Diabetic retinopathy diagnoses growing in U.S.

For the first time, a comprehensive statistical analysis has enabled researchers to estimate the number of Americans of all ages living with diabetic retinopathy.

The study by researchers at the Centers for Disease Control and Prevention, the University of Washington School of Medicine, and NORC (formerly called the National Opinion Research Center) at the University of Chicago indicates that 9.6 million people had diabetic retinopathy in 2021. That’s about 30 percent higher than the previous research had predicted. Of those, 1.8 million have vision-threatening disease.

About 1 out of 4 people living with diabetes, at least age 40 and older, have diabetic retinopathy. Diabetes affects more than 37 million Americans, a count that grows with obesity and poor nutrition. Diabetic retinopathy occurs when high blood sugar damages small blood vessels in the retina. This can lead to vision loss.

The study was published in June in JAMA Ophthalmology. The study's co-authors include Dr. Aaron Lee, MD, C. Dan and Irene Hunter Endowed Professor from UW Medicine Ophthalmology, Abraham Flaxman, associate professor in global health and health metrics sciences, and an adjunct associate professor of computer science and engineering, and Zeb Burke-Conte at the Institute for Health Metrics and Evaluation also contributed to the research.

Researchers used data from the CDC’s Vision and Eye Health Surveillance System, which collated information from the National Health and Nutrition Examination Survey, Medicare and private insurance claims, and studies of adult eye disease and diabetes in youth.

The authors’ major challenge was that, in 2008, the CDC stopped including direct measurements of diabetic retinopathy in its flagship National Health and Nutrition Examination Survey, Flaxman said. “It’s been a long time and diabetes is something that has been changing over 15 years.”

A map generated for the study shows diabetic retinopathy hotspots around the nation. The investigators hope the research can be used to allocate public health resources and interventions to high-risk communities.

A limitation of this work, the researchers said, is that unfortunately, this is not the kind of analysis that says why. Reasons might include better diagnostic abilities and greater access to healthcare, meaning patients are counted at a higher rate than in other states. Or it might mean that something inscrutable is going on with vision and eye care here that we can’t yet identify. Knowing where to look is the first step to finding meaningful context. The new analysis is a reminder of how important baseline analyses are for the greater good.