title: Punctal and canalicular anatomy: implications for canalicular occlusion in severe dry eye.
abstract: OBJECTIVE
  To characterize the microscopic anatomy of the lacrimal punctum and canaliculi in relation to the tarsal plate, muscle of Riolan, and Horner muscle; and to report a novel technique to excise the horizontal canaliculus in severe dry eye patients.
  
  
  METHODS
  Observational anatomic study and a retrospective case series.
  
  
  METHODS
  The microscopic anatomy was studied in 86 eyelids of 25 cadavers (age range: 45-96 years, mean: 79.5 years). Surgery was performed on 18 canaliculi of 7 patients with dry eyes (age range: 37-69 years, mean: 59.9 years). In the microscopic study, 32 eyelids were incised sagittally, 38 eyelids were incised horizontally (1 mm from the eyelid margin), and 16 eyelids were incised parallel to the tarsal plate. All specimens were stained with Masson trichrome. In the surgical group, probe-guided horizontal canalicular excision with incision of the Horner muscle to the lateral edge of the lacrimal caruncle was performed. Both canalicular stumps were cauterized.
  
  
  RESULTS
  In the microscopic anatomic study, the punctum and the vertical canaliculus were part of the tarsal plate with the muscle of Riolan, whereas the horizontal canaliculus was surrounded by the Horner muscle. In the surgical group, all the operated canaliculi were completely occluded without recanalization 12 months postoperatively. No complications were recorded.
  
  
  CONCLUSIONS
  Based on microscopic anatomic findings that the lacrimal punctum and the vertical canaliculus are part of the tarsal plate, and that the horizontal canaliculus is surrounded by the Horner muscle, excision of the horizontal canaliculus may be an effective technique to treat patients with severe dry eyes.
authors: Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan. cosme@d1.dion.ne.jp
authors: Hirohiko
authors: H
authors: Kakizaki
authors: Yasuhiro
authors: Y
authors: Takahashi
authors: Masayoshi
authors: M
authors: Iwaki
authors: Takashi
authors: T
authors: Nakano
authors: Ken
authors: K
authors: Asamoto
authors: Hiroshi
authors: H
authors: Ikeda
authors: Eiki
authors: E
authors: Goto
authors: Dinesh
authors: D
authors: Selva
authors: Igal
authors: I
authors: Leibovitch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003608:Dacryocystorhinostomy; D015352:Dry Eye Syndromes / Q000601:surgery*; D005143:Eyelids / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000033:anatomy & histology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D016896:Treatment Outcome