Predisposing factors for primary acquired nasolacrimal duct obstruction

Pathological origin of primary acquired nasolacrimal duct obstruction (PANDO) is considered as inflammation of unknown causes; however, specific predisposing factors have not been fully addressed to date.

In an institutional setting, background factors of 45 patients with PANDO were compared to those in 67 control subjects. The control subjects were persons with senile cataract, representing the non-pathological general population. The evaluated background factors were inflammatory medical histories (infectious conjunctivitis and allergic conjunctivitis and/or rhinitis), previously reported factors (POAG and topical timolol), and a novel factor proposed in the current study (exposure to swimming pool). Data were extracted from the patients through interview based on a standardized questionnaire as well as from their clinical records.

After adjustment for age and gender, a history of infectious conjunctivitis was more common in the PANDO group than in the control group (55.6 % vs 32.8 %, P = 0.0027), and regular attendance to indoor swimming pools was also more common in the PANDO group (33.3 % vs 0 %, P < 0.0001). Furthermore, when age- and gender- matched subjects were selected, a history of conjunctivitis and swimming pool exposure were independently associated with the development of PANDO (P = 0.022 and P < 0.0001 respectively). On the other hand, the frequencies of histories of POAG, topical timolol, and allergic conjunctivitis and/or rhinitis were similar between the two groups.

Histories of infectious conjunctivitis and swimming pool exposure could be associated with the development of PANDO, although the pathogenesis of this condition has been considered as inflammation of unknown causes.