title: Five-year progression of unilateral age-related macular degeneration to bilateral involvement: the Three Continent AMD Consortium report.
abstract: To assess the 5-year progression from unilateral to bilateral age-related macular degeneration (AMD) and associated risk factors.
  
  
  
  Pooled data analyses of three prospective population-based cohorts, the Blue Mountains Eye Study, Beaver Dam Eye Study and Rotterdam Study.
  
  
  
  Retinal photography and interview with comprehensive questionnaires were conducted at each visit of three studies. AMD was assessed following the modified Wisconsin AMD grading protocol. Progression to bilateral any (early and late) or late AMD was assessed among participants with unilateral involvement only. Factors associated with the progression were assessed using logistic regression models while simultaneously adjusting for other significant risk factors.
  
  
  
  In any 5-year duration, 19-28% of unilateral any AMD cases became bilateral and 27-68% of unilateral late AMD became bilateral. Factors associated with the progression to bilateral involvement of any AMD were age (per year increase, adjusted OR 1.07), carrying risk alleles of thecomplement factor Handage-related maculopathy susceptibility 2genes (compared with none, OR 1.76 for 1 risk allele and OR 3.34 for 2+ risk alleles), smoking (compared with non-smokers, OR 1.64 for past and OR 1.67 for current smokers), and the presence of large drusen area or retinal pigmentary abnormalities in the first eye.
  
  
  
  One in four to one in five unilateral any AMD cases, and up to one in two unilateral late AMD cases, progressed to bilateral in 5 years. Known AMD risk factors, including smoking, are significantly associated with the progression to bilateral involvement.
authors.affiliation: Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Nichole
authors.initials: N
authors.lastname: Joachim
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Johanna Maria
authors.initials: JM
authors.lastname: Colijn
authors.affiliation: Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Annette
authors.initials: A
authors.lastname: Kifley
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Wisconsin, USA.
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Gabriëlle H S
authors.identifier: 0000-0002-6212-9403
authors.initials: GHS
authors.lastname: Buitendijk
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Wisconsin, USA.
authors.forename: Barbara E K
authors.initials: BEK
authors.lastname: Klein
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Wisconsin, USA.
authors.forename: Chelsea E
authors.initials: CE
authors.lastname: Myers
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Wisconsin, USA.
authors.forename: Stacy M
authors.initials: SM
authors.lastname: Meuer
authors.affiliation: Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Ava G
authors.initials: AG
authors.lastname: Tan
authors.affiliation: Centre for Clinical Epidemiology and Biostatistics, and School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Holliday
authors.affiliation: Centre for Clinical Epidemiology and Biostatistics, and School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia.|Department of Medicine, John Hunter Hospital and Hunter Medical Research Institute, Newcastle, New South Wales, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Attia
authors.affiliation: Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Gerald
authors.initials: G
authors.lastname: Liew
authors.affiliation: Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Sudha K
authors.initials: SK
authors.lastname: Iyengar
authors.affiliation: Netherlands Institute of Neuroscience of the Royal Netherlands Academy of Arts and Sciences (KNAW), Departments of Ophthalmology AMC, Amsterdam and LUMC, Leiden, The Netherlands.
authors.forename: Paulus T V M
authors.initials: PTVM
authors.lastname: de Jong
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.|Netherlands Consortium for Healthy Aging, Netherlands Genomics Initiative, The Hague, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Johannes R
authors.initials: JR
authors.lastname: Vingerling
authors.affiliation: Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.|Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Caroline C W
authors.initials: CCW
authors.lastname: Klaver
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Wisconsin, USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.affiliation: Centre for Vision Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Jie Jin
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017242:Complement Factor H / Q000235:genetics; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D060005:Genotyping Techniques; D006801:Humans; D015994:Incidence; D008268:Macular Degeneration / Q000175:diagnosis* / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D010781:Photography; D011446:Prospective Studies; D011506:Proteins / Q000235:genetics; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: C514392:ARMS2 protein, human; C493495:CFH protein, human; D011506:Proteins; D017242:Complement Factor H
keywords: Degeneration; Epidemiology; Macula