Clinical Significance of Microbial Growth on the Surfaces of Silicone Tubes Removed From Dacryocystorhinostomy Patients SUNG EUN KIM, SUNG JUN LEE, SANG YEUL LEE, AND JIN SOOK YOON ● PURPOSE: To investigate the bacterial infection of silicone tubes removed from patients who underwent dacryocystorhinostomy (DCR) and assess the correlation between the culture results and postoperative clinical features. ● DESIGN: Retrospective observational case series. ● METHODS: Consecutive epiphora patients who under- went external or endoscopic DCR surgery were re- viewed. The postoperatively removed silicone tubes were cultured. Preoperative canalicular stenosis and nasal septal hypertrophy, postoperative inflammation, mem- branous obstruction of nasal mucosa, and the duration of silicone intubation were reviewed. Correlations between the results of bacterial culture and clinical features were verified. ● RESULTS: A total of 39 silicone tubes removed from 33 patients were cultured: 34 (87.2%) external DCR cases and 5 (12.8%) endoscopic DCR. Culture provided pos- itive results in 37 cases (94.9%). A total of 52 isolates were identified: 73.1% gram-positive bacteria, 23.1% gram-negative bacteria, and 3.8% fungi. Of the gram- positive organisms, 73.9% were Staphylococcus aureus. Most of the gram-negative organisms were Pseudomonas aeruginosa, found in 5 eyes. The time of tube placement was significantly longer in cases with P. aeruginosa than in those with other bacteria (P  .001). The rate of pseudomonas infection was significantly higher in cases with revision than in those without revision (P  .001). Final surgical failure was significantly related with can- alicular stenosis (P  .017), pus discharge at extubation (P < .001), history of endoscopic revision (P  .001), and pseudomonal infection (P  .010). ● CONCLUSIONS: Various bacterial species were cul- tured from removed silicone tubes. Although many of them were normal flora, P. aeruginosa infection showed significant relation with membranous obstruction of na- sal mucosa, prolonged silicone intubation, and surgical failure. (Am J Ophthalmol 2012;153:253–257. © 2012 by Elsevier Inc. All rights reserved.) I NFLAMMATION IS KNOWN TO BE A MAJOR CAUSE OF nasolacrimal duct obstruction, and some investigators have suggested that inflammation and fibrosis may be secondary to coexisting infectious colonization within the lumen of the lacrimal system. 1 Thus, several clinical bacteriologic studies have investigated pathogens involved in dacryocystitis, but the pathogens responsible for post- operative lacrimal duct infection have rarely been studied. After lacrimal surgery, soft tissue infection can result in operative failure, and the use of antibiotics may reduce postoperative infection rates. 2 Thus, it is important to elucidate the pathogens that affect such postoperative infection. This study aimed to identify strains colonizing in sili- cone tubes that were removed from patients after dacryo- cystorhinostomy (DCR) and to examine the association of the culture results with patients’ clinical characteristics and surgical outcomes. METHODS WE REVIEWED CHARTS OF CONSECUTIVE EPIPHORA PA- tients who underwent external or endoscopic DCR surgery at Severance Hospital, Yonsei University College of Medi- cine between January 2007 and March 2010. All patients underwent standard irrigation of the lacrimal system and probing to localize the site of lacrimal obstruction or canalicular stenosis. Nasal endoscopy was performed in all patients to detect the presence of nasal septal or middle turbinate hypertrophy. All patients underwent standard external or endoscopic DCR surgery with silicone intuba- tion. Systemic third-generation cephalosporin was orally administered postoperatively for 5 days. Before tube re- moval, slit-lamp examinations were performed to assess the inflammatory signs and discharge of pus material around the tubes. The tubes were removed from the nasal space with an endoscope after cutting the loop between the upper and lower puncta. All removed silicone tubes were placed in trypticase soy broth (Oxoid Inc, Ottawa, Ontario, Canada) and trans- ported immediately to a microbiology laboratory for pro- Accepted for publication Jun 24, 2011. From the Department of Ophthalmology, Myongji Hospital, Kwan- dong University College of Medicine, Koyang, Korea (S.E.K.); Depart- ment of Ophthalmology, Dongguk University Ilsan Hospital, Dongguk University, Seoul, Korea (S.J.L.); and Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea (S.Y.L., J.S.Y.). Inquiries to Jin Sook Yoon, Department of Ophthalmology, Yonsei University College of Medicine, 134 Shinchondong Seodaemungu, Seoul, Korea, 120-752; e-mail: yoonjs@yuhs.ac © 2012 BY ELSEVIER INC.ALL RIGHTS RESERVED. 0002-9394/$36.00 253 doi:10.1016/j.ajo.2011.06.030