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.