title: Measurement of lacrimal punctum using spectralis domain anterior optical coherence tomography.
abstract: OBJECTIVE
  Anterior segment optical coherence tomography (AS-OCT) was used to image the lacrimal punctum and establish normal punctal parameters including the tear volume inside the punctum.
  
  
  METHODS
  This study included totally 67 eyes from 38 normal subjects. Punctal parameters and tear meniscus height (TMH) were measured using spectralis OCT anterior-segment scans. Outer punctal diameter (OPD), punctal depth, tear well diameter (TWD), tear well depth, punctal reserve (PR) and lower eyelid TMH were assessed. Authors defined a 'tear well' as a pool of standing tears in the punctum. Punctal reserve was defined as the difference between punctal depth and tear well depth.
  
  
  RESULTS
  Outer punctal diameter was 614.6 ± 195.6 μm, the punctal depth was 545.8 ± 270.1 μm, TWD was 229.9 ± 133.8 μm, the tear well depth was 434.9 ± 247.8 μm, the PR was 110.9 ± 72.9 μm, the PR ratio was 0.20 ± 0.17, and the TMH was 222.9 ± 88.8 μm. The punctal depth decreased significantly according to the patient's age (correlation coefficient = -0.352, respectively).
  
  
  CONCLUSIONS
  AS-OCT is useful for improving anatomical understanding of the lacrimal punctal structure. Quantitative punctum and tear well measurements were correlated with TMH.
authors.affiliation: Department of Ophthalmology, Bundang CHA Hospital, CHA University, College of Medicine, Seongnam, Republic of Korea.
authors.forename: Youngje
authors.initials: Y
authors.lastname: Sung
authors.affiliation: Department of Ophthalmology, Bundang CHA Hospital, CHA University, College of Medicine, Seongnam, Republic of Korea.
authors.forename: Jong Seo
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Bundang CHA Hospital, CHA University, College of Medicine, Seongnam, Republic of Korea.
authors.forename: Helen
authors.initials: H
authors.lastname: Lew
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007765:Lacrimal Apparatus / Q000033:anatomy & histology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013666:Tears / Q000378:metabolism*; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: lacrimal punctum; normal population; optical coherence tomography; tear dynamics