The Prevalence of Diabetic Retinopathy in Australian Adults with Self-Reported Diabetes: The National Eye Health Survey.

PURPOSE

To determine the prevalence of and factors associated with diabetic retinopathy (DR) among non-Indigenous and Indigenous Australian adults with self-reported diabetes.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Non-Indigenous Australians (50-98 years of age) and Indigenous Australians (40-92 years of age) with known diabetes.

METHODS

Diabetes was determined based on self-report of previous diagnosis of the disease. Nonmydriatic fundus photographs were obtained of each eye and graded according to the modified Airlie House classification system.

MAIN OUTCOME MEASURES

Any DR, vision-threatening DR (VTDR), treatment coverage rates (proportion of participants with proliferative DR [PDR], clinically significant macular edema [CSME], or both who had evidence of retinal scatter and focal laser treatment).

RESULTS

Four hundred thirty-one non-Indigenous Australians (13.9%) and 645 Indigenous Australians (37.1%) self-reported diabetes, of whom 93% (1004/1076) had retinal images that were gradable for DR. The sampling weight-adjusted prevalence of any DR and VTDR among non-Indigenous adults with self-reported diabetes was 28.5% (95% confidence interval [CI], 22.6-35.3) and 4.5% (95% CI, 2.6-7.9), respectively. Among adults 40 years of age and older, the sampling weight-adjusted prevalence of any DR and VTDR was 39.4% (95% CI, 33.1-46.1) and 9.5% (95% CI, 6.8-13.1), respectively. Longer diabetes duration was associated significantly with VTDR in the Indigenous Australian population (odds ratio [OR], 1.08 per 1-year increase; P = 0.005) and non-Indigenous Australian population (OR, 1.05 per 1-year increase; P = 0.03). The treatment coverage of PDR and CSME was 75% (56/75) in Indigenous Australians and 79% (15/19) in non-Indigenous Australians. Diabetic retinopathy was attributed as the main cause of vision loss (<6/12 in the better eye) in 9% and 19% of non-Indigenous and Indigenous Australian adults with known diabetes, respectively.

CONCLUSIONS

Three quarters of non-Indigenous and Indigenous Australian adults with PDR or CSME have received laser treatment. The prevalence of VTDR in Indigenous and non-Indigenous Australians in the present study was lower than that found in previous population-based reports, nevertheless, approximately 1 in 10 Indigenous adults with known diabetes experience VTDR. This highlights that intensified prevention strategies are required to delay or prevent avoidable vision loss resulting from DR in Indigenous Australian communities.