视网膜血管形态改变与糖尿病、心脑血管疾病的关系

作为人体中小血管的重要组成部分,视网膜血管的形态如血管直径、形状、分布状态等可能会受到全身系统性疾病的影响.反之,作为人体惟一能直接窥探到的血管系统,视网膜血管形态的改变又能在一定程度上反映系统性血管疾病的发生、发展过程.采用数码眼底照相及其影像分析技术对视网膜血管形态进行定性和定量分析,寻找血管形态改变与糖尿病、心脑血管疾病之间的相互关系,并为相关系统性血管疾病(如糖尿病、高血压等)发生的危险性、严重程度以及发病机制提供参考.     

视网膜血管形态改变与糖尿病、心脑血管疾病的关系

作为人体中小血管的重要组成部分,视网膜血管的形态如血管直径、形状、分布状态等可能会受到全身系统性疾病的影响.反之,作为人体惟一能直接窥探到的血管系统,视网膜血管形态的改变又能在一定程度上反映系统性血管疾病的发生、发展过程.采用数码眼底照相及其影像分析技术对视网膜血管形态进行定性和定量分析,寻找血管形态改变与糖尿病、心脑血管疾病之间的相互关系,并为相关系统性血管疾病(如糖尿病、高血压等)发生的危险性、严重程度以及发病机制提供参考.     

环氧化酶-2抑制剂治疗眼部新生血管疾病实验研究进展

环氧化酶-2抑制剂曾广泛用于关节炎、镇痛、抗癌及预防心脑血管疾病等多个领域.近年来研究显示,它通过抑制白细胞介素以及多种血管生成因子而抑制血管生长,被实验用于治疗糖尿病视网膜病变、早产儿视网膜病变、脉络膜新生血管等新生血管疾病,但其临床应用效果、安全性有待进一步研究.     

阿司匹林与眼部新生血管的生成

阿司匹林是重要的非甾体抗炎药,通过抑制全身的环氧合酶发挥解热、镇痛、抗炎和抗血小板的作用,在心脑血管疾病及风湿免疫性疾病中被广泛使用.新生血管本是机体的一种自我修复,但同时在肿瘤及眼科各种疾病中也扮演着破坏者的角色.阿司匹林对病理性新生血管的产生到底发挥着何种作用,目前尚处于争论阶段:一方面,阿司匹林对于新生血管产生作用最强的作用因子血管内皮生长因子(VEGF)有一定的抑制作用;另一方面,阿司匹林又因抑制抗新生血管最强的因子,即内皮抑素生成,从而促进VEGF的生成.再者,阿司匹林对于眼部的血-视网膜屏障也有破坏作用,这在某种程度上也能造成眼底新生血管的生成.同时,我们分析了出现眼部新生血管的疾病中阿司匹林的作用.今后的研究中,阿司匹林在眼科领域与脉络膜新生血管生成中的关系急需得到进一步阐明,应综合衡量阿司匹林在新生血管防治中的利弊.     

小胶质细胞在视网膜血管发育及新生血管发生中的调控作用

小胶质细胞是中枢神经系统特化的组织巨噬细胞,对维持视网膜的正常形态和功能至关重要.近年研究提示,小胶质细胞在中枢血管系统建立之前已经移行进入大脑.除了具有调控炎症反应的免疫活性作用外,小胶质细胞在中枢神经系统发育期血管塑形以及病理状态下血管重塑中也发挥重要作用.小胶质细胞与生长期血管接触,促进出芽的血管融合;而且与血管内皮细胞存在双向的交互作用.在细胞间传递信息的外泌体以及Notch信号在这种交互作用中扮演重要角色.小胶质细胞在视网膜血管生成中的作用目前尚未得到重视,深入的基础研究有望为视网膜新生血管疾病的治疗提供帮助.本文就小胶质细胞的来源及其如何与血管内皮细胞进行交互作用,从而参与视网膜血管发育及新生血管的发生进行综述.     

