To determine the relationship between the optical density of biofilms on silicone tubes and surgical outcomes.Methods:
A total of 43 silicone tubes from 33 patients with nasolacrimal duct stenosis were enrolled at 6 months after bicanalicular silicone tube intubation. The removed silicone tubes were divided into 2 segments. One segment of silicone tube was cultured while the other segment was used to measure optical density of biofilm. Each segment was divided into 3 pieces according to average normal human nasolacrimal anatomy. The first piece was located from puncta to lacrimal sac. The second piece was inside the nasolacrimal duct. The third piece was in the nasal cavity. Surgical outcome was evaluated at postoperative 12 months based on Munk score and fluorescein dye disappearance test.Results:
A total of 31 (72.1%) patients were surgically successful while 12 (27.9%) patients had surgical failure with persistent epiphora. In the second piece of silicone tube, the mean optical density of biofilm was 0.2654 nm in the surgical success group and 0.4472 nm in the surgical failure group. These results showed statistically significant (P < 0.01) difference. The most frequently isolated organism was Staphylococcus aureus in the surgical success group (7 of 31 patients, 22.6%). It was Pseudomonas aeruginosa in the surgical failure group (6 of 12 patients, 50%).Conclusion:
This is the first study that determines the relationship between biofilm on silicone tube and surgical outcome. Biofilm formed on silicone tubes in nasolacrimal duct might cause surgical failure.