Automated evaluation of parapapillary choroidal microvasculature in crowded optic discs:a controlled,optical coherence tomography angiography study

AIM:To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography(OCT-A).METHODS:Thirty patients with crowded discs,and 47 control subjects were enrolled in the study.One eye of each individual was included and OCT-A scans of optic discs were obtained in a 4.5×4.5 mm^(2) rectangular area.Radial peripapillary capillary(RPC)density,peripapillary retinal nerve fiber layer(pRNFL)thickness,cup volume,rim area,disc area,cup-to-disc(c/d)area ratio,and vertical c/d ratio were obtained automatically using device software.Automated parapapillary choroidal microvasculature(PPCMv)density was calculated using MATLAB software.When the vertical c/d ratio of the optic disc was absent or small cup,it was considered as a crowded disc.RESULTS:The mean signal strength index of OCT-A images was similar between the crowded discs and control eyes(P=0.740).There was no difference in pRNFL between the two groups(P=0.102).There were no differences in RPC density in whole image(P=0.826)and peripapillary region(P=0.923),but inside disc RPC density was higher in crowded optic discs(P=0.003).The PPCMv density in the inner-hemisuperior region was also lower in crowded discs(P=0.026).The pRNFL thickness was positively correlated with peripapillary RPC density(r=0.498,P<0.001).The inside disc RPC density was negatively correlated with c/d area ratio(r=-0.341,P=0.002).CONCLUSION:The higher inside disc RPC density and lower inner-hemisuperior PPCMv density are found in eyes with crowded optic discs.

Effects of obstructive sleep apnea on retinal microvasculature

AIM:To detect retinal microvascular variations in obstructive sleep apnea syndrome patients.METHODS:This prospective,observational case-control study included healthy controls and patients with mild,moderate,and severe obstructive sleep apnea syndrome.Vascular parameters,foveal avascular area,and flow areas in macula-centered,6.00×6.00 mm2 scan size optical coherence tomography angiography images were compared.RESULTS:The control group had the highest whole image,parafoveal,and perifoveal vessel density among the groups in both superficial and the deep capillary plexus(all P<0.05).Rapid eye movement sleep apnoea-hypopnoea index was reversely correlated with whole(Rho=-0.195,P=0.034),parafoveal(Rho=-0.242,P=0.008),perifoveal(Rho=-0.187,P=0.045)vessel density in the superficial capillary plexus,and whole(Rho=-0.186,P=0.046),parafoveal(Rho=-0.260,P=0.004),perifoveal(Rho=-0.189,P=0.043)vessel density in the deep capillary plexus,though the mean and non-rapid eye movement sleep apnoeahypopnoea index related with only parafoveal vessel density in the superficial capillary plexus(Rho=-0.213,P=0.020;Rho=-0.191,P=0.038)and the deep capillary plexus(Rho=-0.254,P=0.005;Rho=-0.194,P=0.035).CONCLUSION:This study shows decreased vessel density and its reverse correlation with the apnoea-hypopnoea index in patients with obstructive sleep apnea syndrome.

Increased retinal venule diameter as a prognostic indicator for recurrent cerebrovascular events:a prospective observational study

