The Quantification Analysis Study Of Optical Coherence Tomography Angiography Parameters In Patients With Diabetic Retinopathy

Purpose:Using optical coherence tomography angiography(OCTA)to quantify the imaging parameters of patients with non-proliferative diabetic retinopathy(NPDR),and to investigate the correlation between retinal microstructural changes and macular edema.Methods:A retrospective study was used to collect 44 patients(44 eyes)with type 2diabetes(diabetic mellitus,DM)who were diagnosed with NPDR in the ophthalmology department of the First Affiliated Hospital of Nanchang University from June 2020 to December 2020.According to whether the above patients had macular edema,they were divided into the macular edema group(group I)and the non-macular edema group(group II),of which 22 subjects(22 eyes)were in the macular edema group and 22 subjects(22 eyes)were in the non-macular edema group.In addition,age and sex matched healthy volunteers 22 subjects(22 eyes)were included in the control group(group III).General information of the three groups of subjects was collected,including age,gender,duration of DM,BCVA,etc.OCTA examination was performed on the three groups of subjects to obtain macular VD,central macular thickness(CMT)and FAZ related indicators.The data of the three groups of research subjects were evaluated and analyzed by SPSS23.0 statistical analysis software.The correlation between VD and CMT,FAZ area and BCVA was studied by Pearson correlation and Spearman correlation analysis.Results:1.The VD of the superficial and deep macular area(except the fovea)of the macular edema group was lower than that of the non-macular edema group and the control group,respectively,with statistical difference(P<0.017).2.In the non-macular edema group,the VD of the superficial macular area(except the fovea)was lower than that of the control group,the VD of deep macular area(perifoveal-tempo,perifoveal-inferior)was lower than that of control group,with statistical difference(P<0.017).3.The FAZ area,perimeter and A-circularity index: the macular edema group was larger than the non-macular edema group and the control group,and the non-macular edema group was larger than the control group,the difference was statistically significant(P<0.017).FD-300: Both the macular edema group and the non-macular edema group were smaller than the control group,and the macular edema group was smaller than the non-macular edema group,the difference was statistically significant(P<0.017).4.In the macular edema group and the non-macular edema group,there was a negative correlation between the overall superficial macular VD and BCVA(LogMAR)(r=-0.778,P<0.05;r=-0.676,P<0.05).The VD value of the superficial fovea in the macular edema group was negatively correlated with BCVA(LogMAR)(r=-0.499,P<0.05).The superficial and deep fovea VD of the non-macular edema group were negatively correlated with the FAZ area(r=-0.625,P<0.05;r=-0.680,P<0.05).In the macular edema group,there was a positive correlation between FAZ area and BCVA(LogMAR)(r=0.567,P<0.05).Conclusions:1.The macular VD in NPDR patients decreased significantly,especially in patients with macular edema,suggesting the degree of macular ischemia is related to macular edema.2.The FAZ area increased in NPDR patients,especially in patients with macular edema,suggesting that the damage degree of microvascular structure in macular area was aggravated.3.The superficial VD of the macular area may serve as a marker to predict visual acuity in patients with diabetic macular edema.4.OCTA can quantify the blood perfusion in the macular area of DR patients and provide an effective means for early monitoring of DR.