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

Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO)

Primary acquired nasolacrimal duct obstruction, or PANDO, is a common adult lacrimal drainage disorder. The current treatment modality of dacryocystorhinostomy to bypass the obstructed nasolacrimal duct has excellent outcomes. However, the understanding of the disease etiopathogenesis needs to be revisited. There are not many studies that specifically assessed any hypothesis or ones that convincingly put forth the presumed or confirmed interpretations regarding the PANDO pathogenesis or the mechanisms or pathways involved therein. Histopathological evidence points to recurrent inflammation of the nasolacrimal duct, subsequent fibrosis, and the resultant obstruction. The disease etiopathogenesis is considered multifactorial. Several implicated suspects include anatomical narrowing of the bony nasolacrimal duct, vascular factors, local hormonal imbalance, microbial influence, nasal abnormalities, autonomic dysregulation, surfactants, lysosomal dysfunction, gastroesophageal reflux, tear proteins, and deranged local host defenses. The present work reviewed the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO) to gain insights into the present state of the understanding and the high-value translational implications of precisely decoding the disease etiology.

Morphometric differences in normal bony nasolacrimal anatomy: comparison between four ethnic groups

PURPOSE

To compare bony nasolacrimal duct anatomy between ethnic groups.

METHODS

A retrospective observational study of patients of four ethnic groups who had high-resolution CTs 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. South Asian (Indian subcontinent), Afro-Caribbean and European groups were equivocal demographically (n = 25-29, mean age 40-45); however, the Oriental group was fewer in number (n = 13) and slightly older (mean age 51). South Asian and European ducts had no significant differences. Afro-Caribbean ducts were wider and shorter than European. Afro-Caribbean faces are wider and their noses flatter and wider than European. Oriental ducts were wider and longer than European, but Europeans have taller noses.

CONCLUSION

The results from our Oriental group fits with the published data in Orientals. The bony nasolacrimal duct is greater in calibre (inner diameter) if the patient is of Afro-Caribbean or Oriental origin compared to European or South Asian. Acquired nasolacrimal duct obstruction in Afro-Caribbean or Oriental patients may be more likely due to secondary causes.