title: The prevalence of age-related macular degeneration in Alzheimer's disease.
abstract: BACKGROUND
  Age-related macular degeneration (AMD) and Alzheimer's disease (AD) share several features, including the presence of extracellular abnormal deposits associated with neuronal degeneration, drusen, and plaques, respectively. Investigation of any association of AMD and specifically AD is worthwhile but has rarely been done.
  
  
  OBJECTIVE
  The aim of this study was to determine the prevalence of AMD in subjects with AD in comparison with an age-matched cognitively normal cohort.
  
  
  METHODS
  Cases were defined as those diagnosed with AD using standardized criteria as part of their clinical care, while controls were cognitively intact individuals aged 65 years or more. Dilated retinal photographs were taken, and a range of potentially confounding factors measured including APOE genotype. AMD features were recorded and AMD grades given.
  
  
  RESULTS
  Data was collected on 322 controls and 258 cases. While AMD was associated with AD, and the proportion of cases of advanced AMD in AD cases was twice that of controls, when corrected the association was lost. AD was associated with age, the presence of an APOE allele, and smoking, while being 'generally unwell recently' was associated with a reduced risk of AD.
  
  
  CONCLUSIONS
  AD and AMD are both associated with age, but our study does not find evidence they are associated with each other. However the retina offers an opportunity to non-invasively image neuronal tissue, and more sophisticated imaging techniques may shed light on ocular biomarkers of AD.
authors.affiliation: Centre for Medical Education, Queen's University of Belfast, Royal Victoria Hospital, Belfast, UK.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Williams
authors.affiliation: Vittorio Silvestri, Central Angiographic Resource Facility, Centre for Experimental Medicine, Institute of Clinical Science A, Queen's University of Belfast, Belfast, UK.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Silvestri
authors.affiliation: Northern Health and Social Care Trust, County Antrim, UK.
authors.forename: David
authors.initials: D
authors.lastname: Craig
authors.affiliation: Queen's University of Belfast, Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Institute of Clinical Sciences - Block A, Royal Victoria Hospital, Belfast, UK.
authors.forename: A Peter
authors.initials: AP
authors.lastname: Passmore
authors.affiliation: Queen's University of Belfast, Centre for Experimental Medicine, Institute of Clinical Science A, Queen's University of Belfast, Belfast, UK.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Silvestri
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000453:epidemiology / Q000235:genetics; D001057:Apolipoproteins E / Q000235:genetics; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000150:complications* / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D008609:Mental Status Schedule; D015995:Prevalence
chemical_list: D001057:Apolipoproteins E
keywords: Alzheimer's disease; amyloid-β; macular degeneration; retinal drusen