Ocular and Systemic Risk Markers for Development of Macular Edema and Proliferative Retinopathy in Type 2 Diabetes: A 5-Year Longitudinal Study

Diabetic retinopathy (DR) is a common complication of diabetes and may lead to blindness through vision-threatening complications, such as diabetic macular edema and proliferative DR (PDR). Several studies have established that certain systemic factors have associations with incidence and progression of DR, namely, glycemic control, arterial hypertension, high cholesterol and hyperlipidemia obesity, inflammatory markers, sleep-disordered breathing, and exercise (1,2). In addition to systemic factors, there are ocular factors that should be considered, since they may identify the eyes at risk (2). We here report a 5-year prospective longitudinal observational cohort study that investigates the risk of both systemic and ocular factors that may play a role in the development of diabetic macular edema and PDR, the vision-threatening complications of DR. This observational cohort study included eyes/patients with mild nonproliferative PDR, Early Treatment Diabetic Retinopathy Study (ETDRS) classification grades 20 and 35 (3), who were followed for a period of 5 years or until the time of development of center-involved macular edema (CIME), clinically significant macular edema (CSME), or PDR. A total of 212 patients were included: men and women with diagnosed adult-onset type 2 diabetes, aged 42–82 years, with a maximum baseline HbA1c value of 10% (86 mmol/mol). Exclusion criteria included any laser treatment or intravitreal injections or any other comorbidity that could affect the retina. …