视网膜动脉栓子的流行病学研究进展

视网膜动脉栓子在成人发病率较低,但视网膜动脉栓子的形成与颈动脉斑块及狭窄和多种心血管疾病相关。近年来的研究表明,视网膜动脉栓子可能提示脑卒中发作的危险性及致死率增高,是心血管因素之外的独立高危因素。因此,提高对视网膜动脉栓子的流行病学认识,及时进行全面的心脑血管检查评估,有助于及早发现、确诊和治疗心脑血管疾病,降低心脑血管疾病的致死率。     

视网膜微血管异常与心脑血管健康评估

要点 ·视网膜微血管异常包括视网膜微动脉瘤、出血、棉絮斑、硬性渗出、水肿等视网膜病变和视网膜动脉缩窄、动静脉交叉压迫征、动脉白鞘等视网膜血管改变 ·视网膜微血管异常的评价方法有定性、定量两种 ·视网膜微血管异常可出现于心脑血管疾病之前,并可能预测心脑血管疾病的发生、病程及预后 ·视网膜血管地形特征的描述将成为个体独立的心脑血管疾病危险性的评价标志     

Bevacizumab对眼表新生血管抑制作用的研究进展

目前,bevacizumab用于治疗眼内新生血管性疾病已取得了良好的临床疗效,如玻璃体注射治疗年龄相关性黄斑变性、虹膜新生血管、新生血管性青光眼、视网膜新生血管等疾病.随着研究的深入,一些研究者在眼表新生血管性疾病中应用该药,进行了动物实验和临床观察,取得了不同的疗效.本文就目前bevacizumab在治疗眼表新生血管性疾病,如:角膜化学伤、角膜穿通伤、角膜炎及角膜溃疡所形成的角膜新生血管、角膜移植手术形成的新生血管、翼状胬肉以及Stevens-Johnson综合征等新生血管相关性疾病中应用的相关研究进行综述.     

视网膜微血管异常与心脑血管疾病关系的流行病学研究

近年来人群为基础的流行病学调查,对眼底照片中视网膜微血管异常进行定性和定量评价,观察其与高血压病、脑卒中及冠心病等心脑血管疾病之间的关系。结果表明,视网膜微血管异常与心脑血管疾病的发生、发展以及预后密切相关;弥漫性视网膜动脉缩窄和动静脉交叉征是慢性高血压引起的血管损伤的标志;局限性动脉缩窄、视网膜出血、微动脉瘤和棉絮斑等则反映近期高血压病的严重程度;视网膜微血管异常可成为高血压病、脑卒中以及冠心病等发病及病程进展的预测因素。     

腺相关病毒载体介导视网膜疾病的基因治疗研究进展

视网膜疾病分子机制研究的不断深入,促进了视网膜疾病基因治疗的进展.腺相关病毒(AAV)的毒性和免疫原性均较低,外源基因表达稳定,可以转染多种分裂期和静止期细胞,因此成为治疗视网膜疾病的有效载体.在不同的动物模型和临床试验中,已有多项研究结果证实AAV作为载体治疗视网膜疾病的安全性和有效性.目前AAV在动物疾病模型中已经进行了介导抗血管生成蛋白、神经营养因子、抗凋亡因子的表达和基因替代治疗的研究,取得了令人满意的效果.但是,AAV也存在携带外源基因能力偏小的问题,需要进一步研究并解决之.     

Variation associated with measurement of retinal vessel diameters at different points in the pulse cycle

BACKGROUND/AIMS: To assess the variability in retinal vessel measurements at different points in the pulse cycle. METHODS: A healthy white male aged 19 years had 30 digitised images taken at three distinct points in the pulse cycle over a one hour period. A pulse synchronised ear clip trigger device was used to capture images at the desired point in the pulse cycle. Two trained graders measured the retinal vessel diameter of one large arteriole, one large venule, one small arteriole, and one small venule 10 times in each of these 30 images. RESULTS: Within an image, variability was similar between graders, pulse point, and vessel type. Across images taken at the same point in the pulse period, the change from the minimum to maximum measurement was between 6% and 17% for arterioles and between 2% and 11% for venules. In addition, measurements of small vessels had greater changes than large vessels and no point in the pulse period was more variable than another. Ignoring pulse cycle increased variability across images in the large venule, but not in the other vessel types. Mixed effect models were fit for each of the vessel types to determine the greatest source of variability. Controlling for pulse point and grader, the largest source of variability for all four vessels measured was across images, accounting for more than 50% of the total variability. CONCLUSION: Measurements of large retinal venules is generally less variable than measurements of other retinal vessels. After controlling for pulse point and grader, the largest source of variation is across images. Understanding the components of variability in measuring retinal vessels is important as these techniques are applied in epidemiological studies.     

