Eyes with moderate to severe nonproliferative diabetic retinopathy more often develop eye worsening compared to those with a milder form of the condition.
Eyes with moderate to severe nonproliferative diabetic retinopathy are at the greatest risk of progression to vision-threatening forms of the condition.
The findings of the research were presented at the American Society of Retina Specialists (ASRS 2020) Virtual Sessions.
Geeta Lalwani, MD, and colleagues assessed the risk of diabetic retinopathy progression among real-world patients with diabetes in a primary care setting. To characterize the rates of diabetic retinopathy progression, the team conducted a post-hoc analysis of a database of patients with diabetes who participated in a retina screening program.
Eyes were included in the study if they had more than 2 valid Early Treatment Diabetic Retinopathy (ETDRS) Diabetic Retinopathy Severity Scale (DRSS) assessments at 2 separate time points. Poor images, no images, or images available at only one time point were excluded.
Nearly 42,000 eyes were included from 22,116 patients with diabetes. Professional graders assessed diabetic retinopathy severity and clinically significant macular edema from seven-field color fundus photographs. A two-step diabetic retinopathy worsening was assessed in the overall population and by DRSS at baseline.
Patients included were predominantly male (83%) and a majority were either white (48%) or Native American (41%). Those included mostly had type 2 diabetes (94.2%).
Almost 10% of eyes experienced at least two-step diabetic retinopathy worsening by year 5. When the team looked at the same data stratified by baseline diabetic retinopathy severity, there was a distinct increase in rate of progression in patients with moderate to severe nonproliferative diabetic retinopathy at baseline.
For those eyes with moderate to severe nonproliferative diabetic retinopathy at baseline, greater than 35% of those eyes went on to develop a two-step diabetic retinopathy worsening by year 5. For moderately severe nonproliferative diabetic retinopathy at baseline, 40% of those eyes developed a two-step diabetic retinopathy worsening by year 5.
Lalwani and the team also assessed the time to the first development of clinically significant macular edema or proliferative diabetic retinopathy in eyes without such conditions at baseline. Slightly more than 1.5% of patients developed either of the conditions. Less than 1.5% developed clinically significant macular edema while roughly .5% developed just proliferative diabetic retinopathy and .1% developed both conditions.
When stratified looking at patients who had moderate to severe nonproliferative diabetic retinopathy at baseline, the numbers significantly increased. More than 25% of patients developed clinically significant macular edema or proliferative diabetic retinopathy at year 4, 20% developed clinically significant macular edema alone, 10% developed proliferative diabetic retinopathy alone, and 2.5% developed both conditions.
In eyes with moderately severe nonproliferative diabetic retinopathy, the numbers were even higher.
Overall, 8-13% of patients developed a two-step diabetic retinopathy worsening at year 2, while more than 35% of eyes developed worsening at year 5 compared to those with mild nonproliferative diabetic retinopathy who had little to no worsening.
The study, “Insights Into the Progression of Diabetic Retinopathy Severity Among Primary Care Patients With Diabetes in the United States,” was presented at ASRS 2020.