ABSTRACT
@#Diabetic retinopathy and diabetic nephropathy are the two most common and serious microvascular complications in diabetic patients, and they are the main causes of blindness and end-stage renal disease. Retinal blood vessels are the common damage targets of early diabetes and the only living blood vessels in the human vascular system that can be directly observed in naked eye. The changes in their morphological structure or function directly or indirectly reflect the microvascular lesions caused by diabetes. Especially, in recent years, the development of optical coherence tomography angiography(OCTA), a new and non-invasive technology, has made its breakthroughs in angiography resolution, vascular depth and vascular morphology, and it can provide objective quantitative data. It has certain application value in diabetic microangiopathy. Therefore, the purpose of this paper is to review OCTA and its application in diabetic microangiopathy.
ABSTRACT
@#AIM: To investigate the differences of the choroidal vascularity index between type 2 diabetes with diabetic retinopathy and non-diabetes patients.<p>METHODS: A retrospective cross-sectional study was performed at Beijing Friendship Hospital. Enhanced depth imaging spectral-domain optical coherence tomography(EDI-OCT)scans of 68 eyes of 68 type 2 diabetes who with diabetic retinopathy were compared with those of right eyes of 34 age- and gender-matched healthy controls. The choroidal images were binarized into luminal areas(LA)and stromal areas(SA). CVI was defined as the ratio of LA to total circumscribed subfoveal choroidal area. Mean choroidal thickness, mean retinal thickness and mean CVI between patients and controls were compared using <i>t</i>-test. <p>RESULTS: There were no significant differences in total circumscribed subfoveal choroidal area(0.53±0.14mm2 <i>vs</i> 0.49±0.15mm2), LA(0.35±0.09mm2 <i>vs</i> 0.32±0.10mm2), SA(0.17±0.05mm2 <i>vs</i> 0.17±0.06mm2), or subfoveal choroidal thickness(347.9±76.9μm <i>vs</i> 325.9±92.9μm)between patients with DR and controls(<i>P</i>>0.05). However, there was a significantly lower CVI in patients with diabetes as compared to controls(64.33%±3.25% <i>vs</i> 67.04%±2.46%, <i>P</i><0.001). The critical value was 63.59%.<p>CONCLUSION: CVI is a kind of biological indicators which can directly reflect the changes of choroidal internal structure, and it is more stable and reliable than SFCT. For type 2 diabetic patients who with diabetic retinopathy, CVI is lower than that of healthy people.
ABSTRACT
· AlM: To observe the characteristic of choroidal circulation in diabetics and investigate its changes as well as the relationship between it and the development and progression of diabetic retinopathy ( DR) . ·METHODS:All 45 diabetics were divided into 3 groups:no diabetic retinopathy ( NDR), nonproliferative diabetic retinopathy ( NPDR ) , proliferative diabetic retinopathy ( PDR);and 20 health people were selected to be control group.All subjects were examined by FFA and indocyaine green angiography ( lCGA ) ( Heidelberg retina tomography, Germany ) at the same time. The characteristics of angiograph results were comparatively observed and the feature of diabetic choroidapathy were analyzed. · RESULTS: ( 1 ) There were no significant differences between DR groups and control group in the central retinal artery ( CRA ) filling time.There were significant decreases of the choroidal artery filling time in DR groups, compared to the control group (P ·CONCLUSlON:lCGA may be a useful adjunct to FFA in the evaluation of choroidal vascular changes in DR.The research provides that the diabetic choroidal circulation was abnormal before the occurrence of DR, which fully proved the presence of diabetic choroidopathy.
ABSTRACT
AlM: To investigate the relationship between the subfoveal choroidal thickness ( SFCT) and both choroidal hemodynamic index and glycosylated hemoglobin in diabetic subjects.METHODS:Seventy-eight type 2 diabetic patients (156 eyes) from ophthalmology and endocrinology ward of our hospital were enrolled in this study, including 39 females and 39 males, with a mean age of (59. 8±6. 2)years. According to early treatment diabetic retinopathy study ( ETDRS) grading method, all samples were divided into diabetic retinopathy ( DR ) group, mild or moderate nonproliferative diabetic retinopathy group, severe nonproliferative diabetic retinopathy ( NPDR) group and proliferative diabetic retinopathy ( PDR ) group. The SFCT and choroidal hemodynamic index were measured by enhanced depth imaging optical coherence tomography ( EDl-OCT ) and Color Doppler lmaging. Recording glycosylated hemoglobin content of all samples. Using multivariate linear regression to analyse the relationship between the SFCT and both choroidal hemodynamic index and glycosylated hemoglobin.RESULTS: The end diastolic velocity ( EDV ) was significant higher and the SFCT was significant thinner in no diabetic retinopathy ( NDR) group than other groups. There was no significant difference of peak systolic velocity ( PSV ) between four groups. The resistance index ( Rl) was significant higher in severe NPDR group than NDR group and mild or moderate group, the Rl in PDR group was hihgest than other group with statistically significance. The SFCT was correlated positively ( b =0. 540,P<0. 001) with the glycosylated hemoglobin. No significant correlation was found between the SFCT and the choroidal hemodynamic index (DR,P=0. 341;PSV,P=0. 770;EDV,P=0. 131;Rl,P=0. 084).CONCLUSlON: Our results suggest that there is no significant correlations between the SFCT and the choroidal hemodynamic index; glycosylated hemoglobin is one of the factors that affect the SFCT in diabetic patients.
ABSTRACT
Objective To investigate the expression time and the position of VEGF in the choroid of diabetic rats and compare them with the VEGF expression in the choroid and retina of normal rats.Methods Healthy male Wistar rats were selected and randomly divided into diabetic group and normal group.Type 1 diabetes rat model was induced by being injected of large-dose streptozotocinum(STZ) into abdominal cavity.The retina and choroid of rats were obtained to detect the VEGF expression by immunohistochemistry at 1~(st),2~(nd),3~(rd),4~(th),5~(th) month after diabetes induction.Results VEGF expression in retina and choroid of rats was of obvious difference between normal group and one-month diabetic group.In two-month diabetic group,VEGF expression in choroid was positive(33.3%),while VEGF expression in retina was not significantly different with that of normal group.In three-month diabetic group,VEGF expression in choroid was positive(55.6%),and VEGF expression in inner nuclear layer and ganglion cell layer of retina was positive(33.3%).In four-month diabetic group,VEGF expression in choroid was positive(66.7%),and VEGF expression in inner limiting membrane,inner nuclear layer,outer nuclear layer and ganglion cell layer of retina was positive(77.8%).In five-month diabetic group,VEGF expression in choroid was positive(88.9%),and VEGF expression in the whole retina was positive(88.9%).The expression density of VEGF in choroid and retina gradually increased((P