title: Characterizing the lacrimal punctal region using anterior segment optical coherence tomography.
abstract: OBJECTIVE
  Abnormalities of lacrimal punctum size and morphology probably contribute to excess tearing, with significant effects on quality-of-life for affected individuals. Our current understanding of normal punctal morphology originates from ex vivo studies, which are unlikely to capture the true nature of the living punctum. This study used enhanced depth anterior segment optical coherence tomography (OCT) to give improved characterization and understanding of lacrimal punctal structure.
  
  
  METHODS
  Qualitative and quantitative assessments were performed on spectral domain OCT images collected prospectively from 40 lower puncta of 20 healthy volunteers.
  
  
  RESULTS
  The average external lower lid punctal diameter was 0.646 mm (SD 150 μm) on OCT imaging, measured at the largest diameter, which was in parallel to the mucocutaneous junction. Fifty-five per cent of puncta appeared closed, whilst the eyelids were open. Fluid menisci were visible within 73% of puncta. A postpunctal 'ampulla' was visible within three systems, one of which was imaged through the conjunctival surface. Ampullary dilatation occurred laterally, rather than at the medial wall.
  
  
  CONCLUSIONS
  Optical coherence tomography provides quick and non-invasive assessment of the lacrimal punctum and its neighbouring tissue layers. This assessment of punctal size and morphology has the potential for further investigation of punctal physiology, for aiding diagnosis, and for monitoring the results of treatment. The average external diameter of the punctal opening measured in this study is greater than that recorded in anatomical textbooks.
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, London, UK.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Timlin
authors.affiliation: NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Pearse A
authors.initials: PA
authors.lastname: Keane
authors.affiliation: NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Day
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, London, UK.
authors.forename: Tahrina
authors.initials: T
authors.lastname: Salam
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, London, UK.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Abdullah
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, London, UK.|NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Geoffrey E
authors.initials: GE
authors.lastname: Rose
authors.affiliation: Lacrimal Clinic, Moorfields Eye Hospital, London, UK.|NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Ezra
mesh_terms: D000328:Adult; D005143:Eyelids / Q000033:anatomy & histology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007765:Lacrimal Apparatus / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013666:Tears / Q000502:physiology; D041623:Tomography, Optical Coherence
keywords: ampulla; epiphora; lacrimal punctum; non-invasive; optical coherence tomography