Dynamic pupillometry as an autonomic testing tool.

Objective: To determine normal values for pupillometry indices in healthy control subjects and to examine these indices in patients with autonomic dysfunction and healthy controls.

Methods: Infrared video pupillometry was used to investigate the pupil response to a brief light flash in 79 healthy controls, 28 patients with normal autonomic function (composite autonomic severity score, CASS < 2), and 26 patients with moderate to severe autonomic failure (CASS > 4) seen in our autonomic laboratory from January 2008 to June 2011. In six subjects, we examined the effects of varying light stimulus intensity and light stimulus duration.