Computed tomography assessment of the narrowest bony nasolacrimal canal diameter with and without primary acquired nasolacrimal duct obstruction: a comparative study of the Chinese population.

PURPOSE: To compare the narrowest diameter of the bony nasolacrimal canal (BNLC) in a Chinese population with and without primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

Eighty-one patients with PANDO and forty-two non-PANDO patients underwent computed tomography (CT) covering the full length of their nasolacrimal canals. The narrowest transverse diameters of the BNLC were measured in axial CT images.

RESULTS

The narrowest BNLC diameter was significantly shorter in PANDO patients than non-PANDO patients (4.20 ± 0.87 mm vs. 4.95 ± 0.82 mm, p < 0.001), especially in patients aged 40 years and older (4.20 ± 0.84 mm vs. 5.11 ± 0.83 mm, p < 0.001). When males and females were analyzed separately, the differences between PANDO patients and controls remained significant (4.32 ± 0.82 mm vs. 5.70 ± 0.64 mm, p < 0.001, male; 4.18 ± 0.88 mm vs. 4.74 ± 0.75 mm, p < 0.001, female). Generally, in the Chinese population, males have a larger minimum transverse diameter compared to females (5.70 ± 0.64 mm vs. 4.74 ± 0.75 mm, p < 0.001). Furthermore, the narrowest transverse diameter of the BNLC remarkably increased with age (r = 0.432, p < 0.0001).

CONCLUSIONS

BNLC stenosis may be an important etiological factor for PANDO in the Chinese population.