Glycemic variability and diabetes retinopathy: a missing link.

Daily glucose variability, such as fasting plasma glucose fluctuation or postprandial hyperglycemia, has been proposed as contributors to diabetes-related macrovascular complications. However, its impacts on microvascular complications, such as diabetes retinopathy remain controversial. We reviewed the current evidence of the relationship between glycemic variability and diabetes retinopathy in patients with type 1 or type 2 diabetes. In general, the short-term glycemic fluctuation, either expressed as standard deviation of fasting glucose or mean glucose levels, may contribute to the development or progression of diabetic retinopathy in patients with type 2 diabetes, whereas long-term glycemic fluctuation, reflected by variation of levels of HbA1c, appeared to show a stronger association with diabetes retinopathy both in patients with type 1 and type 2 diabetes. These findings emphasize the need to reduce glycemic variability by various measures in order to reduce development and progression of diabetes retinopathy both in type 1 and type 2 diabetes patients.