Differences in retinopathy prevalence and progression between Anglo‐Celt and Aboriginal Australians: the Fremantle Diabetes Study Phase II

Abstract

Background: Indigenous populations have higher rates of diabetes and diabetic complications, yet there is a paucity of contemporary data on diabetic retinopathy (DR) prevalence and incidence in urban dwelling Aboriginal Australians. Aims:The aim of the study was to compare the prevalence of DR and incidence of new or worsening DR between Aboriginal Australians and Anglo-Celts with Type 2 diabetes.Methods: Participants from the community-based Fremantle Diabetes Study Phase II (817 Anglo-Celts, 94 Aboriginal people) recruited between 2008 and 2011 underwent fundus photography at baseline and biennial reviews. The prevalence of any DR and moderate non-proliferative DR (NPDR), and the incidence of new or worsening DR were ascertained using baseline and 4-year follow-up data.Results: Compared with Anglo-Celts, the Aboriginal participants had a higher prevalence of any DR (33.0% vs 52.1%) and moderate NPDR or worse (5.1% vs 24.4%), and new or worsening DR during follow up (6.7% vs 23.5%). The unadjusted odds ratios (95% confidence interval) of any DR and moderate NPDR at baseline were 2.21 (1.43, 3.39) and 5.98 (3.40, 10.50), respectively, and of new or worsening DR 4.32 (1.33, 13.98). In adjusted models, Aboriginal ethnicity was only associated with the prevalence of moderate NPDR or worse (5.58 (2.44, 12.76)).Conclusions: Aboriginal participants had a higher prevalence of DR and new or worsening DR, reflecting conventional risk factors including suboptimal glycaemic control. Their significantly higher odds of moderate NPDR or worse in adjusted models suggest ethnic-specific determinants of DR severity. These findings highlight the need for equitable, culturally appropriate diabetes/ophthalmic care.

Prevalence of Diabetic Retinopathy in Indigenous and Non-Indigenous Australians

“…The National Eye Health Survey and the Fremantle Diabetes Study II both found higher DR prevalence amongst Indigenous participants. 7,8 Considering methodological differences between studies, consistency of within-study comparisons amongst high-quality studies adds strength to our conclusions.…”

“…Of these, 15 studies enrolling 8219 diabetic participants were included in our systematic review and metaanalysis. 7,8,[24][25][26][27][28][29][30][31][32][33][34][35][36]…”

“…More recently, several additional Australian DR prevalence studies have been published, including two population-based studies which reported the opposite finding of increased DR prevalence in Indigenous Australians. 7,8 Understanding ethnic variation in disease prevalence is important for identifying key health priorities to policymakers in order to reduce health inequity. Epidemiological studies may also lead to the identification of ethnic-specific modifiable risk factors that can be targeted to reduce morbidity.…”

Proportion of people with diabetic retinopathy and macular oedema varies by ethnicity in a tertiary retinal clinic in Australia: findings from the Liverpool Eye and Diabetes Study (LEADS)

“…3 Future studies may need to study these potential ethnic differences in greater detail. It is likely that the higher rates of DR in Oceanians are related to many of the same ethnic-specific factors that underlie the higher rates in Indigenous Australians, 22 such as low income, less access to quality food and diabetes medical care, and other culture-specific health behaviours. These areas may need to be studied further in order to reduce the gap in DR rates between different ethnic groups.…”

Retinopathy prevalence, incidence and trajectories in type 2 diabetes: The Fremantle diabetes study phase II

“…Diabetic retinopathy was assessed according to the modified Airlie House Classification system for the Early Treatment Diabetic Retinopathy Study. 16,17 As the original grader was unavailable, follow-up fundus photographs were first assessed independently by an experienced ophthalmologist under the same system used for the baseline images. A second ophthalmologist (AT) graded all photographs assessed as showing DR by the first, and he also graded a randomly-selected sample of the remaining images.…”