糖尿病视网膜病变中视网膜内皮细胞功能障碍的研究进展

视网膜内皮细胞(REC)是参与糖尿病视网膜病变和许多眼部疾病的主要细胞类型之一。视网膜微血管系统有助于血-视网膜屏障的维持,这对正常的视功能至关重要。REC的改变在视网膜疾病的发生发展中起着关键作用。高血糖是糖尿病微血管损伤的重要原因,通过不同的机制导致REC功能障碍,包括向衰老表型改变、迁移和增殖能力增强、炎性凋亡等,最终导致无细胞毛细血管及病理性新生血管形成。本文对糖尿病视网膜病变中REC的功能障碍作一综述。     

OCTA测量参数在眼部疾病诊疗中的应用

光学相干断层扫描血管成像(optical coherence tomography angiography, OCTA)是一种用于眼部血管成像的新技术, 现已广泛应用于视网膜、脉络膜以及视神经的血管成像。它既可以提供视网膜血管的形态信息, 又可以提供眼底血管密度的定量测量。OCTA测量参数包括黄斑区视网膜浅层毛细血管网(superficial capillary plexus, SCP)密度、视网膜深层毛细血管网(deep capillary plexus, DCP)密度以及黄斑中心凹无血管区(foveal avascular zone, FAZ)面积等。视网膜微血管系统是维持视功能的重要基础, 视网膜血管密度是衡量视网膜微血管循环状态的指标。黄斑区SCP密度、DCP密度以及FAZ面积与许多眼部疾病的发生发展有关, 如视网膜阻塞性疾病、黄斑裂孔、糖尿病性视网膜病变、高度近视、中心性浆液性脉络膜视网膜病变以及年龄相关性黄斑变性等。应用OCTA观察眼底血流的早期改变以及探讨相关眼部疾病的发病机制、疗效评估具有重要的临床意义。(国际眼科纵览, 2022, 46:11-16)     

结膜微循环测量的影像学研究

微循环是指微动脉、微静脉和毛细血管间的微血管循环和淋巴循环,是循环系统的中心环节。微血管的形态测定和定量分析以及动态微循环异常在理解疾病病理生理学以及微血管病变治疗中发挥着重要作用。球结膜微循环与眼科多种疾病息息相关。目前主要通过光学显微镜及电子显微镜、激光扫描共聚焦显微镜、相干光断层扫描血管造影、视网膜功能成像仪、正交偏振光谱成像和功能裂隙灯生物显微镜等影像学方法对结膜微血管进行测定和分析。（国际眼科纵览, 2018,  42:   199-203）     

如何发挥眼保健在心脑血管疾病防治中的作用?

眼底视网膜检查为非侵入性、直接观察系统性微血管改变的唯一途径，国外多项流行病调查及队列研究证实，视网膜微血管改变及其视网膜病变为预测心脑血管疾病的发生、发展、治疗效果及预后提供了重要的临床指标。对社区人群采用数码眼底照相的筛查模式，不仅能对可预防盲的眼病（青光眼、糖尿病视网膜病变）进行筛查，而且结合高血压、高血糖、高血脂，检测视网膜微血管改变，对心脑血管疾病进行预测。此筛查模式费用低、效率高，受到社区医院欢迎，具有推广前景。     

糖基化终产物对纯化培养大鼠视网膜神经节细胞凋亡的影响

糖尿病性视网膜病变是糖尿病患者严重的眼部并发症，其病因和发病机制尚未阐明。近年来人们认为慢性高血糖引起体内糖基化蛋白的过量沉积，形成糖基化终产物，从而导致各系统的慢性疾病和功能丧失。传统上人们多认为糖尿病性视网膜病变主要是微血管病变，包括：内皮细胞增殖、基底膜增厚、周细胞丧失等。但目前许多临床研究表明：在糖尿病性视网膜病变微血管病变发生以前，糖尿病患者已有视功能改变。动物实验发现在糖尿病早期，     

