基因芯片技术及其在视网膜疾病中的应用

21世纪是生命科学的世纪,也是一个信息爆炸的时代。2002年6月26日首张人类基因图和测序计划(HGP)完成后;科学家们开始进入功能基因组,即“后基因时代”的研究。随蛋白组学研究与疾病相关基因和功能蛋白不断发现,出现了大量的生物信息和需要解决的医学问题。随之,现代生物技术,转入基因组学技术、蛋白组学技术、生物信息学、生物芯片技术、基因克隆、重组、表达技术,动物体细胞克隆技术等方面,其中引人关注的是生物芯片技术,生物芯片技术始于20世纪80年代后期,被评为1998年度世界十大科技进展之一,其概念源于计算机芯片。其成熟标志为全球…     

小儿视网膜电图检查技术的探讨

通过对１６００多例小儿进行ＥＲＧ检查，总结了小儿ＥＲＧ检查过程中操作要点及注意事项。讨论了口服镇静剂熟睡状态下与氯胺酮基础麻醉下查小儿ＥＲＧ的优缺点。本工作为国内小儿ＥＲＧ检查提供了有效的参考方法。     

基因芯片技术及其在视网膜疾病中的应用

21世纪是生命科学的世纪，也是一个信息爆炸的时代。2002年6月26日首张人类基因图和测序计划（HGP）完成后；科学家们开始进入功能基因组即“后基因时代”的研究。随蛋白组学研究与疾病相关基因和功能蛋白不断发现，出现了大量的生物信息和需要解决的医学问题。随之，现代生物技术转入基因组学技术、蛋白组学技术、生物信息学、生物芯片技术、基因克隆、重组、表达技术，动物体细胞克隆技术等方面，其中引人关注的是生物芯片技术。生物芯片技术始于20世纪80年代后期，被评为1998年度世界十大科技进展之一，其概念源于计算机芯片，其成熟标志为全球掀起至今方兴未艾的技术研究和产业化年产的热潮。     

RNA干扰技术在视网膜疾病治疗中的研究进展

RNA干扰(RNA interference,RNAi)是一种在动物中广泛存在的、通过双链RNA分子在mRNA水平上诱导特异性序列基因沉默的过程。作为一种阻断基因表达的新手段,RNAi技术日趋成熟完善,开辟了一条基因治疗的新途径。RNAi技术能够有效阻止视网膜新生血管的形成,抑制增生性玻璃体视网膜病变的发生和发展,诱导视网膜母细胞瘤细胞的凋亡。现将RNAi技术在上述视网膜病变中的研究进展作一综述。     

视觉电生理检查在糖尿病视网膜病变前期诊断中的应用

糖尿病视网膜病变(DRP)是糖尿病常见的严重并发症之一,也是主要的致盲性眼病之一,如能在糖尿病视网膜病变发生之前,早期诊治,有效的控制血糖及改善视网膜的微循环,就可以减少DRP的发生或减慢其进程,笔者于2001年8月～2004年5月对58例(116只眼)未发生眼底病变的DM确诊患者进行OPs及PVEP检查,现报告如下：     

视网膜电图在研究高海拔视网膜病变中的应用

随着高原经济的发展和高原人群活动的日渐频繁,高原相关疾病成为了社会和医学的关注焦点,亦成为了制约高原发展的重要因素.高海拔视网膜病变(high altitude retinopathy,HAR)作为高原相关疾病的一种,主要表现为视网膜血管的充血、迂曲,以及视网膜出血、玻璃体腔出血.HAR早期效应可表现为短暂的视功能障碍,长期效应则为视力不可逆损伤和眼部并发症.HAR重在预防,早期诊断并及时治疗,预后较好.视觉电生理学检查技术以其独特的优势在眼科疾病的诊断鉴别、预后判定、疗效评价等方面具有重要作用.视网膜电图(electroretinogram,ERG)是视觉电生理检查中的重要组成部分,作为视网膜功能的一种客观的检查方法,应用于高海拔视网膜病变的检查中,不仅可以评估在高海拔下视网膜的功能的变化,早期发现还未出现临床表现的HAR,还可动态观察HAR的发展及治疗效果.     

