| Objective: To observe the characteristics of macular vessel density(VD)in diabetic retinopathy(DR)using optical coherence tomography angiography(OCTA)and to investigate the influence of diabetes mellitus(DM)control in macular VD.Methods: A total of 84 T2 DM patients(84 eyes)and 37 healthy volunteers(37 eyes)were collected.According to the diagnostic criteria of DR,DM patients were divided into two case control studies: the non-diabetic retinopathy group(NDR group)included 49 patients(49 eyes).The mild non-proliferative diabetic retinopathy group(mild NPDR group)including 35 patients(35 eyes).Body mass index(BMI),fasting plasma glucose(FPG),glycosylated hemoglobin(Hb A1c),glycosylated albumin(GA),lipid metabolism,urinary microalbumin/creatinine ratio(ACR),carotid color Doppler ultrasound were tested,and the general clinical data such as gender,age,history of DM,insulin use,whether complicated with hypertension,diabetic peripheral neuropathy(DPN),carotid artery lesions were recorded.All subjects were scanned by OCTA with a range of 3mm*3mm in the macular area of the right eye,and quantitative analysis was performed in the superficial and deep VD of macular fovea and parafovea.Results:1.General clinical data: there was no statistical significance in age and gender among the three groups(P>0.05).In addition to the prevalence of DPN in the DM groups,there were no statistically significant differences in the prevalence of hypertension,carotid artery disease,insulin use,course of DM,BMI,FPG,Hb A1 c,GA,FPG,blood lipid and renal function in the NDR group and the mild NPDR group(P>0.05).Two groups were comparable.2.VD in macular: The deep VD in macular fovea,the superficial and deep VD in macular parafovea were statistically different among the three groups(P=0.019;0.009;<0.001 respectively)while no significant difference was found in the superficial VD of fovea(P>0.05).The DM patients were divided into two new subgroups according to their individual characteristics,complications and relevant indicators of DM control.Compared with the control group,there was no statistical difference in the superficial VD of macular fovea among the three groups(P> 0.05)while there was a statistical difference in the superficial and deep VD of macular parafovea(P <0.05).The deep VD of macular fovea showed statistically significant difference among the groups with and without carotid artery lesions and the control group(P< 0.042)and there was no significant difference among the remaining groups(P>0.05).3.Correlation analysis:(1)Point-biserial correlation analysis: the superficial VD of macular parafovea was positively correlated with hypertension group(rpb=0.244,P=0.025)and negatively correlated with DPN group(rpb=-0.278,P=0.01).There was a negative correlation between the deep VD of macular parafovea and carotid artery lesions(rpb=-0.244,P=0.025).(2)Spearman correlation analysis: the deep VD of macular parafovea was negatively correlated with the course of DM(rs=-0.264,P=0.015).The superficial VD of macula parafovea was negatively correlated with Hb A1 c and GA(Hb A1c:rs=-0.226,P=0.039;GA: rs=-0.223,P=0.042),and positively correlated with total cholesterol(TC)(rs=0.259,P=0.018).Conclusion: The significant reduction of the deep VD in macular fovea,the superficial and deep VD in macular parafovea may be the earliest change of retinal blood flow in DM patients.The retinal capillary lesions begin in macular parafovea and develop progressively to fovea.The loss of deep blood perfusion was earlier than superficial one.In addition,the superficial and deep VD in macular parafovea are correlated with DM risk factors such as the course of DM,the occurrence of complications and the comprehensive control level of DM.The retinal capillary damage detected by OCTA plays an important role in the early management and monitoring of DR. |