Retinal vascular changes in congenital hypertrophy of the retinal pigment epithelium.

The overlying retinal blood vessels were abnormal in five cases of congenital hypertrophy of the retinal pigment epithelium. This illustrated the well-recognized association between outer retinal degeneration and obliteration of the overlying retinal vasculature. The proposed pathophysiological mechanisms, however, seem inadequate to explain completely the morphological changes of the retinal blood vessels in the presence of atrophy of the outer retina.     

Electroretinography and electro-oculography to localize abnormalities in early-stage inflammatory eye disease

Electrophysiological investigations were performed in patients with inflammatory eye disease characterized by the presence of vitreous cells. The eyes were classified into four categories on the basis of fluorescein angiography: 1) no fluorescein leakage from retinal vessels, 2) fluorescein leakage from peripheral retinal vessels, 3) fluorescein leakage from the disc or macular vessels, and 4) fluorescein leakage from retinal vessels associated with pigment epithelial and choroidal changes. The electro-oculogram light rise was abnormally increased in the eyes in category 1, but it progressively declined for those in the other categories. The ratio of the b-wave (postreceptoral component) and a-wave (receptoral component) of the flash electroretinogram was unchanged in all categories, but the electroretinographic amplitudes progressively declined from a somewhat supernormal level in category 1 to subnormal in the other categories. Thus, in inflammatory eye disease, changes in the electrical potentials arising in the pigment epithelium and photoreceptors are the earliest detectable signs. Some biochemical changes in the choroid, pigment epithelium, and the photoreceptors appear to take place before any pathological changes in these structures or in the retinal vessels are detectable by ophthalmoscopy or fluorescein angiography.     

视网膜脉络膜血管特征性改变作为系统性疾病生物标志物及其预警作用

    视网膜血管是人体血管系统中唯一可以在体直视的血管，其形态结构或功能的变化可直接或间接地反映一些全身疾病的情况。同样，一些全身疾病也会在视网膜血管上有特征性的表现。随着相干光断层扫描（optic coherent tomography，OCT）及OCT血管造影（OCT angiography，OCTA）等检查手段的发展，对脉络膜血管的认识也不断加深，发现既往一些眼部疾病与脉络膜血管的变化有紧密联系，也揭示出其与全身病的关系。视网膜和脉络膜血管的特征性改变如视网膜血管直径、走行、视网膜神经纤维层缺损、视网膜脉络膜血管密度等可能作为系统性疾病的生物标志物，在疾病的发病机制、预警、诊断和治疗反应评估中发挥作用。     

The changes of fluorescein angiography and visual electrophysiology in ocular posterior aging degeneration syndrome (OPADS).

Ocular posterior aging degeneration syndrome (OPADS) is related to age excepting inflammation, trauma, tumor, congenital abnormalities. Clinically, it can be divided into several types: degeneration, pre-retinal membrane, hole and mixed types. Changes can be seen in the choroidoretina with fluorescein angiography. In the degeneration type, there are changes of chroid-blood vessels, pigment epithelium and neovasculization. The manifestation in pre-retinal membrane type are small vascular tortuosity, expansion or fluorescein leadage, retinal pigment epithelium window defects. The hole type shows lack of retinal capillaries and retinal pigment epithelium window defects. Visual electrophysiological tests by various intensities and colors show the abnormal ERG. The bio-electricity active changes indicated the correlation among several ocular posterior aging degeneration types.     

