Investigation of the impact of choroidal capillary flow area on macular ischemia in diabetic patients.

This cross-sectional study investigated the correlation between choriocapillaris flow area (CCFA) and retinal vascular changes in diabetic macular ischemia (DMI) using optical coherence tomography angiography (OCTA). Age-matched participants were divided into three groups: control (46 eyes), diabetic without macular ischemia (Non-DMI, 59 eyes), and diabetic with macular ischemia (DMI, 54 eyes). Correlation analyses between CCFA and retinal capillary density were performed using OCTA. Results showed that CCFA was significantly reduced in the DMI group compared to the control and Non-DMI groups (H(2) = 40.526, P < 0.01). CCFA was positively correlated with the density of the superficial and deep capillary plexuses (SCP: H(2) = 40.526, P < 0.01; DCP: H(2) = 30.942, P < 0.001), negatively correlated with the foveal avascular zone perimeter (FAZ-P: H(2) = 7.841, P = 0.02), and positively correlated with the acircularity index (FAZ-CI: H(2) = 20.3, P  < 0.001). Our study results show that the choriocapillaris flow area (CCFA) is significantly reduced in patients with diabetic macular ischemia (DMI) and is strongly correlated with retinal capillaries. This may reflect concurrent microvascular impairment in both the retina and choroid. Further longitudinal studies are needed to validate the feasibility of CCFA as a potential imaging biomarker for the early detection and monitoring of DMI.