视网膜动静脉管径与系统性危险因素

微循环是无法直接观察和研究调查。视网膜提供了评估微循环非侵入性方法。目前,量化视网膜微血管变化的可靠方法存在。尤其,通过定量测量视网膜血管口径,提高了对视网膜动脉和小静脉口径和系统性因素的影响和临床意义的认识,大量研究证实AV,RV和AVR变化可能反映亚临床脑血管、心血管疾病和新陈代谢异常的临床前期改变。     

视网膜血管管径测量及其应用进展

视网膜血管管径测量可以采用无创手段来进行,而肯眼部和全身多种疾病邯会对视网膜血管管径造成不同程度的影响.近年来,计算机辅助的视网膜图像分析技术日臻完善,可以对多种眼部疾病和全身疾病在视网膜血管管径上的改变进行评估.与此同时,通过视网膜血管管径改变预测某些眼病及系统性疾病的发生风险,这些疾病在临床诊断前视网膜血管已经有变化了.视网膜血管管径测量对全身疾病的预测作用将是其最大的应用和研究价值所在.     

糖尿病眼病与甲皱微循环改变的相互关系

糖尿病眼病与甲皱微循环改变的相互关系武汉市洪山广州军区武汉总医院眼科马群，黄震唏武汉市洪山广州军区武汉总医院微循环室刘洪糖尿病常可引起视网膜病变，其眼底表现为微血管瘤，出血斑、渗出班和增殖性视网膜病变等，眼底微小血管病变是全身微血管病变的缩影，甲皱微...     

光相干断层扫描血管成像对青光眼视网膜微循环的评估

视网膜的微循环改变与青光眼密切相关。光相干断层扫描血管成像(OCTA)是一种无创检查, 可同时提供视网膜以及其血管信息, 对视网膜各层微循环的检测效果良好, 近年被运用到青光眼的研究和监测中。放射状盘周毛细血管(RPC)密度与视网膜神经纤维层厚度呈正相关, 因而在青光眼评估中尤为重要。OCTA对视网膜微循环改变的评估主要在视盘旁区和黄斑区。青光眼患者视盘旁区全层和RPC血管密度显著下降, 其与视网膜神经纤维层厚度变薄以及视野缺损均匹配, 并与疾病严重程度相关;黄斑区则呈现血管密度下降, 无血管区面积显著增大的趋势。对比不同类型和阶段的青光眼, 晚期青光眼以及正常眼压性青光眼的OCTA改变更显著。OCTA结果可受到高度近视和眼压变化的影响, 视盘旁区的OCTA改变对青光眼的诊断价值更高。总体来看, OCTA可以为青光眼视网膜微循环评估提供新的技术手段。本文从视网膜微循环的OCTA表现以及青光眼视网膜微循环的OCTA图像改变, 包括青光眼视盘旁区微循环OCTA改变、黄斑区微循环OCTA改变、OCTA评估青光眼黄斑区与视盘旁区微循环的影响因素及诊断价值比较几个方面就OCTA对青光眼视网膜微循...     

从视网膜氧化应激与微血管改变谈糖尿病视网膜病变的发病机制和防治策略

糖尿病视网膜病变（DR）是糖尿病患者因长期高血糖而并发的视网膜微循环障碍性眼病，随病情进展可致严重视力损害。DR作为一种病因复杂的多因素疾病，尽管发病机制尚未完全阐明，但氧化应激已被证明是其中一个关键因素。高血糖引起机体多种代谢异常相互作用，诱导视网膜活性氧过度产生、氧化应激损伤增加，导致视网膜线粒体功能障碍、微血管功能障碍、血-视网膜屏障破坏、新生血管形成等一系列病理反应，显著影响DR发生发展的各个阶段。深入研究视网膜氧化应激与微血管改变在DR发病机制中的作用将有助于为防治DR提供新的思路。     

