title: Identification of retained intracanalicular plugs with ultrasound biomicroscopy.
abstract: BACKGROUND
  Punctal plugs may be associated with complications, the most common being secondary epiphora due to canalicular obstruction. Simple lacrimal irrigation will diagnose an obstruction within the canaliculus but will not determine whether the plug is still present at the site of the obstruction. We performed a study to determine the feasibility of imaging retained intracanalicular plugs with ultrasound biomicroscopy (UBM).
  
  
  METHODS
  We performed in vitro evaluation of an EagleVision punctal plug and a Herrick intracanalicular plug to obtain information about the UBM characteristics of the two plugs. We then performed UBM in two patients with suspected intracanalicular plugs, one with prolapse of an EagleVision punctal plug into the canaliculus and one with bilateral epiphora secondary to inserted intracanalicular Herrick plugs.
  
  
  RESULTS
  In both cases, UBM enabled location of the plugs within the canalicular system at the level of obstruction.
  
  
  CONCLUSIONS
  UBM is a useful diagnostic tool in determining the presence and location of a presumed retained intracanalicular plug, either placed directly within the canaliculus or prolapsed into the canaliculus from a punctal position.
authors.affiliation: Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ont. jhurwitz@mtsinai.on.ca
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Hurwitz
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Pavlin
authors.forename: El-Karim
authors.initials: el-K
authors.lastname: Rhemtulla
mesh_terms: D000368:Aged; D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000601:surgery; D005129:Eye Foreign Bodies / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007766:Lacrimal Apparatus Diseases / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011391:Prolapse; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D014463:Ultrasonography