title: Genetic risk of primary open-angle glaucoma. Population-based familial aggregation study.
abstract: OBJECTIVE
  To study familial aggregation of primary open-angle glaucoma in a general population and to determine the absolute and relative risks for first-degree relatives.
  
  
  METHODS
  First-degree relatives of patients with glaucoma (n = 48) and control subjects (n = 155) from the population-based Rotterdam Study underwent a standardized examination, including perimetry.
  
  
  METHODS
  Intraocular pressure, vertical cup-disc ratio; and the presence of glaucoma, defined as a visual field defect with a cup-disc ratio of 0.7 or higher or asymmetry of 0.3 or higher between both eyes.
  
  
  RESULTS
  The prevalence of glaucoma was 10.4% in siblings of patients, 1.1% in offspring of patients, 0.7% in siblings of controls, and 0% in offspring of controls. Life-time risk of elevated intraocular pressure in relatives of patients vs relatives of controls was 42.5% vs 6.7%, of enlarged cup-disc ratio was 62.2% vs 16.6%, and of glaucoma was 22.0% vs 2.3%, yielding a risk ratio for glaucoma of 9.2 (95% confidence interval = 1.2-73.9). The population-attributable risk of glaucoma was 16.4%.
  
  
  CONCLUSIONS
  In a general population, relatives of patients with glaucoma have a strongly increased risk of glaucoma. Enlarged cup-disc ratio, not intraocular pressure, was the earliest and most prominent feature of familial aggregation. Further studies are needed to disentangle the genetic components of the increased familial risk.
authors.affiliation: Department of Epidemiology and Biostatistics, Erasmus University Medical School, Rotterdam, The Netherlands.
authors.forename: R C
authors.initials: RC
authors.lastname: Wolfs
authors.forename: C C
authors.initials: CC
authors.lastname: Klaver
authors.forename: R S
authors.initials: RS
authors.lastname: Ramrattan
authors.forename: C M
authors.initials: CM
authors.lastname: van Duijn
authors.forename: A
authors.initials: A
authors.lastname: Hofman
authors.forename: P T
authors.initials: PT
authors.lastname: de Jong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005828:Genetics, Population; D005902:Glaucoma, Open-Angle / Q000453:epidemiology* / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009679:Nuclear Family; D016017:Odds Ratio; D009898:Optic Disk / Q000473:pathology; D009900:Optic Nerve / Q000473:pathology; D015995:Prevalence; D012307:Risk Factors; D058609:Visual Field Tests; D014794:Visual Fields