Case report: Isolated tonic pupil may be sole sign of giant cell arteritis

The authors report the case of a patient with acute, evolving dilation who was diagnosed with biopsy-proven giant cell arteritis. They conclude that the repeated pupil dilation episodes seen in this patient suggest ongoing microvascular insufficiency and discuss mechanisms that may lead to mydriasis. These include parasympathetic dysfunction due to ischemia of the ciliary ganglion and postganglionic parasympathic fibers, and direct iris ischemia.

This paper highlights the fact that an isolated tonic pupil, which is usually a benign syndrome, may be the only sign of giant cell arteritis. In elderly patients with a tonic pupil, GCA symptoms should be questioned. 

Financial Disclosures
Dr. Vaphiades has no financial interests to disclose.