Microvasculature of the retina is considered an alternative marker of cerebral vascular risk in healthy populations.However,the ability of retinal vasculature changes,specifically focusing on retinal vessel diameter,to predict the recurrence of cerebrovascular events in patients with ischemic stroke has not been determined comprehensively.While previous studies have shown a link between retinal vessel diameter and recurrent cerebrovascular events,they have not incorporated this information into a predictive model.Therefore,this study aimed to investigate the relationship between retinal vessel diameter and subsequent cerebrovascular events in patients with acute ischemic stroke.Additionally,we sought to establish a predictive model by combining retinal veessel diameter with traditional risk factors.We performed a prospective observational study of 141 patients with acute ischemic stroke who were admitted to the First Affiliated Hospital of Jinan University.All of these patients underwent digital retinal imaging within 72 hours of admission and were followed up for 3 years.We found that,after adjusting for related risk factors,patients with acute ischemic stroke with mean arteriolar diameter within 0.5-1.0 disc diameters of the disc margin(MAD_(0.5-1.0DD))of≥74.14μm and mean venular diameter within 0.5-1.0 disc diameters of the disc margin(MVD_(0.5-1.0DD))of≥83.91μm tended to experience recurrent cerebrovascular events.We established three multivariate Cox proportional hazard regression models:model 1 included traditional risk factors,model 2 added MAD_(0.5-1.0DD)to model 1,and model 3 added MVD0.5-1.0DD to model 1.Model 3 had the greatest potential to predict subsequent cerebrovascular events,followed by model 2,and finally model 1.These findings indicate that combining retinal venular or arteriolar diameter with traditional risk factors could improve the prediction of recurrent cerebrovascular events in patients with acute ischemic stroke,and that retinal imaging could be a useful and non-invasive method for identifying high-risk patients who require closer monitoring and more aggressive management.

Development and Innovation of Modern Microvascular Anastomoses

High-quality microvascular anastomosis is the foundation of successful microsurgery and one of the most important basic skills for microsurgeons. The traditional manual suture is recognized as the “gold standard” for microvascular anastomosis, but it still has problems such as long operation time and easy to cause vascular damage. In order to improve the success rate of microvascular anastomosis, reduce surgical complications and make the prognosis of patients better. In order to improve the success rate of microvascular anastomosis and reduce the surgical complications, scholars at home and abroad have developed some new vascular anastomosis techniques that are simple, fast and minimally invasive while improving the traditional surgical suturing methods. In this paper, we review the microvascular anastomosis, and its application research in two methods of traditional hand suture and non-suture anastomosis, in order to promote the application development of microvascular anastomosis.

OCTA评估高血压对无糖尿病视网膜病变2型糖尿病患者视网膜微血管的影响

目的通过光学相干断层扫描血管成像(OCTA)评估高血压(HTN)对无糖尿病视网膜病变(DR)2型糖尿病(T2DM)患者视网膜微血管的影响。方法选取2023年3月—2024年3月就诊于徐州医科大学附属医院内分泌科及心血管内科的无DR的T2DM患者,共154例154眼。根据T2DM是否合并高血压以及合并高血压的严重程度分为:T2DM组(n=47)、T2DM合并轻中度HTN组(n=55)、T2DM合并重度HTN组(n=52)。应用OCTA对视网膜黄斑区行血流成像扫描,分析各组患者视网膜黄斑区各参数指标的变化。结果与T2DM组相比,其他2组6 mm×6 mm视网膜黄斑区的旁中心凹区域浅层毛细血管丛(SCP)密度各象限均降低(P<0.05),黄斑中心凹周围区域颞侧、上方SCP密度降低(P<0.05);黄斑旁中心凹区域颞侧、上方、鼻侧,黄斑中心凹周围区域颞侧、上方深部毛细血管丛(DCP)密度降低(P<0.05);与合并轻中度HTN组相比,合并重度HTN组视网膜黄斑区的旁中心凹区域SCP密度各象限均降低(P<0.05),黄斑中心凹周围区域颞侧、上方SCP密度降低(P<0.05);黄斑旁中心凹区域颞侧、上方、鼻侧,黄斑中心凹周围区域颞侧、上方DCP密度降低(P<0.05)。与T2DM组相比,其他2组患者黄斑中心凹无血管区(FAZ)面积及周长增大,FD-300减小(P<0.05);与合并轻中度HTN组相比,合并重度HTN组FAZ面积及周长增大,FD-300减小(P<0.05)。结论OCTA检查发现无DR改变的T2DM患者合并高血压时,视网膜黄斑区微血管损伤更严重,且血压越高,损害越重。OCTA对合并高血压T2DM患者的检查、诊断、随访有重要的临床应用价值。

