To the Editor.—Nasolacrimal duct obstruction caused by endoscopic sinus surgery has recently been described in the ophthalmology literature in three reports containing a total of 12 cases.1-3 Damage to the nasolacrimal duct during endoscopic sinus surgery has been stated to occur as a result of excessive anterior enlargement of the maxillary sinus ostium. This mechanism of injury has been illustrated with artistic drawings1 and cadaver dissection.2
In the past year, we have evaluated five patients with histories of sinusitis who developed lacrimal obstruction after endoscopic sinus surgery. Lacrimal obstruction was diagnosed in all five patients by an oculoplastic surgeon (H.J.G.) on the basis of history and a thorough physical examination that included lacrimal irrigation (Jones II testing). Axial computed tomographic scans were obtained on two of the patients. Each of these two pa
Fig 1.—Bilateral surgical defects in the medial wall of the maxillary sinuses. On