Pupillary dysfunction of multiple system atrophy: Dynamic pupillometric findings and clinical correlations

Abstract Introduction Although autonomic dysfunction is the prominent clinical feature in multiple system atrophy (MSA), little is known about the pupillary autonomic aspect of MSA. We aimed to evaluate pupillary autonomic function in MSA patients using dynamic pupillometry, which can quantify the pupillary light reflex. Methods Dynamic pupillometry parameters were compared in 21 MSA patients and 21 healthy controls. Pupillometric parameters were correlated with total Unified Multiple System Atrophy Rating Scale (UMSARS) scores and autonomic symptom severity. Results Average constriction ( p  = 0.034) and dilation ( p  = 0.003) velocities were significantly slowed in MSA patients compared with controls. Total UMSARS correlated with the average constriction (r = −0.527, p  = 0.017) and maximum constriction ( r  = −0.658, p  = 0.003) velocities. Autonomic symptom severity correlated with average constriction ( r  = −0.544, p  = 0.013), maximum constriction ( r  = −0.607, p  = 0.005) and average dilation ( r  = −0.499, p  = 0.025) velocities. Conclusion Dynamic pupillometry may provide useful information about pupillary autonomic dysfunction, which correlated with the clinical severity, in patients with MSA.