在体全眼微血流超声超分辨成像

多类眼科疾病的早期阶段一般伴有血管的形态学和血流动力学改变,因此,全眼微血管评估对眼科疾病的综合诊断具有重要作用。由于光学成像技术的穿透深度有限,特别是在介质透光率低的情况下,现有的光学成像技术难以对整个眼睛的微血管进行可视化。为此,该文开发了一种超声超分辨成像技术,可以微米级分辨率可视化全眼三维微血管系统。首先,用中心频率为10 MHz的线性阵列快速采集多帧序列;其次,经过微泡信号提取,中心点定位,追踪和中心点叠加得到一个剖面的超分辨率图像;最后,将机械扫描的所有剖面重建为兔全眼三维超分辨率微血管图像。实验结果证明,超声定位显微镜可以显示整个眼睛的微血管系统,这对眼科疾病的早期诊断具有重要意义。

Characteristics of macular microvasculature before and after idiopathic macular hole surgery

AIM:To evaluate the macular microvasculature before and after surgery for idiopathic macular hole(MH)and the association of preoperative vascular parameters with postoperative recovery of visual acuity and configuration.METHODS:Twenty eyes from 20 patients with idiopathic MH were enrolled.Optical coherence tomography angiography(OCTA)images were obtained before,2 wk,1,and 3 mo after vitrectomy with internal limiting membrane peeling.Preoperative foveal avascular zone(FAZ)area and perimeter and regional vessel density(VD)in both layers were compared according to the 3-month best-corrected visual acuity(BCVA).RESULTS:The BCVA improved from 0.98±0.59(log MAR,Snellen 20/200)preoperatively to 0.30±0.25(Snellen 20/40)at 3 mo postoperatively.The preoperative deep VD was smaller and the FAZ perimeter was larger in the 3-month BCVA<20/32 group(all P<0.05).A significant reduction was observed in FAZ parameters and all VDs 2 wk postoperatively.Except for deep perifoveal VD,all VDs recovered only to their preoperative values.The postoperative FAZ parameters were lower during follow-up.Decreases in preoperative deep VDs were correlated with worse postoperative BCVA(Pearson’s r=-0.667 and-0.619,respectively).A larger FAZ perimeter(Spearman’s r=-0.524)and a lower deep perifoveal VD preoperatively(Pearson’s r=0.486)were associated with lower healing stage.CONCLUSION:The status of the deep vasculature may be an indicator of visual acuity in patients with a closed MH.Except for the deep perifoveal region,VD recovers only to preoperative levels.

Microvasculature of the esophagus and gastroesophageal junction: Lesson learned from submucosal endoscopy

Advanced therapeutic endoscopy,in particular endoscopic mucosal resection,endoscopic submucosal dissection,per-oral endoscopic myotomy,submucosal endoscopic tumor resection opened a new era where direct esophageal visualization is possible.Combining these information with advanced diagnostic endoscopy,the esophagus is organized,from the luminal side to outside,into five layers(epithelium,lamina propria with lamina muscularis mucosa,submucosa,muscle layer,adventitia).A specific vascular system belonging to each layer is thus visible: Mucosa with the intra papillary capillary loop in the epithelium and the sub-epithelial capillary network in the lamina propria and,at the lower esophageal sphincter(LES) level with the palisade vessels; submucosa with the drainage vessels and the spindle veins at LES level; muscle layer with the perforating vessels; periesophageal veins in adventitia.These structures are particularly important to define endoscopic landmark for the gastro-esophageal junction,helpful in performing submucosal therapeutic endoscopy.