多焦视网膜电图在视网膜疾病中的应用

多焦视网膜电图通过互相关技术可以同时记录视网膜不同局域的视网膜电反应信号,继而可以显现视网膜中央40°～50°的功能地形图,其优势在于:能够在较短的时间内提供客观的中心视网膜功能评估地形图.为此,本文基于当前的文献报道,对多焦视网膜电图在常见的后天获得性视网膜疾病中的临床应用进行综述.     

RNA interference targeting NOX4 protects visual function in an experimental model of retinal detachment by alleviating blood-retinal barrier damage

AIM:To observe the effects of the inhibition of NADPH oxidase 4(NOX4)expression on the retinal vascular barriers and visual function after retinal detachment(RD).METHODS:RD model was established 3 wk after adenoassocianed virus vector injection.The retinal tissue was harvested 3 d after RD,and the death of retinal vascular endothelial cells and photoreceptors was observed using electron microscopy.The NOX4 expression was detected by Western blot.Confocal microscopy was used to observe a retinal patch that had been perfused with Evans blue.A modified water maze test was used to detect the time required to find the platform on the water surface.The visual function of the rats was evaluated and reactive oxygen species(ROS)expression was detected by a fluorescence microplate reader.RESULTS:The retinal patch showed that NOX4 interference significantly reduced the destruction of the tight junctions between the retinal endothelium of RD rats and reduced leakage.Western blotting showed decreased expression of the NOX4 protein and decreased expression of ROS in retinal tissue;the Morris water maze test results showed that NOX4 interference significantly decreased the escape latency of the rats.CONCLUSION:NOX4 interference reduces the production of ROS in retinal vascular endothelial cells after experimental RD,thereby protecting the blood-retinal barrier and protecting visual function.     

Central serous chorioretinopathy shows reduced retinal flow circulation in retinal function imaging (RFI)

Purpose: To assess retinal blood flow in patients with central serous chorioretinopathy (CSR). Methods: The hospital‐based observational comparative study included a study group with 12 patients (age: 45 ± 13 years) with an acute onset of CSR and a control group of 12 subjects matched for age and gender with the study group. The diagnosis was substantiated by fluorescein angiography and optical coherence tomography. All study participants underwent measurement of retinal blood perfusion using the retinal function imager (RFI). Results: The retinal blood flow velocity in the retinal veins was significantly lower in the study group than in the control group (2.76 ± 0.53 mm/s versus 3.33 ± 0.76 mm/s; p = 0.03).The difference between the study group and control group was more marked for the larger retinal veins (2.87 ± 0.51 mm/s versus 3.47 ± 0.48 mm/s; p = 0.001) than for the smaller veins (2.69 ± 0.53 mm/s versus 3.42 ± 1.05 mm/s; p = 0.04). Both groups did not differ significantly in the data of the retinal arterial flow velocities. Conclusions: The data suggest an abnormal retinal venous blood flow regulation in patients with active CSR.     

The effect of pars plan vitrectomy on oxygen saturation in retinal vessels – a pilot study

Purpose: To determine the effect of pars plana vitrectomy (PPV) on oxygen saturation in retinal vessels. Methods: We performed a prospective consecutive interventional case series of 20 eyes of 20 patients with macular hole or epiretinal membrane. We performed automatic retinal oximetry (Oxymap Inc., Reykjavik, Iceland) in each patient 24 hr prior to and 45 days (range 42–49) after PPV (classic 20G or sutureless 23G). We analysed oxygen saturations in retinal arteries and veins. Vessel segments of first or second degree were selected. The same segment was analysed before and after PPV. Oximetry data were compared by paired two‐tailed t‐test. Results: Pars plana vitrectomy did not alter arterial haemoglobin saturation with oxygen (98 ± 2% prior to the surgery and 98 ± 3% after the procedure, p = 0.549). The mean venous haemoglobin saturation with oxygen increased after vitrectomy from 63 ± 10% to 66 ± 8% (p = 0.012). Conclusions: Oxygen saturation is higher in retinal veins after pars plana vitrectomy. Further studies are needed to unveil the mechanism of how vitrectomy affects oxygen metabolism in the retina.     