Retinal microvascular abnormalities and their relationship with hypertension, cardiovascular disease, and mortality

Retinal microvascular abnormalities, such as generalized and focal arteriolar narrowing, arteriovenous nicking and retinopathy, reflect cumulative vascular damage from hypertension, aging, and other processes. Epidemiological studies indicate that these abnormalities can be observed in 2-15% of the nondiabetic general population and are strongly and consistently associated with elevated blood pressure. Generalized arteriolar narrowing and arteriovenous nicking also appear to be irreversible long-term markers of hypertension, related not only to current but past blood pressure levels as well. There are data supporting an association between retinal microvascular abnormalities and stroke, but there is no convincing evidence of an independent or direct association with atherosclerosis, ischemic heart disease, or cardiovascular mortality. New computer-related imaging methods are currently being developed to detect the presence and severity of retinal arteriolar narrowing and other microvascular characteristics. When reliably quantified, retinal microvascular abnormalities may be useful as risk indicators for cerebrovascular diseases.     

Vaskuläre Netzhauterkrankungen als Spiegel generalisierter Gefäßveränderungen

Retinal vascular diseases are mostly caused by systemic vascular diseases. In some cases the systemic disease is already known but in other patients ocular anomalies often provide the first indications of a systemic disease. Treating patients with vascular fundus diseases requires close cooperation between ophthalmologists and specialists in other fields and deciding which routine and specialized diagnostic examinations are necessary in light of the potential risk factors involved requires interdisciplinary communication. This article aims to provide an overview of the most important vascular retinal diseases and which examinations are required to ensure an accurate diagnosis. The retinal vascular diseases with the highest frequency or clinical relevance are hypertensive retinopathy, diabetic retinopathy, retinal vein occlusion and retinal artery occlusion.     

Review of the association between retinal microvascular characteristics and eye disease

Computerized retinal imaging technologies enable the static and dynamic measurement of a range of retinal microvascular parameters. Large population‐based studies have reported associations between these microvascular indices and various ophthalmic diseases including diabetes, age‐related macular degeneration, retinal artery embolism, retinal vein occlusion, glaucoma and non‐glaucomatous optic neuropathies. Increasingly, sophisticated imaging and analysis techniques have the potential to provide relevant clinical information regarding disease risk and progression; however, further studies are required to verify associations and strengthen the predictive power of these techniques. We summarize the current state of knowledge regarding retinal microvascular characteristics and eye disease.     

Peripheral retinal neovascularization in talc retinopathy.

BACKGROUND: Neovascularization of the peripheral retina can be present in a number of systemic and ocular diseases. Very rarely, peripheral retinal neovascularization can also be manifested in intravenous drug abusers. In addition to ocular complications, intravenous drug abusers are at high risk for contracting various infections and the development of pulmonary and cardiovascular diseases. We present a case of a chronic heroin and cocaine abuser with bilateral peripheral retinal neovascularization, pulmonary complications, and a history of endocarditis. CASE REPORT: A patient with a 20-year history of heroin and cocaine abuse initially presented for a routine eye examination. Fundus examination revealed pinpoint white deposits centered in both maculas, engorged vascular fronds with a patch of intraretinal hemorrhage in the peripheral retinal of the right eye and neovascularization of the disc as well as exudation with adjacent focal preretinal hemorrhage in the left eye. The patient underwent fluorescein angiography and was screened for diabetes, sarcoidosis, and sickle cell disease. When no systemic disease could be discovered, it was concluded that the peripheral retinal neovascularization developed as a result of vascular occlusion from heroin and cocaine abuse. DISCUSSION: It is important to investigate the cause of neovascularization in the peripheral retina. Retinal vascular emboli such as talc are common in drug abusers, but in most cases, the retinal deposits pose only a minimal threat to vision. However, this case shows that careful retinal examination is warranted in drug abusers to rule out neovascularization of the retina. Other causes of peripheral retinal neovascularization should be ruled out as well. These conditions include sickle cell retinopathy, sarcoidosis, diabetic retinopathy, blood dyscrasias, retinal vascular occlusion, Eales' disease, and other systemic conditions, so that appropriate ocular and systemic treatment can be provided. Peripheral retinal neovascularization is best treated by pan-retinal photocoagulation.     

