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A recent study published in Investigative Ophthalmology & Visual Science has highlighted the potential of optical coherence tomography angiography (OCTA) for detecting early vascular changes in diabetic retinopathy (DR). Researchers introduced six quantitative OCTA metrics to evaluate branching patterns and vascular fragmentation, measuring in both the foveal and parafoveal regions of the retina.
The team analyzed 99 eyes across three groups: healthy controls (HCs), patients with no DR, and patients with mild DR. The OCTA metrics included branch node number (BNN), branch node density (BND), end point density (EPD), fragmented vessel segment count (FVSC), and fragmented vascular length ratio (FVLR).
The results revealed that both BNN and BND were significantly reduced in patients with mild DR, especially in the deep vascular plexus (DVP), reflecting a loss of vascular complexity and early microvascular damage. Interestingly, BNN and BND in the fovea of the DVP could also distinguish preclinical changes in patients with diabetes but no DR.
In contrast, EPD was significantly elevated in the mild DR group, particularly in the DVP, suggesting compacted or shortened vessels due to disease progression. Additionally, both FVSC and FVLR were significantly increased in patients with mild DR, reflecting heightened vessel fragmentation and microvascular disruption. These changes were more prominent in the DVP, where smaller capillaries are more susceptible to damage from hyperglycemia.
The findings underscore the importance of evaluating the DVP layer for early signs of DR, say the authors, as DR exhibits more pronounced microvascular changes than the superficial vascular plexus (SVP). The novel OCTA metrics – particularly BND, EPD, FVSC, and FVLR – demonstrate significant promise for early DR detection, even before clinical manifestations arise. The study advocates incorporating these advanced OCTA parameters into routine diabetic retinopathy screening.
