OCT angiography offers promise for monitoring preclinical diabetic retinopathy

In this prospective analysis, researchers assessed perfused capillary density (PCD) in diabetic and healthy patients using OCT imaging.

Study design

This study included 40 healthy control patients, 36 diabetic patients without clinical evidence of diabetic retinopathy, 38 patients with nonproliferative diabetic retinopathy and 38 patients with proliferative diabetic retinopathy. Patients were imaged with spectral-domain OCT and OCT angiography. After manual delineation of the foveal avascular zone (FAZ), the FAZ area, perimeter and acircularity index as well as the annular PCD (%) were calculated.

Outcomes

The group with diabetes but no retinopathy had higher PCD compared with the control group in all 7 regions measured. However, the nonproliferative retinopathy and proliferative retinopathy groups showed progressively decreasing PCD.

Limitations

Although this study included a total of approximately 150 patients, it may not be representative of a wider group of patients.

Clinical significance

This work further establishes the potential role of OCT angiography to detect preclinical changes in the eyes of patients with diabetes. Interestingly, the increased PCD in patients with diabetes but no retinopathy may represent an autoregulatory response to increased metabolic demand. Meanwhile, the reduced capillary density with more advanced retinopathy may be due to damage to the capillaries and ongoing ischemia. This work highlights OCT angiography as a promising clinical tool to detect and monitor diabetes-induced changes in patients over time.