PREVALENCE AND RISK-FACTORS OF LENS OPACITIES IN THE ELDERLY IN FINLAND - A POPULATION-BASED STUDY

Purpose: The distribution and prevalence of lens opacities and Visual impairment caused by cataract were studied in an epidemiologic cross-s ectional population study of inhabitants 70 years of age or older in t hree communities in Oulu County, Finland. Methods: Of the 560 eligible subjects, 500 (89.3%) were examined. The best-corrected visual acuity for distance in both eyes was determined. The diagnosis of lens opaci ties was based on clinical biomicroscopy. The findings were compared w ith standardized photographs of the Lens Opacities Classification Syst em II. Results: One hundred sixty-five (33.0%) persons in the study po pulation had a clear lens in both eyes. Cataract, aphakia, or pseudoph akia was recorded in one or both of the eyes in 64.4% (322 persons) of the participants. The prevalence increased with age from 44.6% of per sons (n = 88) in the 70- to 74-year-old age group to 97.6% of persons (n = 41) in the 85- to 89-year-old age group. A total of 56.4% of pers ons had cataract, aphakia, or pseudophakia in both eyes. Nuclear, cort ical, and posterior subcapsular opacities were detected in 38.5%, 37.6 %, and 27.7% of the participants, respectively. Exfoliation was presen t in one or both eyes in 22.1% of the participants. There was no diffe rence in the prevalence of cataract between the sexes when age was con sidered. Visual impairment to 20/50 or worse was at least partly due t o cataract in 23.8% of the right eyes and 22.4% of the left eyes. Sign ificant risk factors for cataract were age and the presence of exfolia tion in men and age, occupational exposure to sunlight, and current ci garette smoking in women. Conclusions: Almost two thirds of the popula tion 70 years of age or older had lens opacities, and in 23.1% of the eyes visual impairment to 20/50 or worse was at least partly due to ca taract. Including the patients who had undergone surgery, 30.3% of all the eyes of persons 70 years of age or older can be considered for ca taract surgery.