title: Alteration of tear mucin 5AC in office workers using visual display terminals: The Osaka Study.
abstract: OBJECTIVE
  There are limited reports on the relationship between mucin 5AC (MUC5AC) concentrations in tears, working hours, and the frequency of ocular symptoms in visual display terminal (VDT) users. This investigation evaluated these relationships among patients with dry eye disease (DED) and individuals serving as controls.
  
  
  OBJECTIVE
  To determine the relationship between MUC5AC concentration in the tears of VDT users based on the diagnosis of DED and frequency of ocular symptoms.
  
  
  METHODS
  An institutional, cross-sectional study was conducted. Participants included 96 young and middle-aged Japanese office workers. Both eyes of 96 volunteers (60 men and 36 women) were studied. Participants working in a company that used VDTs completed questionnaires about their working hours and the frequency of ocular symptoms. Dry eye disease was diagnosed as definite or probable, or it was not present. Tear fluid was collected from the inferior fornix after instillation of 50 μL of sterilized saline. The MUC5AC concentration was normalized to tear protein content and expressed as MUC5AC (nanograms) per tear protein (milligrams). The differences in MUC5AC concentration between DED groups, between VDT working hours (short, intermediate, and long), and between symptomatic and asymptomatic groups were evaluated with 95% CIs based on nonparametric Hodges-Lehmann determination.
  
  
  METHODS
  Ocular surface evaluation, prevalence of DED, and MUC5AC concentration.
  
  
  RESULTS
  The prevalence of definite and probable DED was 9% (n = 9) and 57% (n = 55), respectively. The mean MUC5AC concentration was lower in the tears of VDT users with definite DED than in those with no DED (P = .02; Hodges-Lehmann estimator, -2.17; 95% CI, -4.67 to -0.30). The mean MUC5AC concentration in tears was lower in the group that worked longer hours than in the group that worked shorter hours (P = .049; estimated difference, -1.65; 95% CI, -3.12 to 0.00). Furthermore, MUC5AC concentration was lower in participants with symptomatic eye strain than in asymptomatic individuals (P = .001; estimated difference, -1.71; 95% CI, -2.86 to -0.63).
  
  
  CONCLUSIONS
  The data obtained in the present study suggest that office workers with prolonged VDT use, as well as those with an increased frequency of eye strain, have a low MUC5AC concentration in their tears. Furthermore, MUC5AC concentration in the tears of patients with DED may be lower than that in individuals without DED.
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Uchino
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan2Ryogoku Eye Clinic, Tokyo, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Uchino
authors.affiliation: Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Yokoi
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Murat
authors.initials: M
authors.lastname: Dogru
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Motoko
authors.initials: M
authors.lastname: Kawashima
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Okada
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan4Santen Pharmaceutical Co, Ltd, Osaka, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Inaba
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan4Santen Pharmaceutical Co, Ltd, Osaka, Japan.
authors.forename: Shusaku
authors.initials: S
authors.lastname: Tamaki
authors.affiliation: Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Aoi
authors.initials: A
authors.lastname: Komuro
authors.affiliation: Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sonomura
authors.affiliation: Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kato
authors.affiliation: Schepens Eye Research Institute and Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Pablo
authors.initials: P
authors.lastname: Argüeso
authors.affiliation: Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kinoshita
authors.affiliation: Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsubota
mesh_terms: D000328:Adult; D016288:Computer Terminals; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC / Q000032:analysis*; D009784:Occupational Diseases / Q000209:etiology*; D013666:Tears / Q000737:chemistry*
chemical_list: D055271:Mucin 5AC