Four-Year Screening Interval and Vision-Threatening Retinopathy in Type 2 Diabetes Patients With Good Glycemic Control

Objective: To assess whether vision-threatening retinopathy developed after 4 years in patients with type 2 diabetes with good glycemic control during follow-up. Patients and Methods: Using data from the Action to Control Cardiovascular Risk in Diabetes and Action to Control Cardiovascular Risk in Diabetes Follow-on studies (conducted from January 1, 2001, to October 14, 2014), we investigated the incidence of vision-threatening retinopathy after 4 years in patients with type 2 diabetes with good or poor glycemic control. Patients with proliferative diabetic retinopathy at baseline were excluded. Vision-threatening retinopathy was defined as severe nonproliferative diabetic retinopathy, proliferative diabetic retinopathy, laser photocoagulation, or vitrectomy. Good and poor glycemic control was defined as mean glycated hemoglobin level less than 7% and 7% or greater during follow-up, respectively. Results: This study included 2285 patients. Among patients with no retinopathy at baseline, the 4-year incidence of vision-threatening retinopathy was 0% (0 of 386) and 0.8% (6 of 721) in those with good and poor glycemic control, respectively (P=.54). Similarly, severe retinopathy was not observed at 8 years in patients who did not have retinopathy at 4 years. Among patients with mild to moderate nonproliferative diabetic retinopathy at baseline, the 4-year incidence of vision-threatening retinopathy was significantly higher in those with poor glycemic control than in those with good glycemic control (9.7% [77 of 790] vs 4.4% [13 of 297]; P=.004) . Additionally, the remission rate of diabetic retinopathy was low in patients with a long duration of diabetes. Four-year incidences of vision-threatening retinopathy were higher in patients with retinopathy at baseline who had poorer glycemic control and longer durations of diabetes. Conclusion: It may be safe to extend screening intervals for diabetic retinopathy to 4 years or longer in patients with type 2 diabetes with no retinopathy. (C) 2020 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc.

Automated summary

The study found that patients with type 2 diabetes who had good glycemic control during follow-up had a lower incidence of vision-threatening retinopathy; for patients with mild to moderate nonproliferative diabetic retinopathy, poor glycemic control significantly increased the incidence of vision-threatening retinopathy; patients with longer durations of diabetes had lower rates of remission of diabetic retinopathy.