Systemic associations of retinal microvascular signs: a review of recent population-based studies

Retinal microvascular signs, such as generalized retinal arteriolar narrowing, focal arteriolar narrowing, arteriovenous nicking and retinal haemorrhages, microaneurysms and cotton wool spots, are common fundus findings in the general population, even in individuals without hypertension or diabetes. Recent population-based studies have provided new insights into the systemic associations and clinical significance of these retinal signs. Studies show that these retinal microvascular signs are strongly associated with elevated blood pressure (BP). Generalized retinal arteriolar narrowing may be associated with markers of inflammation and risk of diabetes and hypertension. Retinal haemorrhages, microaneurysms and cotton wool spots are associated with risk of subclinical and clinical stroke, cognitive impairment, renal dysfunction and cardiovascular mortality, independent of BP and cardiovascular risk factors. A consistent pattern of association between retinal microvascular signs and ischaemic heart disease has not been demonstrated. This suggests that patients with some retinopathy signs (retinal haemorrhages, microaneurysms and cotton wool spots) may benefit from a careful systemic evaluation and, if supported by further research, appropriate risk reduction therapy.     

Choroidal and retinal thickness in systemic autoimmune and inflammatory diseases: A review

To identify the risk of relapse and subclinical inflammatory stages of systemic autoimmune diseases, new tools are needed. In the recent years, choroidal thickness and retinal thickness measured with ocular coherence tomography (OCT) have been proposed as an inflammatory marker for different systemic diseases, especially for conditions with a vascular component. Our aim in this article is to review the literature regarding the role of choroidal and retinal thickness as a potential inflammatory marker in systemic autoimmune and inflammatory diseases measured by OCT. Current literature suggests that the choroid of patients thickens in active phases of inflammatory diseases with vascular involvement. This pattern is observed in lupus, systemic sclerosis, Behçet disease, spondylitis, and familial Mediterranean fever. Choroidal thickness may decrease with biological treatments, along with systemic inflammation. Repeated flares and long-term disease, however, may thin the choroid, as a result of prolonged insult to the microvasculature and subsequent atrophy. Less is known about the effect of these diseases on retinal thickness. In summary, choroidal and retinal thickness measured by OCT may be promising markers for inflammation in systemic autoimmune and inflammatory diseases; however, more studies are warranted before generalizing choroidal thickness measurements by OCT as a marker for disease activity. The role of retinal thickness is more unclear due to a lack of studies in this field.     

Assessment of flow dynamics in retinal and choroidal microcirculation

Alterations in ocular blood flow have been implicated in mechanisms that lead to vision loss in patients with various ocular disorders such as diabetic retinopathy, glaucoma, and age-related macular degeneration. Assessment of retinal and choroidal blood flow is also a window to evaluate systemic diseases that affect microvasculature. Quantification and qualification of the blood flow in the retina and choroid help us understand pathophysiology, stratify disease risk, and monitor disease progression in these disorders. Multiple methods are used by researchers for assessment of blood flow, but a gold standard is lacking. We review commonly used methods, both invasive and noninvasive, for evaluation of blood flow, including intravital microscopy, laser Doppler velocimetry, laser Doppler flowmetry, laser interferometry, confocal scanning laser Doppler flowmetry, laser speckle flowgraphy, Doppler optical coherence tomography, blue-field entoptic simulation, retinal vessel caliber assessment, optical coherence tomography angiography, retinal function imaging, color Doppler imaging, and scanning laser ophthalmoscope angiogram. As technology evolves, better evaluation of blood flow in various ocular and systemic diseases will likely bring new perspectives into clinical practice and translate to better diagnosis and treatment.     

