Rates of nonproliferative diabetic retinopathy (NPDR) regression among patients with very mild or mild NPDR in an Indian Health Service teleophthalmology program, 2015 – 2020

Diabetic retinopathy (DR) regression is not regularly reported; yet understanding of its prevalence in early-stage DR may impact strategies for eye care management. This study's primary aim was to examine DR regression in patients initially diagnosed with very mild or mild nonproliferative DR (NPDR). A secondary aim was to assess the association between retinopathy regression and diabetes therapy, diabetes duration, and Hemoglobin A1c (HbA1c). This was a retrospective, longitudinal cohort study using medical record data from the United States's Indian Health Service's teleophthalmology program for DR evaluation. Baseline exams occurred in 2015-2017 and follow-up (FU) exams occurred within 3 years of baseline. There were 2,348 patients included in this cohort with very mild NPDR at baseline and 705 patients with mild NPDR. For the whole sample, mean age was 56 ± 12.8 years, 55% were female, diabetes duration was 13.0 ± 9.1 years, and HbA1c was 8.8 ± 2.1%. Proportions for DR regression were 0.47 (CI = .45 - .50) (from very mild NPDR) and 0.36 (CI = 0.33-0.40) (from mild NPDR). Proportions for any DR progression were 0.27 (CI = 0.25-0.29) (from very mild NPDR) and 0.34 (CI = 0.30-0.38) (from mild NPDR). Multivariable analyses showed that lower HbA1c levels were associated with greater odds of diabetic retinopathy regression in patients with either very mild or mild baseline NPDR, whereas insulin use was associated with lower odds of regression. Shorter diabetes duration was associated with greater odds of regression only among patients with very mild NPDR at baseline. DR regression was more frequent than DR progression particularly for patients initially with very mild NPDR. DR reversal was more likely in early-stage DR. Behavioral modifications such as increased physical activity and weight loss that lower HbA1c and subsequent risks for DR progression are important to emphasize in diabetic eye care.