The Pupillary Dynamics of Patients with Physiological Anisocoria

Background: To evaluate static pupillometric measurements and making inter-ocular comparative analysis in healthy subjects for demonstrating the prevalance of physiological anisocoria in various lighting conditions and to compare the variations of the dynamic pupillometric measurements of the patients with physiological anisocoria.

Methods: Automatic quantitative pupillometry system was used to measure pupillary diameters in low mesopic (0.1 cd/m), high mesopic (1 cd/m), low photopic (10 cd/m) and high photopic (100 cd/m) conditions. After inter-ocular comparison of these data, the prevalance of physiological anisocoria was detected in four different lighting conditions. The inter-ocular dynamic pupillometric parameters (amplitude, latency, duration and velocity of pupil contraction; latency, duration and velocity of pupil dilation) of these patients were further analysed.

Results: After inter-ocular comparison of pupillary diameters of 195 participants [96 females (49.2%) and 99 males (50.8%)] with a mean age of 38.4 ± 18.9 years (range 7-78 years), six (3.1%) participants under high photopic; 11 (5.6%) participants under low photopic; 25 (12.8%) participants under high mesopic, and 34 (17.4%) participants under low mesopic illumination levels exhibited physiological anisocoria. The mean relative amplitude of anisocoric small pupils' contraction was lower than the mean relative amplitudes of pupil contraction of both isocoric and anisocoric large pupils (p = 0.021, p = 0.035, respectively). The mean velocity of anisocoric small pupils' contraction was lower than the mean velocity of anisocoric large pupils' contraction (p = 0.013).

Conclusions: The mean contraction amplitude and contraction velocity of smaller pupils was lower when compared to fellow larger pupils of anisocoric patients.