title: Severity of age-related macular degeneration in 1 eye and the incidence and progression of age-related macular degeneration in the fellow eye: the Beaver Dam Eye Study.
abstract: OBJECTIVE
  Previous studies regarding the severity of age-related macular degeneration (AMD) in 1 eye and its prognostic implications for the fellow eye have focused on the incidence of neovascular AMD in the fellow eye of participants with neovascular AMD in the other eye. It is unclear to what extent the severity of AMD in 1 eye affects the incidence, progression, and regression of AMD in its fellow eye across the entire range of AMD severity.
  
  
  OBJECTIVE
  To investigate the effect of the severity of AMD in 1 eye on the incidence, progression, and regression of AMD in the fellow eye.
  
  
  METHODS
  The Beaver Dam Eye Study is a longitudinal population-based study of age-related eye diseases conducted in the city and township of Beaver Dam, Wisconsin. Examinations were performed every 5 years over a 20-year period (from the baseline examination in 1988-1990 to 2008-2010). Study participants (n = 4379) were 43 to 86 years of age at the baseline examination. At baseline and in up to 4 subsequent examinations, retinal photographs were taken.
  
  
  METHODS
  Incidence, progression, and regression of AMD (assessed by use of the Wisconsin Age-Related Maculopathy Grading System on retinal photographs and adjusted for age, sex, and the Y402H polymorphism in the complement factor H gene on chromosome 1q) and mortality.
  
  
  RESULTS
  More severe AMD in 1 eye was associated with increased incidence of AMD and accelerated progression in its fellow eye (levels 1-2: hazard ratio [HR], 4.90 [95% CI, 4.26-5.63]; levels 2-3: HR, 2.09 [95% CI, 1.42-3.06]; levels 3-4: HR, 2.38 [95% CI, 1.74-3.25]; levels 4-5: HR, 2.46 [95% CI, 1.65-3.66]). Less severe AMD in 1 eye was associated with less progression of AMD in its fellow eye (levels 2-3: HR, 0.42 [95% CI, 0.33-0.55]; levels 3-4: HR, 0.50 [95% CI, 0.34-0.83]). We estimate that 51% of participants who develop any AMD always maintain AMD severity states within 1 step of each other between eyes; 90% of participants stay within 2 steps.
  
  
  CONCLUSIONS
  Using multistate models, we show that AMD severity in 1 eye tracks AMD severity in its fellow eye.
authors.affiliation: Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison2Department of Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Gangnon
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison.
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison.
authors.forename: Barbara E K
authors.initials: BE
authors.lastname: Klein
authors.affiliation: Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio5Department of Genetics and Ophthalmology, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Sudha K
authors.initials: SK
authors.lastname: Iyengar
authors.affiliation: Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio5Department of Genetics and Ophthalmology, Case Western Reserve University, Cleveland, Ohio6Division of Human Genetics, Cincinnati Children's Hospital Medical Ce.
authors.forename: Theru A
authors.initials: TA
authors.lastname: Sivakumaran
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison.
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008266:Macula Lutea / Q000473:pathology*; D008268:Macular Degeneration / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors