PD values and the lower latency of pupil contraction in migraine patients with aura in the headache-free period might be attributed to a shift of the pupillary balance towards the parasymphathetic system.