Ten-year incidence of age-related cataract and cataract surgery in an older Australian population - The Blue Mountains Eye Study

Purpose: To estimate the 10-year incidence of cataract and cataract surgery in an older Australian population. Design: Prospective population-based study. Participants: Persons at least 49 years old living in 2 postcode areas west of Sydney, Australia. Methods: Eye examinations were performed at baseline and at 5- and 10-year follow-up visits. Lens photographs were taken and graded by masked graders using the Wisconsin Cataract Grading System. Main Outcome Measures: Incidences of nuclear cataract, cortical cataract, posterior subcapsular cataract (PSC), and cataract surgery. Results: Ten-year person-specific incidences were 36.0% for nuclear cataract, 28.0% for cortical cataract, 9.1% for PSC, and 17.8% for cataract surgery. Corresponding rates were 31.7%, 24.4%, 8.2%, and 14.4%, respectively, in men and 39.3%, 30.8%, 9.8%, and 20.1%, respectively, in women. The incidence for each type of cataract and cataract surgery was positively associated with age (P<0.0001). Women had a significantly higher incidence than men for nuclear cataract (P = 0.04), cortical cataract (P = 0.007), any cataract (P = 0.0006), and cataract surgery (P = 0.03) after adjusting for age. There was no significant gender difference for PSC. The mean age at cataract surgery was 75.8 years, and there was no significant gender difference (P = 0.9). Among persons who developed any cataract, 22% had more than one type and 1.3% had all 3 types present. Nuclear cataract and PSC were significantly associated with visual impairment (visual acuity worse than 20/40). Conclusion: Age- and gender-specific cataract incidences in this study were similar to those reported from the U.S. Beaver Dam Eye Study. In this study, 72% of the participants were affected by cataract or had had cataract surgery over the 10-year follow-up period.