title: Visual functional outcomes of cataract surgery in the United States, Canada, Denmark, and Spain: report of the International Cataract Surgery Outcomes Study.
abstract: OBJECTIVE
  To compare functional outcomes after cataract surgery performed at 4 sites in 4 countries that have been described as having significant differences in the organization of care and patterns of clinical practice.
  
  
  METHODS
  Multicenter cohort study from the United States, Canada, Denmark, and Spain.
  
  
  METHODS
  Clinical data and patient interview data were collected preoperatively and 4 months postoperatively. Functional outcomes were assessed by the Visual Function Index (VF-14), a self-reported measure of visual function. Scores on the VF-14 range from 0 (maximum impairment) to 100 (no impairment).
  
  
  RESULTS
  Unilateral surgery was performed in 1073 patients. In this subgroup, the odds of achieving an optimal functional outcome (VF-14 score > or =95) were similar among sites after controlling for differences in case mix. Bilateral surgery was performed in 211 patients. A postoperative visual acuity of 0.50 or better in both eyes was reported in 155 patients. However, 37% of these patients reported visual function impairment (VF-14 score <95).
  
  
  CONCLUSIONS
  A previously identified variation in treatment modalities among the 4 sites did not have a significant effect on the odds of achieving an optimal functional outcome. In addition to visual acuity measurements, the VF-14 index provides information on functional outcomes that is useful, especially in studies assessing the benefits of cataract surgery in a public health care setting.
authors.affiliation: University Eye Clinic, Frederiksberg Hospital, Copenhagen, Denmark. jens.c.norregard@fh.hosp.dk
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Norregaard
authors.forename: Peter
authors.initials: P
authors.lastname: Bernth-Petersen
authors.forename: Jordi
authors.initials: J
authors.lastname: Alonso
authors.forename: Tavs Folmer
authors.initials: TF
authors.lastname: Andersen
authors.forename: Gerard F
authors.initials: GF
authors.lastname: Anderson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction; D005060:Europe; D005260:Female; D019538:Health Care Surveys / Q000706:statistics & numerical data; D006801:Humans; D007391:International Cooperation; D008297:Male; D008875:Middle Aged; D009656:North America; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014792:Visual Acuity / Q000502:physiology*