Decreased retinal microvasculature densities in pterygium

AIM:To investigate the retinal vascular network alterations in eyes of patients with pterygium.METHODS:Totally 18 left eyes from 18 female pterygium patients and 18 left eyes from 18 female healthy control subjects were enrolled.Optical coherence tomography angiography(OCTA)images were generated of the superficial retinal layer and deeper retinal layer of the macular retina for each eye.The microvascular(MIR)and macrovascular(MAR)densities were calculated and MIR,MAR,and total microvascular(TMI)density was compared in the healthy control and pterygium groups.RESULTS:In pterygium group,in the superficial retinal layer,the vascular density in superficial MIR,superior right(SR),inferior right(IR),right(R),superficial central annuli(SC)1,SC2,and SC3 decreased significantly in the macular area(P<0.05).Furthermore,the vascular density in all those decreased regions except R,was significantly and negatively correlated with the disease course(r=-0.6038 to-0.7762,P=0.0008),and the area size of pterygium(r=-0.6043 to-0.9508,P<0.05).For the deeper retinal layer,the density of deep total microvessel(DTMI),deeper MIR,SR,IR,R,DC2,and DC3 decreased significantly in macular area of pterygium patients(P<0.05).Furthermore,the vascular density in all those decreased regions was significantly and negatively correlated with the disease course(r=-0.6901 to-0.7795,P=0.0015),and the area size of pterygium(r=-0.6043 to-0.9563,P<0.05).No statistically significant differences and correlation was found in other region density(|r|<0.47,P>0.05).CONCLUSION:OCTA findings suggest that pterygium patients present with decreased retinal MIR density,and the major vascular alterations occurr mainly on the bitamporal side.The vascular density of the superficial SC1,SC2,SC3 adjacent to the foveal and deep layer of DC2,DC2 regions,significantly decreased.

Antioxidant-induced reductive stress has untoward consequences on the brain microvasculature

All cells in the body metabolize oxygen in a series of reactions in the mitochondria to generate energy.A by-product of these reactions is the production of highly reactive oxygen radicals which have the potential to cause irreparable damage to cellular components,and have been linked to mutagenic and neurotoxicity of the nervous system.Under normal conditions,innate molecular systems,glutathione,superoxide dismutases,

High-speed high-resolution laser diode-based photoacoustic microscopy for in vivo microvasculature imaging

Laser diodes(LDs)have been considered as cost-effective and compact excitation sources to overcome the requirement of costly and bulky pulsed laser sources that are commonly used in photoacoustic microscopy(PAM).However,the spatial resolution and/or imaging speed of previously reported LD-based PAM systems have not been optimized simultaneously.In this paper,we developed a high-speed and high-resolution LD-based PAM system using a continuous wave LD,operating at a pulsed mode,with a repetition rate of 30 kHz,as an excitation source.A hybrid scanning mechanism that synchronizes a one-dimensional galvanometer mirror and a two-dimensional motorized stage is applied to achieve a fast imaging capability without signal averaging due to the high signal-to-noise ratio.By optimizing the optical system,a high lateral resolution of 4.8μm has been achieved.In vivo microvasculature imaging of a mouse ear has been demonstrated to show the high performance of our LD-based PAM system.

基于近红外漫射光技术的脑血流断层成像研究

目的脑部微血管血流动力学参数对于很多疾病的诊断和评估具有重要意义,为实现人体脑部微血管血流无创、低成本的空间影像重建,研发近红外漫射光相关断层成像(Near-Infrared Diffuse Light Correlation Tomography,DCT)技术,用于组织血流的三维成像。方法采用Bregman-TV算法求解DCT中待重构的病态方程组,选取10名健康受试者进行头上位倾斜(Head-Up-Tilting,HUT)脑部血流成像实验,诱发受试者脑部血流发生变化,分析受试者在平躺以及倾斜至70°两种状态下的脑血流变化。结果HUT实验结果表明,受试者在平躺时脑部血流较大,当倾斜床向上倾斜至70°状态时,受试者血流影像显示其脑部血流降低,实验结果与理论相符。结论本研究中的DCT系统可以将患者的脑部血流状况直观、快速地呈现给医生,具有较高的临床应用价值。

