Risk factors for diabetic retinopathy blindness and its treatment

Author: Ebony Liu

Liu, Ebony, 2021 Risk factors for diabetic retinopathy blindness and its treatment, Flinders University, College of Medicine and Public Health

Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.

Abstract

Diabetes retinopathy (DR), the current fifth most common cause of blindness worldwide, is on an exponential rise. Recent reports predict that the prevalence of DR will increase from an estimated 146 million to 224 million worldwide by the year 2040. Despite significant progress in reducing the rates of blindness, several challenges remain in its management. This thesis focuses on building knowledge in two important areas of reducing the burden of DR: 1) the disproportionate burden of DR in indigenous Australian populations and 2) the complex genetic nature of DR and its implications for risk stratification and treatment.

Two epidemiology studies were undertaken to explore the burden of DR among indigenous Australian communities. Strong associations were confirmed between DR and higher mortality, renal disease, poor DR screening rates and adherence to treatment. A randomized clinical trial was conducted to compare intravitreal bevacizumab and intravitreal dexamethasone implant in the treatment of diabetic macular oedema. Results support the preferential use of intravitreal dexamethasone implant in resource poor settings. Large genetic studies were conducted to explore three groups of genes and their association with DR. Mitochondria haplogroup, microRNA and its binding sites, and VEGF receptor genes were chosen because of the lack of studies from the literature and their proximity to the molecular pathogenesis of DR. Mitochondrial haplogroup was not shown to be associated with DR in a Caucasian population, however significant results were found for single nucleotide polymorphisms (SNP) in microRNA, its binding sites, and VEGF receptor.

Outcomes from this thesis have direct implications in improving our current approach to the treatment of DR. Epidemiology trends from indigenous communities emphasise the importance of working within existing health frameworks and community collaboration in disease prevention. New genetic findings guide the direction of future work in developing effective and targeted treatments. The results from this thesis contribute to an ongoing research initiative to improve our understanding of DR and its treatment.

Keywords: diabetic retinopathy, indigenous health, genetic studies, epidemiology

Subject: Ophthalmology thesis

Thesis type: Doctor of Philosophy
Completed: 2021
School: College of Medicine and Public Health
Supervisor: Jamie Craig