Objective:To investigate the characteristics of macular perfusion and structures in patients with early stages of diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA).Methods:A cross-sectional study was performed.Forty eyes of 27 diabetic patients without diabetic retinopathy (NDR), forty eyes of 24 patients with mild non-proliferative diabetic retinopathy (NPDR) and forty eyes of 28 patients with moderate NPDR were recruited in Guangdong Provincial People's Hospital from June 2017 to August 2018.RTVue-XR OCTA was used to scan a 6 mm×6 mm area centered in the fovea and the superficial vascular complex (SVC) and deep vascular complex (DVC) vessel density, fovea avascular zone (FAZ) area, FAZ perimeter, acircularity index (AI), and vessel density of a 300 μm wide ring area around FAZ (FD300) were quantified.The associations among stages of DR and macular vessel density, structures were analyzed.This study was approved by the Ethics Committee of the Guangdong Provincial People's Hospital (No.2016232A).Results:The vessel density of SVC and DVC tended to decrease as the progression of DR.The vessel density of SVC was (51.25±3.27)%, (48.81±3.99)%, (47.00±3.49)%, (45.73±3.35)%, and the vessel density of DVC was (53.89±6.30)%, (49.94±6.05)%, (46.69±4.87)% and (44.78±4.30)% in the control group, NDR group, mild NPDR group, and moderate NPDR group, respectively.The vessel densities of SVC and DVC were statistically different among the four groups ( F=18.33, 21.53; both at P<0.01). The vessel density of SVC and DVC in the NDR group, mild NPDR group, moderate NPDR group was significantly lower than that in the control group (all at P<0.01). The vessel densities of FD300 in the mild NPDR group and moderate NPDR group were significantly lower than that in the control group (all at P<0.01). The FAZ area of the control group, NDR group, mild NPDR group, and moderate NPDR group was (0.31±0.11), (0.32±0.09), (0.34±0.13), and (0.37±0.10)mm 2, respectively.There was no significant difference in the FAZ area among the four groups ( F=2.18, P=0.09). The FAZ perimeter and AI were significantly higher in the moderate NPDR group than those in the control group (both at P<0.05). Conclusions:OCTA is able to detect the decrease of vessel density in diabetic patients before the occurrence of visible fundus lesions.The vessel density of SVC and DVC in patients with early stages of DR is decreased.DVC vessel density may be a sensitive marker to indicate DR.FD300 is not significantly decreased until mild NPDR, FAZ area and perimeter are significantly increased in moderate NPDR, indicating a more irregular FAZ.

Diabetic macular edema (DME) is the main cause of vision loss and even blindness in patients with diabetic retinopathy. Intravitreal anti-vascular endothelial factor therapy has become the gold standard management of DME. However, not all eyes response optimally to common management of DME, which could be due to the differences of individual factors. Increasing age could be the predictive factors for poor outcome. The influence of glycemic control, hypertension, dyslipidemia, chronic kidney disease and relative factors on treatment response require further investigation. Identifying the systemic factors that influence the treatment response of DME can provide the evidence to predict the prognosis of DME, and improve the efficacy of clinical treatment.

Objective:To analyze the distribution characteristics of peripheral retinopathy in Chinese patients with diabetic retinopathy (DR).Methods:A cross-sectional study. From January to December 2019, 265 cases of 388 eyes of DR patients diagnosed in the eye examination of Guangdong Provincial People's Hospital were included in the study. Among them, there were 211 eyes in 148 males and 177 eyes in 117 females; the average age was 58.4±12.3 years. Ultra-wide-angle fundus imaging (UWF) examination was performed by Daytona in Aalborg, UK. Use Photoshop to simulate the standard 7-azimuth (S7F) area, which was used as the central retinal area 1-7. The peripheral retinal areas 3-7 (P3-P7) were the adjacent peripheral retinal areas of the central retinal area 3-7, respectively. Divided DR into peripheral lesion predominant type (PPL) and central lesion predominant type (PCL). PPL was defined as at least one peripheral retinal area with more severe disease than its adjacent central area. χ 2 test was performed on the difference of PPL composition ratio in each retinal area of eyes with different DR stages. Results:Among 388 eyes, 200 eyes were PPL (51.5%, 200/388). Compared of PPL composition ratios of eyes with different stages of DR, mild non-proliferative DR (NPDR), moderate NPDR, severe NPDR and proliferative DR were 32 (36.8%, 32/87), 89 (55.3%, 89/161)), 42 (51.9%, 42/81), 37 (62.6%, 37/59), the difference was statistically significant ( χ2=11.440, P=0.010). Comparison of the distribution of PPL in each retinal area in DR eyes: in 200 PPL eyes, areas 3, 4, 5, 6, and 7 have 87, 101, 78, 67, and 38 eyes, respectively. The distribution of PPL in each retinal area in DR eyes was compared, and the difference was statistically significant ( χ2=37.640, P<0.001). Conclusions:PPL accounts for 51.5% of the eyes with DR. The DR stage are more severe, the proportion of PPL is higher. The temporal retinal peripheral lesions are the most common.