Skövde Cataract Study : I. Prevalence of Lens Opacities in a Swedish Community

ObjectiveTo study the prevalence of lens opacities in a well-defined Swedish population.DesignPopulation-based cross-sectional study.ParticipantsSeven hundred inhabitants of the town of Skövde, Sweden were randomly selected and invited to an ophthalmologic examination. Invited persons were 70 to 84 years old and were assigned to 1 of 3 age groups: 70 to 74, 75 to 79, or 80 to 84.MethodsAll participants underwent visual acuity (VA) testing using the Early Treatment Diabetic Retinopathy Study acuity chart. Lens opacities were graded using the Lens Opacities Classification System III after pupil dilation. Causes of visual impairment, other than cataract, were identified by thorough ophthalmologic examination.Main Outcome MeasurePrevalence of lens opacities.ResultsFive hundred sixty-five persons underwent a complete examination (participation rate, 80.7%). As expected, the presence of lens opacities increased with age. Using a definition of cataract based on morphologic changes only, prevalences of cataract in one or both eyes were 23.5% for women and 14.0% for men in the entire cohort. If prevalence of previous cataract surgery was included, prevalence rose to 47.9% for women and 27.3% for men. In all age groups, lens opacities were denser and cataract prevalence was higher in women than in men. Consequently, VA was lower in females than in men, when other reasons for visual impairment were excluded.ConclusionsLens opacities were common in the studied age groups and increased with age. In all studied age groups, lens opacities were denser in women than in men.