Systemic diseases associated with various types of retinal vein occlusion

PURPOSE: To investigate systemic diseases associated with various types of retinal vein occlusion. METHODS: We investigated prospectively in 1090 consecutive patients with retinal vein occlusion, almost all Caucasian (consistent with the racial pattern here), the prevalence of associated systemic disorders before or at the onset of various types of retinal vein occlusion. The patients were categorized into six types of retinal vein occlusion based on defined criteria: nonischemic and ischemic central retinal vein occlusion, nonischemic and ischemic hemi-central retinal vein occlusion, and major and macular branch retinal vein occlusion. The patients had a detailed ophthalmic and systemic evaluation according to our protocol. For data analysis, patients were divided into three age groups: young (younger than 45 years), middle-aged (45 to 64 years), and elderly (65 years or older). The observed prevalence rates of major systemic diseases were compared among central retinal vein occlusion, hemi-central retinal vein occlusion, and branch retinal vein occlusion using a polytomous logistic regression analysis adjusting for gender and age. Logistic regression adjusting for age and gender was also used to compare the observed prevalence of systemic disease between nonischemic and ischemic in central retinal vein occlusion and hemi-central retinal vein occlusion and between major and macular branch retinal vein occlusion. These observed prevalence rates were also compared with those expected in a gender-matched and age-matched control population from estimates from the US National Center for Health Statistics. RESULTS: There was a significantly higher prevalence of arterial hypertension in branch retinal vein occlusion compared with central retinal vein occlusion (P < .0001) and hemi-central retinal vein occlusion (P = .028). Branch retinal vein occlusion also had a significantly higher prevalence of peripheral vascular disease (P = .0002), venous disease (P = .011), peptic ulcer (P = .031), and other gastrointestinal disease (P < .0001) compared with central retinal vein occlusion. The proportion of patients with branch retinal vein occlusion with cerebrovascular disease was also significantly (P = .049) greater than that of the combined group of patients with central retinal vein occlusion and patients with hemi-central retinal vein occlusion. There was no significant difference in prevalence of any systemic disease between central retinal vein occlusion and hemi-central retinal vein occlusion. A significantly greater prevalence of arterial hypertension (P = .025) and diabetes mellitus (P = .011) was present in the ischemic central retinal vein occlusion compared with the nonischemic central retinal vein occlusion. Similarly, arterial hypertension (P = .0002) and ischemic heart disease (P = .048) were more prevalent in major branch retinal vein occlusion than in macular branch retinal vein occlusion. Relative to the US white control population, the combined group of patients with central retinal vein occlusion and patients with hemi-central retinal vein occlusion had a higher prevalence of arterial hypertension (P < .0001), peptic ulcer (P < .0001), diabetes mellitus (in ischemic type only, P < .0001), and thyroid disorder (P < .0001). The patients with branch retinal vein occlusion showed a greater prevalence of arterial hypertension (P < or = .005), cerebrovascular disease (P = .007), chronic obstructive pulmonary disease (P = .012), peptic ulcer (P < .0001), diabetes (in young only, P = .0005), and thyroid disorder (P = .003) compared with the US white control population. CONCLUSIONS: The findings of our study revealed that a variety of systemic disorders may be present in association with different types of retinal vein occlusion and in different age groups, and that their relative prevalence differs significantly, so that the common practice of generalizing about these disorders for the entire group of patients with retinal vein occlusion can be misleading. The presence of a particular associated systemic disease does not necessarily imply a cause-and-effect relationship with that type of retinal vein occlusion; the particular disease may or may not be one of the risk factors in a multifactorial scenario predisposing an eye to develop a particular type of retinal vein occlusion. Based on our study, we think that apart from a routine medical evaluation, an extensive and expensive workup for systemic diseases is unwarranted in the vast majority of patients with retinal vein occlusion.