Abstract:Abstract: OBJECTIVE: This study aims to utilize Ultra-Wide-Field Swept-Source Optical Coherence Tomography Angiography (UWF-SS-OCTA) technology to quantitatively analyze the changes in blood flow density and thickness in the central and peripheral regions of the retina and choroid in patients with Non-Proliferative Diabetic Retinopathy (NPDR) with or without Diabetic Kidney Disease (DKD). Through this analysis, we evaluate the clinical utility and value of UWF-SS-OCTA in monitoring microvascular lesions in NPDR patients with DKD.METHODS: A cross-sectional study was conducted, including 50 diabetic patients who visited Shandong Second Medical University Affiliated Hospital from June 2023 to June 2024. Patients were divided into three groups based on their clinical conditions: NPDR with DKD group (DKD group, n=20), NPDR without DKD group (NDKD group, n=20), and diabetes without retinopathy group (NDR group, n=10, as a control). All enrolled patients underwent UWF-SS-OCTA examinations to obtain data on blood flow density and thickness in the central and peripheral regions of the retina and choroid. This included measurements of the superficial capillary plexuses (SCP), deep capillary plexus (DCP), choroidal capillary plexus (CCP), and mid-large choroidal vessel (MLCV) for vessel density (VD), as well as superficial retina thickness (SRT), deep retina thickness (DRT), and choroid thickness (CT). These parameters were then quantitatively analyzed to explore differences between groups and the impact of DKD on microvascular lesions in NPDR patients.RESULTS: (1) Compared to the NDKD group, the DKD group exhibited a significantly lower estimated glomerular filtration rate and a higher urine albumin-to-creatinine ratio (P<0.05). (2) Blood flow density in the peripheral region of the retina's SCP, as well as in the central and peripheral regions of the DCP, progressively decreased across the NDR, NDKD, and DKD groups (P<0.05). Statistically significant differences in the blood flow density of the SCP central region were observed between the NDR and DKD groups, and between the NDKD and DKD groups (P<0.05), but no statistical difference was found between the NDR and NDKD groups (P>0.05). (3) Blood flow density in the central and peripheral regions of the MLCV decreased progressively across the NDR, NDKD, and DKD groups (P<0.05), while significant differences in CCP blood flow density were noted between the NDR and DKD groups, and between the NDKD and DKD groups (P<0.05), with no differences between the NDR and NDKD groups (P>0.05). (4) Choroidal thickness in both central and peripheral regions decreased significantly in all three groups (P<0.05). The central and peripheral SRT and DRT showed statistically significant differences between the NDR and DKD groups (P<0.05), while no significant differences were observed between the NDR and NDKD groups, or between the NDKD and DKD groups (P>0.05).CONCLUSION: (1) The blood flow density of the CCP in NPDR patients with DKD is significantly decreased, suggesting that the reduction in CCP blood flow density may be associated with an increased risk of developing DKD. (2) The significant decrease in MLCV blood flow density in NPDR patients with DKD indicates that MLCV blood flow density could be a viable indicator for monitoring damage to the choroidal microvascular system in patients with diabetic kidney disease.(3) The marked reduction in choroidal thickness may indicate impaired renal function in NPDR patients.(4) This study provides scientific evidence for the application of UWF-SS-OCTA in the combined management of diabetic retinopathy and diabetic kidney disease, further promoting the development of non-invasive and precise monitoring and treatment technologies for diabetic ocular microvascular lesions.
