title: Visual and ocular changes associated with exposure to two tertiary amines.
abstract: OBJECTIVE
  To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes.
  
  
  METHODS
  Questionnaires, eye examinations (visual acuity, contrast sensitivity at 2.5% and 1.25% contrast, slit lamp biomicroscopy, and pachymetry), and industrial hygiene monitoring for DMIPA and DMAE were performed over a two week period.
  
  
  RESULTS
  Eighty nine per cent of line workers reported having experienced blurry vision while at work in the past 12 months, compared to 12.5% of prime workers. A total of 108 full shift personal breathing zone (PBZ) air samples for the amines were collected. The mean time weighted average (TWA) concentration of DMIPA was significantly higher in the line division than in the prime division, as was the mean TWA concentration for total amines. The mean TWA concentration of DMAE was higher in the prime division than the line division. Higher levels of total amines were associated with increased risk of reporting blurry vision, halo vision, and blue-grey vision. The risk of corneal opacity rose with increasing exposure to total amines. The prevalence of corneal opacity also increased with increasing concentration of total amines. Median corneal thickness increased with increasing grades of corneal opacity. There was a statistically significant relation between total amine concentration and increased risk of reduced bilateral visual acuity and 2.5% contrast sensitivity.
  
  
  CONCLUSIONS
  Exposure to tertiary amines was associated with blurry, halo, and blue-grey vision, corneal opacity, and decrements in visual acuity and contrast sensitivity at 2.5% contrast.
authors.affiliation: Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, 4676 Columbia Parkway, MS R-10, Cincinnati, Ohio 45226-1998, USA.
authors.forename: E H
authors.initials: EH
authors.lastname: Page
authors.forename: C K
authors.initials: CK
authors.lastname: Cook
authors.forename: M A
authors.initials: MA
authors.lastname: Hater
authors.forename: C A
authors.initials: CA
authors.lastname: Mueller
authors.forename: A A
authors.initials: AA
authors.lastname: Grote
authors.forename: V D
authors.initials: VD
authors.lastname: Mortimer
mesh_terms: D000588:Amines / Q000009:adverse effects*; D003318:Corneal Opacity / Q000139:chemically induced*; D006801:Humans; D009784:Occupational Diseases / Q000139:chemically induced*; D016273:Occupational Exposure / Q000009:adverse effects*; D011327:Printing; D012044:Regression Analysis; D014691:Ventilation; D014785:Vision, Ocular / Q000187:drug effects*
chemical_list: D000588:Amines