While not yet a mainstream technology, optical coherence tomography angiography (OCT-A) continues to demonstrate an expansive array of skills. Researchers recently used it to identify changes in perfused capillary density (PCD), which are possible harbingers of early, preclinical diabetic retinopathy (DR).

The study, published in the American Journal of Ophthalmology, used OCT-A to image 36 patients with diabetes but no clinical DR, 38 diabetes patients with nonproliferative DR, 38 with proliferative DR and 40 controls. Investigators assessed the foveal avascular zones within the 3mm x 3mm full-thickness parafoveal OCT-A scans and discovered the diabetes patients without clinical DR had consistently higher PCD compared with controls. However, study participants with nonproliferative and proliferative DR demonstrated progressively decreasing PCD.

The increased PCD values in patients without DR “likely represent an autoregulatory response to increased metabolic demand,” the study says. The decrease in PCD found in patients with some form of retinopathy suggests an incremental loss of capillary segments.

“These findings, consistent with previous studies, demonstrate the potential of OCT-A as a clinical tool for earlier objective detection of preclinical diabetic retinopathy,” the authors conclude in the study.