Intraoperative dilated pupil during nasal polypectomy

In endoscopic sinus surgery, it is often desirable to prepare the nasal mucosa with a nasal decongestant to minimise blood loss and enhance the operative field during surgery. A widely used commercially available preparation for such a purpose is a solution containing 5% Lidocaine Hydrochloride and 0.5% Phenylepherine Hydrochloride. We report a case of a unilateral dilated pupil occurring during nasal polypectomy. A dilated pupil during sinus surgery is associated with an intraorbital injury but many commonly used nasal decongestive agents can also cause mydriasis and this knowledge may prevent some anxiety for the unwary ENT surgeon undertaking sinonasal surgery.