口腔黏膜下纤维化的细胞及分子机制的研究进展

口腔黏膜下纤维化(oral submucous fibrosis, OSF)是口腔黏膜在持续的慢性损伤中形成异常修复的病理过程。其特征是炎性反应、大量细胞外基质沉积及血管丢失,最终导致口腔黏膜的结构及功能损伤。炎症细胞的浸润是口腔黏膜下纤维化的导火索,提示局部组织的免疫微环境在其发生、发展中起重要作用。激活的肌成纤维细胞可分泌大量的细胞外基质,它们重新组装、重塑,从而抵抗胶原酶降解,而血管的丢失可明显加重纤维化的进展。本文就口腔黏膜下纤维化的病因及局部组织免疫环境失调、细胞外基质的沉积及血管的丢失对口腔黏膜下纤维化进展中的影响作一综述。

Advances in cellular and molecular mechanisms of oral submucosal fibrosis

Oral submucosal fibrosis(OSF)is a pathological process in which the oral mucosa forms abnormal repair in persistent chronic injury.It is characterized by inflammatory reactions,massive extracellular matrix deposition and vascular loss,ultimately leading to structural and functional damage of the oral mucosa.The infiltration of inflammatory cells is the fuse of oral submucosal fibrosis,suggesting that the immune microenvironment of local tissues plays an important role in its occurrence and development.Activated myofibroblasts can secrete large amounts of extracellular matrix,which reassemble and remodel,thereby resisting collagenase degradation,while the loss of blood vessels can significantly aggravate the progression of fibrosis.This article reviews the etiology of oral submucosal fibrosis and the effects of local tissue immune environment imbalance,extracellular matrix deposition and vascular loss on the progression of oral submucosal fibrosis.

眼结膜微血管数据管理系统设计与实现

眼结膜微血管数据的有效管理直接影响相关临床研究的成果和效率。现有的眼结膜微血管数据由于缺乏安全规范的数据管理系统,严重制约了眼结膜微血管数据的相关临床研究发展。文章基于LabVIEW软件和Access数据库,自主设计一套眼结膜微血管数据管理系统。系统经过临床研究技术员评价,显示该系统界面友好清晰,操作便捷,运行稳定。系统实现了数据的安全有效规范管理,为眼结膜微血管数据管理提供了稳定可靠的解决方案。

原发性肝癌肿瘤新生血管形态特征与其DSA血供分型关系的研究

目的 探讨原发性肝癌肿瘤新生血管形态特征与其DSA血供分型的关系。方法 收集1988年 1月～ 2 0 0 2年 2月间 ,我们两所医院手术切除前曾行血管造影且未做栓塞治疗的原发性肝癌标本 32例。血管造影至手术切除时间为 13～ 70d ,平均 (31.9± 19.1)d。肿瘤直径为 2～ 2 3cm ,平均 (8.0 5± 6 .17)cm。对其DSA血供分型、肿瘤新生血管密度 (MVD)计数、肿瘤新生血管分型、肿瘤新生血管直径测量、梁索直径测量 ,并对观察指标做相关统计学分析。结果 ①肝癌DSA血供与肿瘤新生血管分型呈正相关趋势 ;②MVD在乏血供组低于中等血供、富血供组 ;③新生血管直径、新生血管梁索直径比呈随HCC造影血供增加而增大的趋势。结论 ①肝癌肿瘤MVD、形态及分布不均匀 ;②肝癌在生长的不同阶段 ,其肿瘤新生血管特征是不同的 ,并有一定的发展规律 ;

无三叉神经痛者三叉神经与血管关系:3D FSPGR序列

目的 利用 3DFSPGR序列研究无三叉神经痛受检者中三叉神经脑池段与邻近血管关系。资料与方法回顾性分析 5 0例无三叉神经痛患者增强轴位 3DFSPGR图像 ,层厚 1mm ,分别观察双侧三叉神经周围是否存在血管影 ,同时测定三叉神经长轴与邻近血管的距离 ,根据神经周围血管有无及距离的远近分成无血管、远离、接近、接触、变形 5种情况。结果 5 0例患者 10 0侧三叉神经中 ,周围无血管的三叉神经占 37% (右侧 18例 ,左侧 19例 ) ,其中 12例双侧三叉神经周围皆无血管。在周围有血管的三叉神经中 ,接触占 2 3% ,接近占 11% ,远离占 2 9%。所有研究对象中皆未发现血管引起的三叉神经变形。结论 3DFSPGR序列可用于三叉神经和邻近血管关系的研究。在无三叉神经痛者三叉神经与微血管接触率为 2 3% 。

