Mydriatic pupil in giant cell arteritis

Area of Science:

• Ophthalmology
• Neurology
• Rheumatology

Background:

• Giant cell arteritis (GCA) is a systemic vasculitis primarily affecting medium and large arteries.
• Ocular manifestations of GCA can lead to irreversible vision loss, making early diagnosis critical.

Observation:

• A patient presented with acute, progressive pupil dilation (mydriasis).
• The pupil exhibited near-light dissociation and denervation hypersensitivity.
• The patient was diagnosed with biopsy-proven giant cell arteritis.

Findings:

• This case documents the temporal progression of mydriasis in GCA.
• Possible mechanisms include parasympathetic dysfunction from ciliary ganglion/nerve ischemia or direct iris ischemia.
• Recurrent pupil dilation suggested persistent microvascular insufficiency.

Implications:

• Mydriasis can be an infrequent but significant sign of GCA.
• Prompt recognition and treatment of GCA are essential to prevent further ischemic events and vision loss.
• This case underscores the need for ophthalmologic evaluation in suspected GCA with pupillary changes.