There has been an increase in the range of non-insulin anti-hyperglycaemic agents used to treat type 2 diabetes. With the globally rising rates of type 2 diabetes and complications such as diabetic retinopathy, it is important for ophthalmologists to be aware of these new agents and their impacts on diabetic retinopathy and diabetic macular oedema. We conducted a review of the literature to determine if there were any beneficial or harmful effects of the currently used anti-hyperglycaemic agents on diabetic retinopathy or diabetic macular oedema. Our review of the current literature found that apart from thiazolidinediones, anti-hyperglycaemic agents have been reported to have beneficial or neutral effects on diabetic eye complications. Thiazolidinediones (pioglitazone is the only one currently available) have been linked to incident or worsening diabetic macular oedema, although the rate is believed to be low. Glucagon-like peptide 1 (GLP1) agonists (incretins) in general are beneficial except semaglutide which is associated with increased rates of diabetic retinopathy complications. These results have implications for selection of anti-hyperglycaemic agents for patients with diabetic retinopathy or macular oedema. Further studies need to be conducted to identify if reported beneficial effects are independent of the impact of glycaemic control. Early worsening of retinopathy with tight glycaemic control should also be noted in interpretation of future studies.

The present study identified that consistency in taking insulin and confidence in self-management was associated with better glycaemic control. An association was also found between recent dietary review and better carbohydrate knowledge, although this did not translate into better glycaemic control. Future investigation into the application of carbohydrate knowledge is required.

ObjectiveThere are limited data on the influence of ethnicity on diabetic retinopathy (DR). We sought to determine the distribution of DR by ethnic group in Australia.DesignClinic-based cross-sectional study.SettingParticipants with diabetes in a defined geographical region of Sydney, Australia, who attended a tertiary retina referral clinic.ParticipantsThe study recruited 968 participants.InterventionParticipants underwent a medical interview and retinal photography and scanning.Primary outcome measuresDR was defined from two-field retinal photographs. Diabetic macular oedema (DMO) was defined from spectral domain optical coherence tomography (OCT-DMO). The main outcomes were any DR, proliferative DR (PDR), clinically significant macular oedema (CSME), OCT-DMO and sight-threatening DR (STDR).ResultsThere was high proportion of any DR (52.3%), PDR (6.3%), CSME (19.7%), OCT-DMO (28.9%) and STDR (31.5%) in people attending a tertiary retinal clinic. Participants of Oceanian ethnicity had the highest proportion of any DR and STDR (70.4% and 48.1%, respectively), while the lowest proportion was in participants of East Asian ethnicity (38.3% and 15.8%, respectively). Proportion of any DR and STDR in Europeans was 54.5% and 30.3%, respectively. Independent predictive factors for diabetic eye disease were ethnicity, longer duration of diabetes, higher glycated haemoglobin and higher blood pressure. Even after adjusting for risk factors, Oceanian ethnicity remained associated with twofold higher odds of any DR (adjusted OR 2.10, 95% CI 1.10 to 4.00) and all other forms of DR including STDR (adjusted OR 2.22, 95% CI 1.19 to 4.15).ConclusionIn people attending a tertiary retinal clinic, the proportion of people with DR varies among ethnic groups. The high proportion in persons of Oceanian ethnicity suggests a need for targeted screening of this at-risk group. In addition to traditional risks factors, ethnicity may be an additional independent predictor of DR.

PurposeThe population prevalence of diabetic macular oedema (DME) is unclear. Previous estimates have depended on photographic grading of clinically significant macular oedema, which is subjective and has resulted in widely varying estimates. With the advent of optical coherence tomography (OCT), the presence and severity of DME can now be assessed objectively and accurately.MethodsThe Liverpool Eye and Diabetes Study (LEADS) is a cross-sectional population-based study of patients with type 1 and type 2 diabetes in a multi-ethnic region of Sydney, Australia, to determine the population prevalence of OCT-defined DME, how this varies by ethnicity and association with systemic factors. This report describes the rationale, methodology and study aims.ResultsTo date 646 patients out of an expected sample size of 2000 have been recruited. Baseline data are presented for patients with type 1 (n=75, 11.8%) and type 2 (n=562, 88.2%) diabetes recruited to date. Patients with type 1 diabetes were younger (39.5vs60.7 years), with longer duration of diabetes (18.1vs11.7 years), slightly worse glycaemic control (HbA1c 9.0vs8.3), and less likely to have hypertension (30.7vs71.4%), hypercholesterolaemia (33.3vs74.6%) and obesity (31.1vs51.5%, respectively, all p<0.05).ConclusionsThe LEADS will provide objective estimates of the population prevalence of DME, how this varies with ethnicity and associations with systemic disease.