Medialization of the lamina papyracea after endoscopic ethmoidectomy: comparison of preprocedure and postprocedure computed tomographic scans.

Objective: The purpose of this article is to report computed tomography demonstration of medial bowing of the lamina papyracea in 5 patients after internal ethmoidectomy. Methods: We identified 5 patients who had apparent medial bowing of the lamina papyracea after functional endoscopic sinus surgery (FESS) and who had preoperative scans available. Preoperative and postoperative scans were reviewed using a 3-dimensional workstation to ensure similar angulation of the slices before measurement. Measurements of the interorbital distance and also the position of the posterior margin of the globe relative to a line connecting the lateral orbital walls were performed. Results: Each of the patients demonstrated a decrease in the interorbital distance on the postoperative scan. Measurement of globe position showed that 9 of the 10 globes lay in a more posterior position within the orbit on postoperative examination. Conclusions: Medial bowing of the lamina papyracea may occur as a result of FESS and may lead to relative enophthalmos in comparison. The incidence of this phenomenon is unknown because most patients are not reimaged after FESS.