The prevalence and causes of vision loss in Indigenous Australians: the National Indigenous Eye Health Survey

Abstract

Aim: To determine the prevalence and causes of vision loss in Indigenous Australians.

Design, setting and participants: A national, stratified, random cluster sample was drawn from 30 communities across Australia that each included about 300 Indigenous people of all ages. A sample of non-Indigenous adults aged > or = 40 years was also tested at several remote sites for comparison. Participants were examined using a standardised protocol that included a questionnaire (self-administered or completed with the help of field staff), visual acuity (VA) testing on presentation and after correction, visual field testing, trachoma grading, and fundus and lens photography. The data were collected in 2008.

Main outcome measures: VA; prevalence of low vision and blindness; causes of vision loss; rates of vision loss in Indigenous compared with non-Indigenous adults.

Results: 1694 Indigenous children and 1189 Indigenous adults were examined, representing recruitment rates of 84% for children aged 5-15 years and 72% for adults aged > or = 40 years. Rates of low vision (VA < 6/12 to > or = 6/60) were 1.5% (95% CI, 0.9%-2.1%) in children and 9.4% (95% CI, 7.8%-11.1%) in adults. Rates of blindness (VA < 6/60) were 0.2% (95% CI, 0.04%-0.5%) in children and 1.9% (95% CI, 1.1%-2.6%) in adults. The principal cause of low vision in both adults and children was refractive error. The principal causes of blindness in adults were cataract, refractive error and optic atrophy. Relative risks (RRs) of vision loss and blindness in Indigenous adults compared with adults in the mainstream Australian population were 2.8 and 6.2, respectively. By contrast, RRs of vision loss and blindness in Indigenous children compared with mainstream children were 0.2 and 0.6, respectively.

Conclusion: Many causes of vision loss in our sample were readily avoidable. Better allocation of services and resources is required to give all Australians equal access to eye health services.