Macular microcirculation in hypertensive patients with and without branch retinal vein occlusion

Purpose: Our purpose was to determine whether a reduction in blood flow velocity (BFV) in the perifoveal capillaries is involved in the pathogenesis of branch retinal vein occlusion (BRVO) in patients with hypertension. Methods: Subjects included hypertensive patients with (n = 12) and without (n = 16) BRVO and healthy volunteers (n = 16). Perifoveal BFV was measured by the tracing method using fluorescein angiography and a scanning laser ophthalmoscope. Logistic regression analysis was performed to assess factors that influenced the presence or absence of BRVO. Results: Mean BFV showed a significant decrease across the three groups (healthy controls: 1.49 ± 0.11 mm/second; hypertensive patients without BRVO: 1.36 ± 0.12 mm/second; hypertensive patients with BRVO: 1.16 ± 0.24 mm/second; p_trend < 0.001). Multivariate logistic regression analysis showed that BFV was a significant risk factor for the presence of BRVO. Conclusions: Perifoveal capillary BFV is reduced in hypertensive patients with and without BRVO. It is possible that a decrease in BFV may be involved in the occurrence of BRVO. Measurement of perifoveal capillary BFV may be useful for investigating the pathogenesis and progression of BRVO.     

Calculation of central retinal artery diameters from non‐invasive ocular haemodynamic measurements in type 1 diabetes patients

Purpose: The aim of the study was to compare the diameter of the central retinal artery (CRA) between patients with diabetes mellitus and healthy subjects in vivo. CRA diameters were calculated from retinal haemodynamic parameters measured with noninvasive measurement techniques. Methods: Sixteen patients with type 1 diabetes with no or mild diabetic retinopathy and 16 age‐matched healthy controls were included in this study. Total retinal blood flow was assessed by combining bidirectional laser Doppler velocimetry in all veins entering the optic disc with measurements of retinal vessel diameters using a Dynamic Vessel Analyser. Blood flow velocity in the CRA was measured with colour Doppler imaging (CDI). The diameter of the CRA in the optic nerve was then calculated for each subject using the individual ocular haemodynamic data. Results: Calculated CRA diameters were significantly larger in patients with diabetes (180 ± 13 μm) compared with healthy controls (166 ± 10 μm, p = 0.001). No significant differences were found in retinal blood flow, retinal artery or vein diameters or mean flow velocity of the CRA. Conclusion: The data of the present study show increased calculated CRA diameter in patients with type 1 diabetes with no or mild retinopathy. Blood flow velocity measurements in retrobulbar vessels using CDI need to be interpreted with caution in terms of retinal blood flow, because no information about vessel diameters is obtained by this technique.     

近视眼视网膜的血氧代谢研究

目前近视眼视网膜血氧代谢研究主要聚焦于视网膜血氧饱和度和视网膜血流量。视网膜血氧饱和度研究现只局限于视网膜大血管的测量。近视眼患者视网膜血管直径减小,视网膜血流量下降,黄斑中心凹及视乳头周围毛细血管密度减少,中心凹无血管区范围增大。儿童青少年近视者视网膜动脉、静脉血氧饱和度与眼轴呈正相关。成年人高度近视眼动脉与静脉的血氧饱和度差值明显低于正视眼。     

0．2％阿法根滴眼液对视网膜血流影响的研究

目的 研究0．2％阿法根（Brimonidine）滴眼液对视网膜血流的影响。方法 选取开角型青光眼或高眼压症患者15例,采用自身对照方法,于0．2％阿法根滴眼液治疗前和治疗后2h分别行海德堡视网膜血流计（HRF）检查,观察视网膜中央动脉颞上、颞下、鼻上、鼻下4条分支血管血容量、血流及血流速度的变化。结果 0．2％阿法根滴眼液治疗前后视网膜中央动脉颞止、颞下、鼻上、鼻下4条分支血管的血容量、血流及血流速度无明显改变。结论 0．2％阿法根滴眼液局部使用对视网膜血流无影响。