In the present study, we cultured specimens and evaluated the types of bacteria existing at the stent and their antibiotic sensitivities from removed nasolacrimal polyurethane stents (Song's stents) due to recurrent inflammation or Song's stent obstruction after placement of Song's stents without fluoroscopic guidance for the treatment of obstructed nasolacrimal ducts.

In 11 eyes of 11 patients who received Song's stent intubation to resolve nasolacrimal duct obstruction, the Song's stents were removed due to either recurred symptoms, signs of chronic dacryocystitis, or tube obstruction. Song's stents were cultured to identify bacteria and tested for their antibiotic sensitivity.

The Song's stent removal was from 3 years 7 months to 17 years 1 month after intubation, thus the average duration was 10 years. The species of cultured bacteria were Pseudomonas in 7 eyes, Staphylococcus aureus in 2 eyes, and Stenotrophomonas maltophilia in 2 eyes. In antibiotics sensitivity tests, 5 of 7 eyes with Pseudomonas were resistant to trimethoprime/sulfamethoxazole (Bactrim®, Roche, Basel, Switzerland) and 2 eyes with Staphylococcus aureus were resistant to penicillin. Ten eyes underwent silicone tube intubation simultaneously during Song's stent removal and 1 eye underwent Song's stent removal only.

The most common bacteriological etiology of Song's stent obstruction or recurrent inflammation is Pseudomonas species. The use of efficient antibiotics is necessary to avoid antibiotic intolerance and simultaneous silicone tube intubation during Song's stent removal and is essential for the management of epiphora.