title: Nasolacrimal System Aeration on Computed Tomographic Imaging: Sex and Age Variation.
abstract: OBJECTIVE
  To investigate variation in aeration of the nasolacrimal drainage system between age groups and genders, and to report the reliability of repeated aeration grading and nasolacrimal canal measurements on CT.
  
  
  METHODS
  Retrospective review of CT images from 92 individuals, 60 female and 32 male, was conducted by 3 independent reviewers for the presence of air within the nasolacrimal drainage system. Diameter and area measurements were also obtained at the smallest identifiable portion of the nasolacrimal canal by 2 independent reviewers.
  
  
  RESULTS
  When air is present on CT, it is seen more fully throughout the nasolacrimal system in men as compared to women. Age data demonstrate that patients from the third and fourth decade have significantly more aeration than older patients. Diameter and area of the nasolacrimal duct within the canal at its narrowest point revealed no correlation with sex, age, or nasolacrimal system aeration. Inter-reviewer reliability shows strong repeatability of aeration grading and nasolacrimal duct measurements between multiple reviewers.
  
  
  CONCLUSIONS
  The results suggest CT is reliable and repeatable modality to assess nasolacrimal system aeration and nasolacrimal duct diameter. Decreased aeration of the nasolacrimal system in females and the elderly mirrors epidemiologic trends for those at risk to develop primary acquired nasolacrimal duct obstruction. Variables in nasolacrimal drainage system anatomy, specifically nasolacrimal duct diameter and area, did not vary between sexes or age groups, suggesting aeration may be an overlooked variable in nasolacrimal system function.
authors: *Section Oculofacial Plastic and Reconstructive Surgery, Ohio University/OhioHealth, Columbus, Ohio, U.S.A.; †Department of Medical Education, Mount Carmel Health Systems, Columbus, Ohio, U.S.A.; ‡Department of Ophthalmology, University of Michigan, Ann Arbor, Michigan, U.S.A.; §Department of Biology, Wittenberg University, Springfield, Ohio, U.S.A.; ‖Department of Ophthalmology, William H. Havener Eye Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, U.S.A.; and ¶The Sinus Institute of Ohio, Dublin, Ohio, U.S.A.
authors: Craig N
authors: CN
authors: Czyz
authors: Thomas S
authors: TS
authors: Bacon
authors: Andrew W
authors: AW
authors: Stacey
authors: Eva N
authors: EN
authors: Cahill
authors: Bryan R
authors: BR
authors: Costin
authors: Boris I
authors: BI
authors: Karanfilov
authors: Kenneth V
authors: KV
authors: Cahill
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000388:Air; D005147:Facial Bones / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008443:Maxillary Sinus / Q000000981:diagnostic imaging; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging*; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult