Study On The Changes Of Microvasculature In Different Stages And Different TCM Syndrome Types Of DR By SS-OCTA

Objective: To study the changes of microvasculature in different stages and different traditional Chinese medicine(TCM)syndrome types of diabetic retinopathy(DR)by swept-source optical coherence tomography angiography(SS-OCTA).It provides a theoretical basis for the diagnosis and treatment of diabetic ophthalmopathy,and provides a theoretical basis for further study on the pathophysiological mechanism of Type 2 diabetes mellitus.Methods: In this prospective study,healthy control subjects and DR subjects were included.DR subjects were divided into stages and TCM syndrome differentiation.The stages were non-proliferative diabetic retinopathy(NPDR)group and proliferative diabetic retinopathy(PDR)group.TCM syndrome types are deficiency of both Qi and Yin accompanied with collaterals stasis syndrome,liver and kidney deficiency producing Qi-blood insufficiency of ocular collaterals syndrome,Yin and Yang deficiency combined with blood stasis and phlegm coagulation syndrome.The retinal and choroidal data of all subjects were collected by SS-OCTA,including ultra-wide field(UWF)vessel density(VD)and perfusion density(PD)of deep and superficial vascular complexes.Finally,statistical analysis was carried out to observe the changes of retinal and choroidal microvasculature in different stages and different traditional Chinese medicine(TCM)syndrome types of DR,and analyze the correlation between each index and different stages and different TCM syndrome types of DR.Results: In the distribution of TCM syndrome types of patients with NPDR and PDR,deficiency of both Qi and Yin accompanied with collaterals stasis syndrome account for 60.98% and 46.43% respectively,followed by liver and kidney deficiency producing Qi-blood insufficiency of ocular collaterals syndrome account for 31.71% and 36.90% respectively.Yin and Yang deficiency combined with blood stasis and phlegm coagulation syndrome account for 7.31%and 16.67% respectively.When analyzing the differences of clinical characteristics of patients with DR in different stages,it was found that compared with the healthy control group,the area,perimeter and acircularity index(AI)of foveal avascular zone(FAZ)in the NPDR group and PDR group were significantly increased,and the fractal dimension at 300μm area beside FAZ(FD300)was significantly decreased(P≤0.001).In the circular areas with different radii at the center of the macular fovea,the retinal thickness increased significantly(P≤0.001),while the VD,PD of deep and superficial vascular complexes,choroidal perfusion(CP)and choroidal vascularity index(CVI)decreased in different degrees(P ≤ 0.05).When analyzing the differences of clinical characteristics of DR patients with different TCM syndrome types,it was found that the UWF VD of deep and superficial vascular complexes with Yin and Yang deficiency combined with blood stasis and phlegm coagulation syndrome was the lowest.The choroidal thickness of patients with deficiency of both Qi and Yin accompanied with collaterals stasis syndrome was lower than that of patients with liver and kidney deficiency producing Qi-blood insufficiency of ocular collaterals syndrome,and higher than that of patients with Yin and Yang deficiency combined with blood stasis and phlegm coagulation syndrome(P≤0.05).In the correlation analysis between each index and DR in different stages,we found that the duration of T2 DM,UWF VD of deep vascular complex,UWF PD of deep vascular complex,perimeter of FAZ were all significantly correlated with the grouping((r = 0.856 to-0.575,P<0.001).And in the correlation analysis between each index and DR in different TCM syndrome types,we found that the UWF VD of deep vascular complex,UWF PD of deep vascular complex,BCVA were all significantly correlated with the grouping(r =-0.684 to-0.516,P<0.001).Conclusion: In the distribution of TCM syndrome types of patients with DR,the number of patients with deficiency of both Qi and Yin accompanied with collaterals stasis syndrome is the largest,followed by deficiency of liver and kidney deficiency producing Qi-blood insufficiency of ocular collaterals syndrome,and deficiency of Yin and Yang deficiency combined with blood stasis and phlegm coagulation syndrome is the least.There are also significant differences in FAZ and retinal blood flow in DR with different stages or different TCM syndrome types,especially in UWF VD and PD of deep vascular complexes,CP and CVI.Furthermore,SS-OCTA is a non-invasive,economical and convenient examination in evaluating the retinal choroidal microvasculature in patients with different stages or different TCM syndrome types of DR,providing highly detailed quantitative information about the wider retinal microvasculature.In order to have a positive impact on the quality of life of patients with diabetic retinopathy,the changes of retinal and choroidal microvasculature should be discovered as soon as possible,and accurate grading and preventive treatment should be carried out.UWF VD and PD of deep vascular complexes may be remarkable and non-invasive biomarkers evaluating stages and differentiating TCM syndrome types of DR.