心肌梗死前心绞痛对再灌注治疗后心肌微血管功能的影响

目的 :探讨心肌梗死前心绞痛对再灌注治疗后心肌微血管功能的影响 ,从心肌微循环灌注角度阐明梗死前心绞痛的意义。 方法 :2 4例急性心肌梗死病人分为有梗死前心绞痛 (AP)组 (AP组 ,13例 )和无梗死前心绞痛组 (无AP组 ,11例 )。所有病人在症状开始后 6小时内接受经皮冠状动脉腔内成形术及支架置入术 ,术后 12小时内行静脉心肌声学造影 ;监测心肌酶谱变化。 结果 :两组病人基本临床情况无显著差异 (P >0 0 5 )。有AP组与无AP组肌酸激酶峰值分别为 1880± 2 60U/L、2 3 5 7± 3 81U/L (P <0 0 1) ,肌酸激酶MB同工酶峰值分别为 3 84± 5 4U/L、 5 3 1± 5 7U /L (P <0 0 1) ;室壁运动积分分别为 1 0 1± 1 0 4、 1 2 3± 0 44 (P <0 0 5 ) ,左心室射血分数分别为 0 61± 0 13、 0 43± 0 11(P <0 0 1) ;心肌声学造影积分分别为 1 2 3± 0 44、 1 91± 1 0 4(P <0 0 5 ) ,标化A×B值分别为 0 81± 0 2 3、 0 46± 0 3 5 (P <0 0 1) ,均有显著性差异。 结论 :有微血管损伤的急性心肌梗死病人 ,其心肌损伤严重 ,心功能较差 ;梗死前心绞痛通过预适应效应限制心肌损伤 ,有利于心肌存活、心功能恢复及心肌微血管完整性的保存。因而 ,梗死前心绞痛不仅对心肌有保护作用 。

三叉神经痛:MRI序列选择及MRI诊断价值

目的 探讨三叉神经痛患者的MRI影像表现及最佳成像序列和方法 ,评价MRI对三叉神经痛的诊断价值。资料与方法 应用三维稳态构成干扰序列 (constructiveinterferenceinsteadystate ,CISS)和三维稳态旋进快速成像序列 (fastimagingwithsteadystateprecession ,FISP)结合三维预磁化快速梯度回波序列 (magnetizationpreparedrapidgradientechoimaging ,MPRAGEor3D MPR) ,并采用三维多平面或曲面重建技术对 2 5例 (5 0条 )正常对照组及 5 0例(5 0条 ,单发 )三叉神经痛患者行MR成像 ,观察MRI图像中神经、血管显示情况和三叉神经痛在MRI中的表现形式。结果 (1)正常对照组神经血管压迫或接触为 30 % ,三叉神经痛患者病侧为 96 % ,血管包绕神经及神经变形 ,对照组没有出现 ,病例组 5例。 (2 ) 5 0例三叉神经痛患者中病侧MRI诊断为血管压迫或接触的为 38例 ,手术证实有血管压迫为 18例 ,另有 10例行γ 刀治疗 ,术后症状消失 ;桥小脑角肿瘤 7例 ,均为手术证实 ;血管病变 5例 ,均由微血管减压术或手术证实。 (3)正常对照组与病例组神经血管压迫或接触的阳性率差异有显著意义 (P <0 .0 0 5 ) ,诊断敏感性为 96 % ,特异性为 79%。结论 磁共振 3D CISS和 3D FISP序列结合 3D

红腹锦鸡和小白鼠肾小球微血管铸型的扫描电镜观察

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