Quantitative analysis of retinal and choroid capillary ischaemia using optical coherence tomography angiography in type 2 diabetes.

To perform a quantitative analysis of retinal and choroid capillary ischaemia in diabetic patients by using optical coherence tomography angiography (OCTA). A total of 97 type 2 diabetic patients and 48 controls were included in this cross-sectional study. Diabetic patients without diabetic retinopathy (DR) were categorized as no DR (NDR) group; DR was classified into mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR and proliferative diabetic retinopathy (PDR). Quantitative parameters included foveal and parafoveal vascular density (VD) in superficial, deep and choroid capillary plexus (SCP, DCP and CCP), and foveal flow area in CCP. Stepwise comparisons between groups were performed in the adjacent stages. Diabetic patients had significantly lower flow area in CCP and VD in all three layers compared with controls. In NDR group, foveal flow area in CCP significantly decreased compared with controls. In mild NPDR, parafoveal VD significantly decreased in all three layers compared with NDR, especially in temporal and nasal areas. In moderate NPDR, VD reduction extended to the inferior area in SCP and DCP compared with mild NPDR. In severe NPDR, progressive losses of VD were presented in all layers compared with moderate NDPR. In PDR, the superior VD in SCP significantly increased compared with severe NPDR. In diabetic patients, the microvascular ischaemia originated in choroid layer and extended inward affecting the deep and superficial layer. OCTA can serve as a reliable method for early detection and to monitor progressions in diabetic retinopathy.

Li L ，Almansoob S ，Zhang P ，Zhou YD ，Tan Y ，Gao L ... -  《-》

Interaction Between the Distribution of Diabetic Retinopathy Lesions and the Association of Optical Coherence Tomography Angiography Scans With Diabetic Retinopathy Severity.

Ashraf M ，Sampani K ，Rageh A ，Silva PS ，Aiello LP ，Sun JK ... -  《-》

Macular Capillary Perfusion in Chinese Patients With Diabetic Retinopathy Obtained With Optical Coherence Tomography Angiography.

To compare the macular perfusion in the retina and choroidal layer between control subjects and Chinese patients with diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA) and to evaluate the association of OCTA characteristics with the stage of DR. A total of 200 eyes (normal controls = 40; mild non-proliferative diabetic retinopathy [NPDR] = 40; moderate NPDR = 40; severe NPDR = 40; and PDR [proliferative diabetic retinopathy] = 40) underwent OCTA imaging. OCTA parameters were vessel densities in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris, as well as foveal avascular zone (FAZ) area (mm2) in the SCP. The reduction of macular perfusion in the SCP, DCP, and choriocapillaris was correlated with increasing severity of DR. Vessel density in the SCP, DCP, and choriocapillaris was 55.31% ± 2.56%, 62.40% ± 2.46%, and 66.87% ± 1.30%, respectively, in control subjects; 50.58% ± 3.14%, 56.31% ± 4.24%, and 66.20% ± 1.69%, respectively, in mild NPDR; 46.46% ± 3.09%, 49.40% ± 5.68%, and 64.39% ± 1.94%, respectively, in moderate NPDR; 45.61% ± 3.81%, 49.33% ± 6.14%, and 63.75% ± 2.21%, respectively, in severe NPDR; and 43.78% ± 3.71%, 44.78% ± 6.36%, and 61.32% ± 6.29%, respectively, in PDR. Vessel density in DR groups decreased compared with normal controls (P < .001). FAZ area in the SCP was 0.34 ± 0.09 mm2 in control subjects compared with 0.48 ± 0.17 mm2 (mild NPDR), 0.52 ± 0.13 mm2 (moderate NPDR), 0.62 ± 0.24 mm2 (severe NPDR), and 0.75 ± 0.30 mm2 (PDR). FAZ in the SCP of patients with DR was greater than that in control subjects (P < .001). Vessel density in the DCP shows better ability to identify the severity of DR (area under the curve, sensitivity, and specificity of 0.967, 92.5%, and 93.1%, respectively) than vessel density in the SCP and choriocapillaris. OCTA might be clinically useful to evaluate different stages of DR in a noninvasive manner. Vessel density in DCP could be an objective and reliable indicator for monitoring progression of DR. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e88-e95.].

Yang D ，Cao D ，Huang Z ，Xie J ，Meng Q ，Dong X ，Hu Y ，Zeng Y ，Zhang L ... -  《-》

Retinal vasculature-function correlation in non-proliferative diabetic retinopathy.

Zeng Y ，Cao D ，Yang D ，Zhuang X ，Hu Y ，He M ，Yu H ，Wang J ，Yang C ，Zhang L ... -  《-》

Correlation between vessel density and thickness in the retina and choroid of severe non-proliferative diabetic retinopathy patients.

To explore the correlation between the vessel density (VD) of the retina and choroid vascular plexuses and the thicknesses of their respective retinal layers and choroid membranes in participants with severe non-proliferative diabetic retinopathy (NPDR). We retrospectively analyzed the data of 42 eyes of 42 participants with diabetes mellitus (DM) and severe NPDR. In addition, 41 eyes of 41 healthy controls were evaluated. Measurements were taken for both groups using optical coherence tomography angiography (OCTA), including the area and perimeter of the foveal vascular zone (FAZ) and the vascular density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choroid capillary (CC). These measurements were compared with the retinal thickness (RT) of the inner/intermediate retinal layers and choroidal thickness (CT). The study evaluated the correlation between RT or CT and VD in the respective vascular networks, namely superficial capillary plexus (SCP), deep capillary plexus (DCP), or CC. The inner RT and VD in all plexuses were significantly lower in the severe NPDR group than in the healthy controls. Furthermore, the FAZ area and perimeter were larger in the severe NPDR group. Inner RT was correlated with VD in the SCP group (r=0.67 and r=0.71 in the healthy control and severe NPDR groups, respectively; p<0.05). CT negatively correlated with VD in the CC (r=-0.697 and r=-0.759 in the healthy control and severe NPDR groups, respectively; p<0.05). Intermediate RT significantly correlated with VD in the DCP of the severe NPDR group (r=-0.55, p<0.05), but not in the healthy control group. Retinal or choroidal thickness strongly correlated with VD. Therefore, patients with severe NPDR must consider the distinct anatomical and functional entities of the various retinal layers and the choroid.

He K ，Wei-Zhang S ，Li Z ，Kaysar P ，Yang T ，Sun Z ，Zhou W ，Yan H ... -  《Frontiers in Endocrinology》