title: Occupational lifting and rhegmatogenous retinal detachment: a follow-up study of Swedish conscripts.
abstract: To investigate the association between occupational lifting and the risk of rhegmatogenous retinal detachment (RRD) using data from a large population of men.
  
  
  
  We used data from a national cohort of 49 321 Swedish men conscripted for compulsory military service in 1969-1970. We collected information on surgically treated RRD from the National Patient Register and we followed up the cohort between 1991 and 2009 at ages 40-60 years. Exposure to occupational lifting was assessed by applying a job exposure matrix to occupational data from the 1990 census. Incidence rate ratios (IRRs) and 95% CIs were estimated through Poisson regression models adjusted by degree of myopia, income and education level.
  
  
  
  We observed 217 cases of RRD in 7 80 166 person-years. In univariate analyses we did not observe an association between occupational lifting and RRD. However, after adjustment for myopia and socioeconomic factors, we found an increased risk of RRD (IRR 2.38, 95% CI 1.15 to 4.93) for subjects in the highest category of exposure compared with those in the lowest one. The incidence rate of RRD among subjects lifting heavy loads at least twice per week, aged between 50 years and 59 years, and affected by severe myopia was as high as 7.9 cases per 1000 person-years, compared with an overall rate of 0.28.
  
  
  
  Our study supports the hypothesis that heavy occupational lifting is a risk factor for RRD. Information on myopia degree and socioeconomic status is necessary when studying the association between occupational lifting and RRD.
authors.affiliation: Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Farioli
authors.affiliation: Department of Public Health, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
authors.forename: David
authors.initials: D
authors.lastname: Kriebel
authors.affiliation: Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Mattioli
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.|Centre for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Kjellberg
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.|Centre for Social Research on Alcohol and Drugs, Stockholm University, Stockholm, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Hemmingsson
mesh_terms: D000328:Adult; D005500:Follow-Up Studies; D006801:Humans; D017770:Lifting / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D009216:Myopia / Q000150:complications; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D016012:Poisson Distribution; D012042:Registries; D012163:Retinal Detachment / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology; D012307:Risk Factors; D012959:Socioeconomic Factors; D013548:Sweden / Q000453:epidemiology
keywords: cohort studies; lifting; rhegmatogenous retinal detachment