title: Movement of the lacrimal canalicular wall under intracanalicular pressure changes observed with dacryoendoscopy.
abstract: BACKGROUND
  Movement of the lacrimal canalicular wall has been speculated to occur during blinking. Movement of the common internal ostium has been observed under nasal endoscopy, and pressure changes in the lacrimal canalicular cavity have been observed with a pressure sensor; however, lacrimal canalicular wall movement under pressure changes has not been observed.
  
  
  OBJECTIVE
  To examine movement of the lacrimal canalicular wall under intracanalicular pressure changes using dacryoendoscopy.
  
  
  METHODS
  The authors examined 20 obstruction-free lacrimal canaliculi in 10 patients. A dacryoendoscope was inserted, and water was poured into the intracanalicular cavity via the dacryoendoscope's water channel. The water was then poured or suctioned to cause positive or negative pressure changes in the intracanalicular cavity, and movement of the lacrimal canalicular wall was examined.
  
  
  RESULTS
  The lacrimal canalicular wall moved flexibly with pressure changes. Under positive pressure, the intracanalicular cavity was dilated; however, it narrowed under negative pressure. The extent of movement was more dramatic in the common canalicular portion than the proximal canalicular portion.
  
  
  CONCLUSIONS
  Intracanalicular pressure changes cause movement of the lacrimal canalicular wall. There was a consistent relationship between intracanalicular cavity changes and pressure changes, possibly contributing to lacrimal drainage of the canaliculus.
authors.affiliation: *Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan; and †Ide Eye Hospital, Kasumicho, Yamagata, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kakizaki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Mito
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001767:Blinking / Q000502:physiology*; D004724:Endoscopy; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000502:physiology; D011312:Pressure