Application Of OCTA In Diabetic Retinopathy

Objective:This topic research is Optical Coherence Tomography vascular imaging(Optical Coherence Tomography Angiography,OCTA)in diabetic patients with microvascular structure change in the process of measuring parameters,analyze the influencing factors of DR progress and installment of the relationship between diabetic retinopathy,using the OCTA technology inspection on patients with diabetic retinopathy,analysis of diabetic retinopathy retinal microvascular morphology of every period and microcirculation,blood flow to the study of the parameters of the OCTA characteristics in the different stages of DR,From the occurrence of clinically visible fundus lesions in diabetic patients to the retinal proliferation stage,the relationship between each parameter measured quantitatively by OCTA and each stage of DR was analyzed to provide basis for the early diagnosis and staging of DR.methods:In this study,diabetic patients were diagnosed as diabetic by endocrinologist according to blood glucose level,and underwent ophthalmologic examination and hematological specimen examination.Ophthalmic examination includes best corrected visual acuity(BCVA)obtained by optometry,intraocular pressure,slit lamp microscopy,20D and 90D indirect fundus examination,fundus photography,OCT and OCTA examination;Blood pressure,weight and height;Blood tests included glycosylated hemoglobin,liver and kidney function,blood lipid analysis and blood glucose,etc.After ophthalmologist's diagnosis and staging of diabetic retinopathy according to my DR clinical diagnosis and treatment guidelines(2014).A total of 307 350 eyes were included,including 280 eyes in diabetic patients(245)and 70 eyes in healthy control group(62).Ophthalmologists to study fundus is divided into four periods:DR?phase of the group of 69 eyes(60),DR?phase of the group of 68 eyes(62 people),DR?phase of the group of 71 eyes(62)and DR?phase of the group of 72 eyes(61 people).This research based on adopts the Heidelberg Spectralis OCTA machine(model:Spectralis OCT2)for Germany Heidelberg company,machine comes with program and analysis software(version:HEYEXV6.7),the machine according to the results of the inspection OCTA microvascular automatic analysis of the image,the macular area scanning range is 3 mm*3 mm,scanning signal strength index>50,longitudinal and transverse scan scanning each need 3s.Analysis of test results,DR periods in the macular area of shallow and deep center concave without perfusion area(foveal avascular zone,FAZ)shape,size,DR periods in the macular area of shallow and deep within the scope of 3mm*3 mm microvascular density(vessels density,VD)size,analysis the influence factors of affecting DR progress and microcirculation in the macular area inner link between structure and function characteristics,compared to healthy people in the macular area circulation structure and function characteristics,for the DR provide objective basis for early diagnosis and clinical staging.Results:There were no statistically significant differences in age,sex,body mass index(calculated according to height and weight),course of disease,fasting blood glucose or groups between the control group and the DR group(P>0.05).With the development of DR,OCTA images showed that the FAZ area increased gradually with the aggravation of the disease,while THE VD decreased gradually,and the non-perfusion area appeared(P<0.05).Hb A1c and FPG were also gradually aggravated(P<0.05).Liver and kidney function were positively correlated with blood lipid analysis(P<0.05).Statistical analysis showed that the FAZ area of the control group was different from that of the diabetes group and between the diabetes groups,and the difference was statistically significant(P<0.05).Compared with the control group was(0.342±0.037mm~2),in the shallow retinal microvascular,DR?period group(0.458±0.047mm~2),DR?period group(0.461±0.039mm~2),DR?period group(0.466±0.042mm~2)and DR?period group(0.471±0.012mm~2)greater FAZ area(P<0.05).In deep retinal microvascular networks,DR?period group(0.656±0.042mm~2,P<0.05),DR?group(0.687±0.051mm~2,P<0.05),DR?period group(0.728±0.057mm~2,P<0.05)and DR?period group(0.741±0.059mm~2,P<0.05)were compared with the control group(0.451±0.065 mm~2)FAZ area value are increased.Compared with the control group(2.302±0.506 mm),the average circumference of FAZ in(SCP),Dr stage I group(2.703±0.596 mm),Dr stage II Group(2.690±0.482 mm),Dr stage III group(2.780±0.306mm)and Dr stage IV group(2.830±0.716 mm)had longer average circumference of FAZ(P<0.05).In SCP,the AI values of FAZ in Dr stage I group(1.252±0.127,),Dr stage II Group(1.121±0.106,),Dr stage III group(1.209±0.427,)and Dr stage IV group(1.121±0.713,)were higher than those in control group(1.105±0.072),and the differences were statistically significant(P<0.05).The MVD of SCP was 0.596±0.032 in control group,0.521±0.046 in Dr stage I group,0.509±0.031 in Dr stage II group,0.489±0.049 in Dr stage III group and 0.481±0.066 in Dr stage IV group,Compared with the control group,the MVD of Dr stage?and Dr?groups was lower than that of control group(P<0.05);The mean value of blood flow density in the macular area of DCP was 0.631±0.061 in control group,0.548±0.072 in Dr stage I group,0.496±0.076 in Dr stage II group,0.461±0.082 in Dr stage III group and 0.419±0.081 in Dr stage IV group.The MVD of control group was lower than that of control group(P<0.05).With the progress of Dr disease,Hb Alc and FPG also increased gradually(P<0.05);liver and kidney function and blood lipid analysis were positively correlated(P<0.05).With the progression of DR disease,there were statistically significant differences in microvascular VD in almost all areas of the superficial and deep retina of macular area in diabetes groups compared with the control group(P<0.05).Spearman rank correlation test analyzed the correlation between FAZ area and the severity of VD and DR.The results showed that there was little correlation between the severity of FAZ area in the shallow layer and that there was a significant positive correlation between FAZ area in the deep layer and the severity of disease(Deep layer:r=0.46,P<0.05),and VD area in the deep layer:r=0.53,P<0.05).Deep layer:R=0.59,P<0.05)was negatively correlated with the severity of DR.DR progression increased,FAZ area increased,and VD decreased.Similarly USES Spearman rank correlation test analysis of Hb A1c,FPG,liver and kidney function,blood lipids,course of the disease and diabetic retinopathy in the macular area microvascular VD,the relevance of the results suggest:Hb A1c,FPG,liver and kidney function,blood lipids,course of the disease and diabetic retinopathy in the macular area microvascular VD is negatively related to Hb A1c(r=0.48,P<0.05),the FPG(r=0.62,P<0.05),which increased with the increase of Hb A1c values and levels of FPG,diabetic retinopathy,macular area smaller capillaries of VD.Conclusion:Among all OCTA parameters,the further back DR classification is,the more serious the damage of FAZ is in the shallow and deep retina of macular area,and the normal morphology is lost.The larger the FAZ area is.The smaller the VD in the shallow and deep retina of macular area,the worse the microcirculation blood perfusion in macular area,and the worse the function of visual cells in macular area.The changes of Hb A1c,FPG,liver and kidney function,blood lipid and course of disease were correlated with the changes of microvascular VD in macular area of diabetic retinopathy.Among them,VD of deep retinal microvessels was highly sensitive to the changes of microvessels in macular area in patients with diabetes mellitus.OCTA images and parameters can provide objective basis for the early diagnosis and staging of DR.