Changing prevalence of retinopathy in T2D: one decade-long, observational study in 8,234 subjects

It is reported that the prevalence of diabetic microvascular complications is tending to decrease in recent years. However, information on how and to which extent this could be the case for diabetic retinopathy (DR) in T2D is still limited. Here we report data collected in our center from January 2010 to December 2019 in 8,234 consecutive T2D subjects who performed DR evaluation. The main clinical characteristics of the cohort were: M/F, 4,868/3,366; age, 61.5±10 years; known diabetes duration, 14±10 years; BMI, 29.3±7.9 kg/m2, fasting blood glucose, 148±34 mg/dl; HbA1c, 7.3±1.0%; total cholesterol, 175±30 mg/dl; LDL cholesterol, 98±26 mg/dl; systolic BP, 141±18 mmHg; diastolic BP, 78±9 mmHg; microalbuminuria, 63±240 mg/l; creatinine, 1.0±0.8 mg/dl. Fundus examination was performed with a non-mydriatic retinal camera (TRC-NW 100-Topcon) by taking 3 photographs for each eye (nasal, macular, and temporal field). The overall prevalence of DR was 25%. Multivariate analysis showed a direct correlation of DR with age, duration of diabetes, fasting blood glucose, HbA1c, microalbuminuria, systolic and diastolic blood pressure (all p<0.001), but not with lipid levels. We then subdivided the patients into two groups: group A included 4,199 patients who performed the fundus examination from January 2010 to December 2014, and group B consisted of 4,035 subjects who performed the examination from January 2015 to December 2019. The prevalence of RD was moderately, but significantly lower in group B compared to group A (23% vs 27%, p<0.05). The two groups did not differ for most of the main clinical features. However, we found a slightly, but significantly better metabolic control in group B compared to group A (HbA1c, 7.2±0.9 vs 7.4±1.1%; fasting plasma glucose, 146±33 vs 150±35 mg/dl; both p<0.05). The prevalence of patients taking GLP1-R agonists and/or SGLT2i drugs was higher in group B than group A (20% vs 5.4%, p<0.05). These results show a moderate, significant decrease of the prevalence of DR in T2D subjects over the years, which associates to improved glycemic control. The role of the novel antidiabetic drugs in this regard deserves further investigation.