High-resolution computed tomography assessment of bony nasolacrimal parameters: variations due to age, sex, and facial features.

Purpose: To compare nasolacrimal duct anatomy between gender, age, and facial features, and explore correlations between bony parameters.
Methods: A retrospective case series of patients of four races who had high-resolution computed tomography (CT) between 2004 and 2019 covering the full length of their nasolacrimal ducts in two hospitals in Essex, England. Only normal ducts were included; patients with tearing or radiological abnormalities were excluded. Measurements were taken of the nasolacrimal duct and surrounding anatomy based on measurements found in the existing literature.
Results: More females (n = 114) than males (n = 40) were included. Mean age was slightly older for females (45.7 years) compared to males (42.5). Males have taller noses and wider faces. Nasolacrimal duct calibre correlated positively with age, male gender, and facial width, and negatively with nasal height. There was a tendency for nasolacrimal ducts to be longer in males.
Conclusion: The bony nasolacrimal duct is smaller in younger female patients. Having a taller nose and narrower upper face is also correlated with a smaller calibre duct. Acquired nasolacrimal duct obstruction in patients without these demographics or facial features may be more likely due to secondary causes.