Characteristics of Intranasal Structures for Endonasal Dacryocystorhinostomy in Asians

PURPOSE: To describe the anatomic characteristics of structures adjacent to the lacrimal sac fossa and the standardized osteotomy method for endonasal dacryocystorhinostomy in Asians. DESIGN: Retrospective noncomparative observational case series study. MATERIALS AND METHODS: One hundred fifty-two eyes of 76 patients who had normal orbit computed tomographic scans were enrolled. The relationships of the uncinate process, the operculum of the middle turbinate, and the agger nasi cell to the lacrimal sac fossa were analyzed. Bone thickness and proportion of the frontal process of the maxilla in the lacrimal sac fossa was also evaluated. RESULTS: The uncinate process was attached to the lacrimal sac fossa in 152 cases (100%) at the lower level of the fossa. The operculum of the middle turbinate was attached to the lacrimal sac fossa in 142 cases (93.4%), with wide positional variation. The agger nasi cell was adjacent to the lacrimal sac fossa in 118 cases (77.6%). The descent of the operculum of the middle turbinate relative to the lacrimal fossa had a strong correlation with the descent of the agger nasi cell (P < .001). The height and length of the nasal bone had a significant negative correlation with the thickness of the frontal process of the maxillary bone (P < .001). CONCLUSION: The uncinate process, operculum of the middle turbinate, and agger nasi cell should be removed for sufficient osteotomy in a significant portion of Asian patients during dacryocystorhinostomy. A thick frontal process of the maxilla can be anticipated for the patient with a low nasal bridge. Further studies on the variation in intranasal procedures and the success rate of endonasal dacryocystorhinostomy need to be established. (Am J Ophthalmol 2011;152:491-498. (C) 2011 by Elsevier Inc. All rights reserved.)