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Updated: May 7, 2026

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation
Published on: November 26, 2019
A diagnostic challenge: dilated pupil
Hale Z Batur Caglayan1, Ilksen A Colpak, Tulay Kansu
1aDepartment of Neurology, Faculty of Medicine, Gazi University bDepartment of Neurology, Neuro-Ophthalmology Unit, Institute of Neurological Sciences, Hacettepe University, Ankara, Turkey cDepartment of Neurology, Faculty of Medicine, Neuro-ophthalmology Unit, Hacettepe University, Ankara, Turkey.
Purpose Of Review:
Dilated pupil is a diagnostic challenge encountered by neurologists and ophthalmologists. The aim of this review is to provide an overview of the current data and guidelines concerning dilated pupils.
Recent Findings:
The majority of recent reports on dilated pupils are indicative of several medical conditions that require evaluation. The topical synthetic parasympatholytic agents; local contamination of antihistamines with their antimuscarinic effects; atropine, scopolamine, and tropane alkaloids in all species of Datura plants may produce mydriasis.
Summary:
The causes of pupillary dilatation can be unilateral, bilateral, and transient. The clinical approach to dilated pupils requires stepwise evaluation, and based on the findings, unnecessary and costly procedures can be avoided.

