title: Assessment of vision-related function in patients with age-related macular degeneration.
abstract: OBJECTIVE
  To investigate the validity of the visual function index (VF-14) in assessing visual function in patients with age-related macular degeneration (AMD).
  
  
  METHODS
  Prospective noncomparative observational case series.
  
  
  METHODS
  One hundred fifty-nine consecutive patients attending a sole practitioner's academic retina-only clinic from May 1998 through August 1998 and from May 1999 through August 1999.
  
  
  METHODS
  Correlations were calculated between the VF-14 scores and the medical outcomes study 36-item short form (SF-36), weighted comorbidity scale, visual acuity and clinical AMD severity (stage), and vision self-assessment scales. Documentation of the severity of macular degeneration was performed by a sole examiner.
  
  
  RESULTS
  There was a moderately strong correlation between visual acuity and trouble with vision (r = 0.51), satisfaction with vision (r = -0.50), and overall quality of vision (r = -0.56). A strong correlation was noted between VF-14 score and patients' self-rating of amount of trouble with vision (r = -0.67), satisfaction with vision (r = 0.62), and overall quality of vision (r = 0.67). In comparison, correlations between SF-36 score and patients' self-rating of amount of trouble with vision, satisfaction with vision, and overall quality of vision ranged from r = 0.37 to r = -0.40. Linear regression analysis for the overall study population indicated that AMD severity was not an independently significant predictor of VF-14 score after adjusting for visual acuity. However, among patients with 20/20 vision in the better eye, AMD severity was an independently significant predictor of VF-14 score after adjusting for visual acuity in the worse eye.
  
  
  CONCLUSIONS
  The VF-14 exhibits a considerable degree of validity as a measure of functional impairment in patients with AMD. Age-related macular degeneration severity was an independently significant predictor of VF-14 score in the group of patients with 20/20 vision in the better eye, but this did not hold true for the overall study population. Age-related macular degeneration is associated with substantial impairment in reported visual function.
authors.affiliation: Division of Vitreo-Retinal Surgery, Department of Ophthalmology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mackenzie
authors.forename: Tom S
authors.initials: TS
authors.lastname: Chang
authors.forename: Ingrid U
authors.initials: IU
authors.lastname: Scott
authors.forename: Mark
authors.initials: M
authors.lastname: Linder
authors.forename: Dawn
authors.initials: D
authors.lastname: Hay
authors.forename: William J
authors.initials: WJ
authors.lastname: Feuer
authors.forename: Keith
authors.initials: K
authors.lastname: Chambers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006302:Health Services Research; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008268:Macular Degeneration; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014787:Vision Tests / Q000295:instrumentation; D014785:Vision, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology