Author: Jose Estevez Bordon
Estevez Bordon, Jose, 2024 Characterising the Epidemiology, Risk Factors, Screening and Treatment Outcomes for Diabetic Retinopathy among Aboriginal and Torres Strait Islander People, Flinders University, College of Medicine and Public Health
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Type 2 diabetes mellitus (T2DM) poses significant challenges to individuals and society, with an enormous burden borne by disadvantaged and marginalised populations, such as Indigenous peoples. The increasing prevalence of T2DM among Indigenous people has meant that rates of blindness and diabetes-related complications remain a priority health concern. T2DM not only causes diabetic retinopathy (DR), the microvascular complication that leads to irreversible blindness, but also contributes to increasing rates of vision loss from other causes, such as refractive error and cataract. Even though Australia's health care system is rich in resources relative to different parts of the world, it continues to struggle to adequately respond to the health needs of its Aboriginal and Torres Strait Islander population living with T2DM, including preventing blindness from associated complications. Trends among Indigenous Australians highlight that DR has almost doubled over two decades, and diabetes-related vision impairment is consistently higher among Aboriginal and Torres Strait Islander communities when compared to other Australians. While Australia has collated reliable estimates of the eye health burden owing to T2DM, there is limited knowledge on the epidemiology of vision loss, the underlying risk factors, how to screen for eye complications within healthcare settings adequately and whether treatment outcomes are meeting population-based eye care needs.
Using an epidemiological framework analysis on a landmark population-based cohort studies into T2DM, its complications and determinants, this Higher Degree Research program comprehensively characterised the underlying social, clinical, and biological risk factors and – importantly – integrated this data to give valuable insights into the most critical determinants contributing to blindness and retinal complications among a cohort of Aboriginal and Torres Strait Islander people. Additionally, healthcare utilisation data, treatment outcomes and novel approaches to screening for DR that could be implemented to overcome barriers to accessing high-quality eye care were explored. The Predicting Renal Ophthalmic and Heart Events in the Aboriginal Community (PROPHECY) study, alongside the Retinopathy in People Currently On Dialysis (RiPCORD) study, were integral components of this research program. PROPHECY was designed to elucidate the risks and complications associated with diabetes, while RiPCORD sought to epidemiologically examine the prevalence of eye diseases among individuals undergoing haemodialysis treatment.
The studies found high rates of visual disability and DR-related morbidity, particularly in individuals with modifiable socioeconomic factors such as education and employment. Biological risk factors such as inflammation and the burden of comorbidities such as chronic kidney disease was associated with DR. There were inequalities in access to screening, with younger individuals, those living in remote areas, and those experiencing financial insecurity having inadequate rates of DR screening. Single-field retinal photography was a valid approach to screening, but agreement and sensitivity for diabetic macular oedema were suboptimal compared to clinician-led examinations with optical coherence tomography scans. Furthermore, there was a relative quality gap for DR treatments, particularly for women, indicating a need for improved access to and provision of DR treatments. These findings highlight the need to improve screening and preventative treatments and provide high-quality interventions for vision loss and DR, particularly for those at risk of progression based on their identified social, clinical, and biological risk.
Keywords: diabetes, health equity, Aboriginal and Torres Strait Islander health, diabetic retinopathy, vision loss, blindness, epidemiology, risk factors
Subject: Medicine thesis
Thesis type: Doctor of Philosophy
Completed: 2024
School: College of Medicine and Public Health
Supervisor: Professor Jamie Craig