Investigation of Pupillary Changes After Carotid Endarterectomy and Carotid Stent Placement Using Automated Pupillometry

Introduction: Horner's syndrome has been reported after carotid artery endarterectomy (CEA) and carotid artery stenting (CS). This study evaluates pupillary changes after these procedures using automated pupillometry. Methods: Retrospective analysis from a prospective database of pupillometry readings. Cases (14 patients with CEA/CS) were matched to controls (14 patients without CEA/CS). t test models were constructed to examine pupillary light reflex measures for CEA, CS, and controls. Results: The 28 subjects had a mean age of 70 years, 50% were male, and 96% were Caucasian. There was no significant difference in the mean pupil size, constriction velocity (CV), dilation velocity (DV) between the procedural side compared to the contralateral side. However, the mean DV in the left eye after a left sided procedure among CS patients (.67) was lower than mean DV in left eye among controls (.88; P < .0001) and patients undergoing CEA (1.03; P < .0001). Discussion: CS may result in disruption of the carotid artery plexus and decreased sympathetic response thereby reducing DV in the ipsilateral pupil. In addition, decreased CV can also been seen. Conclusion: The findings confirm and extend those of previous authors suggesting that pupillary changes may be seen after CS and automated handheld pupillometry may aid in the detection of Horner Syndrome.