title: Characterizing the Occluded Lacrimal Punctum Using Anterior Segment Optical Coherence Tomography.
abstract: Epiphora is sometimes associated with an absent or occluded lacrimal drainage punctum (or puncta). This study uses noninvasive "enhanced depth" anterior segment optical coherence tomography (OCT) to give improved characterization and understanding of absent or fully occluded puncta and the underlying canaliculus.
  
  
  
  Anterior segment spectral domain OCT images were collected prospectively from 9 lower puncta of 6 patients with epiphora and absent or fully occluded puncta, not amenable to dilation in clinic, to see if a canaliculus was visible on OCT imaging below the occluded punctum.
  
  
  
  An epithelial lined canalicular lumen was visible on OCT in 4 lower eyelid puncta from 2 patients and OCT identified 80% (4/5) of the canaliculi that were located on microscope-assisted punctal exploration. These lumens were seen within 580 μm depth from the eyelid margin surface. A half of the eyes in which a canaliculus was identified on OCT (the 2 eyes in a single patient) had resolution of epiphora following punctoplasty, and the other patient was found to have coexisting nasolacrimal duct stenosis and required later dacryocystorhinostomy. The positive predictive value for identifying a canaliculus on lower eyelid punctal exploration in acquired complete punctal occlusion (excluding the congenital case) was 1, with a negative predictive value of 1.
  
  
  
  This study demonstrates that canaliculi can be imaged with OCT where formal access is precluded by an occluded punctum. This noninvasive investigation might help predict the likelihood of successful retrieval of a canaliculus at surgical exploration.
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, and NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Timlin
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, and NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Pearse A
authors.initials: PA
authors.lastname: Keane
authors.forename: Geoffrey E
authors.initials: GE
authors.lastname: Rose
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Ezra
mesh_terms: D000328:Adult; D000368:Aged; D003608:Dacryocystorhinostomy / Q000379:methods*; D005143:Eyelids / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000000981:diagnostic imaging* / Q000601:surgery; D007766:Lacrimal Apparatus Diseases / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*