Objective: Identifying individuals most at risk for diabetic retinopathy progression and intervening early can limit vision loss and reduce the costs associated with managing more advanced disease. The purpose of this study was to identify factors associated with progression from nonproliferative diabetic retinopathy (NPDR) to proliferative diabetic retinopathy (PDR).
Research design and methods: This was a retrospective cohort analysis using a claims database of all eye care recipients age ≥ 30 years enrolled in a large managed-care network from 2001 to 2009. Individuals with newly diagnosed NPDR were followed longitudinally. Multivariable Cox regression analyses identified factors associated with progression to PDR. Three- and five-year probabilities of retinopathy progression were determined.
Results: Among the 4,617 enrollees with incident NPDR, 307 (6.6%) developed PDR. After adjustment for confounders, every 1-point increase in HbA1c was associated with a 14% (adjusted hazard ratio 1.14 [95% CI 1.07-1.21]) increased hazard of developing PDR. Those with nonhealing ulcers had a 54% (1.54 [1.15-2.07]) increased hazard of progressing to PDR, and enrollees with nephropathy had a marginally significant increased hazard of progressing to PDR (1.29 [0.99-1.67]) relative to those without these conditions. The 5-year probability of progression for low-risk individuals with NPDR was 5% (range 2-8) and for high-risk patients was 38% (14-55).
Conclusions: Along with glycemic control, nonophthalmologic manifestations of diabetes mellitus (e.g., nephropathy and nonhealing ulcers) are associated with an increased risk of diabetic retinopathy progression. Our retinopathy progression risk score can help clinicians stratify patients who are most at risk for disease progression.