title: Manometric measurement of lacrimal sac pressure after endoscopic and external dacryocystorhinostomy.
abstract: OBJECTIVE
  To evaluate endoscopic and external dacryocystorhinostomy (DCR) using a quantitative, objective functional tool.
  
  
  METHODS
  This study comprised 58 cases divided into 4 groups: healthy controls; patients suffering from epiphora due to nasolacrimal duct (NLD) obstruction; patients who had undergone endoscopic DCR; and patients who had undergone external DCR. The lacrimal sac pressure was measured during blinking, forced blinking and the Valsalva maneuver using a polygraph.
  
  
  RESULTS
  Negative pressure was detected during blinking and forced blinking in all normal subjects and in most patients who had successfully undergone DCR. In contrast, positive pressure was detected in cases with epiphora and patients in whom DCR had failed. Negative pressure was higher after endoscopic than external DCR. During the Valsalva maneuver there were no pressure changes in normal cases and patients with epiphora. In contrast, positive pressure was detected after all of the successful procedures (being higher after external than endoscopic DCR) and in most of the patients in whom external DCR failed.
  
  
  CONCLUSIONS
  In normal subjects, negative pressure is created during blinking. In cases with epiphora due to NLD obstruction, the lacrimal pump is affected but its function is restored after successful DCR. The suction power of the pump mechanism is more effective after endoscopic than external DCR.
authors.affiliation: Department of Otorhinolaryngology, Cairo University, Egypt. rkamel@mednet2.camed.eun.eg
authors.forename: Reda
authors.initials: R
authors.lastname: Kamel
authors.forename: Hany Gamal
authors.initials: HG
authors.lastname: El-Deen
authors.forename: Yehia Salah
authors.initials: YS
authors.lastname: El-Deen
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Hamshary
authors.forename: Atef
authors.initials: A
authors.lastname: Assal
authors.forename: Mohamed
authors.initials: M
authors.lastname: Farid
authors.forename: Ahmed
authors.initials: A
authors.lastname: Sleit
authors.forename: Hany
authors.initials: H
authors.lastname: El-Gamal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D003608:Dacryocystorhinostomy / Q000379:methods*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007765:Lacrimal Apparatus / Q000502:physiology*; D007766:Lacrimal Apparatus Diseases / Q000175:diagnosis / Q000601:surgery; D007767:Lacrimal Duct Obstruction / Q000175:diagnosis; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D011184:Postoperative Period; D011312:Pressure; D011446:Prospective Studies; D012016:Reference Values; D016896:Treatment Outcome