Visual functional outcomes of cataract surgery in the United States, Canada, Denmark, and Spain: report of the International Cataract Surgery Outcomes Study.

Purpose: 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.

Setting: 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.