title: Lens opacities among physicians occupationally exposed to ionizing radiation--a pilot study in Finland.
abstract: OBJECTIVE
  The aim of this study was to estimate the prevalence of lens opacities among physicians occupationally exposed to radiation - overall and by occupational factors - and to assess the feasibility of a large-scale study for risk assessment.
  
  
  METHODS
  Based on a nationwide registry of 1312 physicians, mostly radiologists with occupational exposure to ionizing radiation, 120 subjects were invited to participate, of which 59 (49%) consented. The inclusion criteria included (i) age 45-70 years, (ii) cumulative recorded radiation dose >10 mSv, and (iii) duration of work with dose monitoring >15 years. The participants completed a questionnaire regarding occupational history and other risk factors for lens opacities. A full ophthalmological examination was performed. Lenticular changes were graded using the Lens Opacities Classification System, version II (LOCS II), and the Nidek EAS-1000 Scheimpflug slit-imaging videophotography system.
  
  
  RESULTS
  Lens opacities were detected in 42% [95% confidence interval (95% CI) 29-55] of the 57 physicians without prior cataract surgery. Nuclear opacities were found in 14% (95% CI 6-26), cortical in 7% (95% CI 2-19), and posterior subcapsular in 5% (95% CI 1-15) of the subjects. The prevalence of lens opacities increased with age, smoking, and cumulative recorded radiation dose. After controlling for age, gender, and smoking, the excess odds ratio for any lens opacity was 0.13 (95% CI -0.02-0.28) per 10 mSv of cumulative radiation dose.
  
  
  CONCLUSIONS
  Our preliminary results show cortical and posterior subcapsular lens opacities among physicians exposed to occupational radiation, consistent with recent studies on low dose radiation exposure. A full study with an unexposed reference group for risk estimation is warranted.
authors.affiliation: School of Public Health, FI-33014 University of Tampere, Finland.
authors.forename: Samy
authors.initials: S
authors.lastname: Mrena
authors.forename: Tero
authors.initials: T
authors.lastname: Kivelä
authors.forename: Päivi
authors.initials: P
authors.lastname: Kurttio
authors.forename: Anssi
authors.initials: A
authors.lastname: Auvinen
mesh_terms: D000367:Age Factors; D000368:Aged; D002386:Cataract / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D010820:Physicians / Q000706:statistics & numerical data*; D010865:Pilot Projects; D015995:Prevalence; D011834:Radiation Monitoring; D011839:Radiation, Ionizing; D011871:Radiology / Q000706:statistics & numerical data; D012042:Registries; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D011795:Surveys and Questionnaires