眼底血管病理学改变特征研究

眼底血管是活体能唯一观察到的人体终末血管,许多疾病在眼底血管有病理改变,通过这些病理改变的研究,可以实现利用眼底血管改变诊断疾病,本文总结了眼底血管的部分常见病理学改变,以及引起这些改变的常见疾病,希望可以将部分疾病与眼底血管改变对应起来,以利于临床疾病的诊断。     

Morphological and immunohistochemical studies on degenerative changes of the retina and the optic nerve in neonatal rats injected with monosodium-L-glutamate

Degenerative changes in the retina and the optic nerve were investigated morphologically and immunohistochemically following administration of monosodium-L-glutamate (MSG) in rats. MSG (5mg/g b.w.) was injected subcutaneously every other day for 5 times after birth. The retina and the optic disc was observed ophthalmoscopically at 1, 3 and 6 months after birth. At the same stage, morphological and immunohistochemical changes were also investigated under light microscopy. The neuron of the retinal ganglion cell was identified immunohistochemically with antiserum to neurofilament 200 kD (NF). Glial cells were stained with antisera to glial fibrillary acidic protein (GFAP) and S-100 beta protein, and myelin of oligodendrocytes was also stained with antiserum to myelin basic protein (MBP). Histologically the inner layer of the retina was selectively destroyed, and the optic nerve also showed degeneration, changing into a thin strand. The retinal vessels were narrow and coarse, however, they extended to the peripheral region. Although immunohistochemical staining with NF antiserum was scarcely detected both in the retina and in the optic nerve, glial stainings with GFAP and S-100 beta protein antisera were widely observed in the perivascular space of the retina and in the glial column of the optic nerve. These findings indicated that the ganglion cells and their neurons are significantly affected by MSG, but the retinal vessels and glial cells are rarely affected. Ophthalmoscopically, the optic discs of rats treated with MSG were small and deeply excavated. The vitreous vessels persisted in most cases even at 6th months after birth.(ABSTRACT TRUNCATED AT 250 WORDS)     

Study of the method to measure the diameter of retinal vessels

PURPOSE: To estimate the objective and repeatable method for measurements of the retinal vessels' diameter. The direct reason for creating this method was to use it to evaluate the influence of exogenous estrogens on the retinal blood vessels. MATERIAL AND METHODS: Based on modern computer systems, using funduscamera Canon NF 505, the model of active matrix for repeatable method for estimating the changes in vessels' diameter, was elaborated. RESULTS: After statistical analysis of a material of 3000 measurements, the degree of objectiveness and recurrence and the potential scale for errors was acknowledged. This method enables the estimation of the changes in retinal vessels diameter caused by many different factors in comparison to initial observations (set as 100%) in every analysed case. CONCLUSIONS: Presented method can be successfully used for objective, reliable evaluation of changes in the blood vessels diameter caused by many different factors.     

The width of the light reflex on retinal arteries and veins

A computerized microdensitometric technique was applied to fundus photographs of 40 young male subjects. The width of the blood column and the width of the central light reflex were measured on 240 arteries and 240 veins of various sizes. No light streaks were registered on vessels of caliber less than 50 micron. The ratio of the widths: light streak/blood column showed wider reflexes on small (less than 100 micron) compared to larger (greater than or equal to 100 micron) vessels in both arteries and veins (P less than 0.01). Small retinal veins had wider light streaks than small arteries (P less than 0.01). The results of these objective measurements are partly in conflict with previous ophthalmoscopic observations, and we challenge accepted views on clinical interpretation on reflectivity differences in normal retinal vessels. Our results are discussed on a background of hemodynamics of microcirculatory flow.     

Photocoagulation in selected cases of pathology of retinal vessels]

The authors presented methods and results of treatment by means of an argon laser of 12 patients with pathological changes of the retinal vessels. Diagnosed in these patients were: capillary haemangioma (Hippel-Lindau disease), teleangiectasis and macroaneurysms of the retinal vessels. Photocoagulation by argon laser of these vascular changes in these patients in right time showed to be a favourable therapeutic method, especially when the changes are localized in the posterior pole of the eye.