title: Comparison of scanning electron microscopy findings regarding biofilm colonization with microbiological results in nasolacrimal stents for external, endoscopic and transcanalicular dacryocystorhinostomy.
abstract: OBJECTIVE
  To compare bacterial biofilm colonization in lacrimal stents following external dacryocystorhinostomy (EX-DCR), endoscopic dacryocystorhinostomy (EN-DCR), and transcanalicular dacryocystorhinostomy (TC-DCR) with multidiode laser.
  
  
  METHODS
  This prospective study included 30 consecutive patients with nasolacrimal duct obstruction who underwent EXT-, EN-, or TC-DCR. Thirty removed lacrimal stent fragments and conjunctival samples were cultured. The lacrimal stent biofilms were examined by scanning electron microscopy (SEM).
  
  
  RESULTS
  Eleven (36.7%) of the 30 lacrimal stent cultures were positive for aerobic bacteria (most commonly Staphylococcus epidermidis and Pseudomonas aeruginosa). However anaerobic bacteria and fungi were not identified in the lacrimal stent cultures. Twenty-seven (90%) patients had biofilm-positive lacrimal stents. The conjunctival culture positivity after the DCR, biofilm positivity on stents, the grade of biofilm colonization, and the presence of mucus and coccoid and rod-shaped organisms did not significantly differ between any of the groups (P>0.05). However, a significant difference was found when the SEM results were compared to the results of the lacrimal stent and conjunctival cultures (P<0.001).
  
  
  CONCLUSIONS
  Type of dacryocystorhinostomy (DCR) surgery did not affect the biofilm colonization of the lacrimal stents. SEM also appears to be more precise than microbiological culture for evaluating the presence of biofilms on lacrimal stents.
authors: Department of Ophthalmology, Bagcilar Education and Research Hospital, Istanbul 34200, Turkey.
authors: Melike
authors: M
authors: Balikoglu-Yilmaz
authors: Department of Ophthalmology, Bagcilar Education and Research Hospital, Istanbul 34200, Turkey.
authors: Tolga
authors: T
authors: Yilmaz
authors: Department of Histology&Embryology, Marmara University, Faculty of Medicine, Istanbul 34854, Turkey.
authors: Sule
authors: S
authors: Cetinel
authors: Department of Otorhinolaryngology, Bagcilar Education and Research Hospital, Istanbul 34200, Turkey.
authors: Umit
authors: U
authors: Taskin
authors: Department of Microbiology and Clinical Microbiology, Bagcilar Education and Research Hospital, Istanbul 34200, Turkey.
authors: Ayse
authors: A
authors: Banu Esen
authors: Department of Ophthalmology, Bagcilar Education and Research Hospital, Istanbul 34200, Turkey.
authors: Muhittin
authors: M
authors: Taskapili
authors: Department of Biostatistics and Medical Informatics, Ege University, Faculty of Medicine, Izmir 35100, Turkey.
authors: Timur
authors: T
authors: Kose
keywords: biofilms; dacryocystitis; epiphora; nasolacrimal duct obstruction; scanning electron microscopy