Predisposing factors for primary acquired nasolacrimal duct obstruction.

BACKGROUND: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.