Morphometric evaluation of nasolacrimal duct

Objectives: Obstructions are very commonly seen in nasolacrimal duct before it opens into the inferior nasal meatus. Detailed anatomical knowledge of the nasolacrimal duct is crucial for physicians to understand the etiology of the obstructions, to plan ideal management option and to reduce unexpected iatrogenic injuries during surgeries. The aim of this study was to investigate morphometric properties of the nasolacrimal duct on computed tomography images. Methods: Three-dimensional computed tomography (3D-CT) of 142 adults (65 females, 77 males) were retrospectively evaluated. Antero-posterior cranial diameter, antero-posterior and transverse diameters and vertical angle of the nasolacrimal duct, distance between distal end of the nasolacrimal duct to anterior surface of the maxilla were measured and the differences evaluated statistically between right and left sides and among females and males and among different ages. All measurements were done using Osirix-Lite version 9 software. Results: None of the morphometric parameters of the nasolacrimal duct showed significant differences between right and left sides. Antero-posterior cranium and transverse diameter of the nasolacrimal duct were longer in men than women. Conclusion: Determining to morphometric properties of the nasolacrimal canal has advantages for understanding the etiology of the NLD obstructions, deciding the ideal surgical technique and reducing to unexpected injuries during surgeries related with this region.