前房灌注加压制作大鼠视网膜急性损伤模型

目的:成功制作大鼠视网膜急性损伤模型。方法:前房灌注加压至110 mm Hg,维持60 min。结果:12只大鼠均成功做成视网膜急性损伤模型,形态学观察也证实模型成功。结论:以针体开侧孔的针头,在手术显微镜下操作,成功地制作了大鼠视网膜急性损伤模型,且避免并发症发生。

电针不同穴位对单眼视神经离断家兔FVEP的影响

目的探讨针灸影响视觉系统的效应及其机理,明确视神经中之离中纤维在针刺影响视觉功能过程中的作用。方法24只白兔随机分为“合谷”组与“太溪”组,每组12只,制作单眼视神经离断家兔模型,切断视网膜与中枢的联系,但不损伤视网膜血循环,观察电针对双眼闪光视觉诱发电位(FVEP)的影响。结果在切断视神经时下行调制视网膜的离中纤维也被切断,术眼FVEP熄灭。电针“合谷”与“太溪”穴各时期对FVEP之N1、P1、N2各波峰潜时、振幅均有较强的抑制作用,表现为峰潜时延长,振幅明显降低,且这种抑制作用具有穴位的差异性。结论离中纤维在电针影响家兔闪光视网膜电图(FERG)及FVEP的过程中起到一定的作用,但针刺对FERG影响的主要途径不是通过中枢的下行性抑制,而是通过影响离中纤维在有限程度上对视网膜产生的影响。

大鼠视网膜缺血再灌注损伤中的细胞凋亡

目的 :观察大鼠视网膜缺血再灌注损伤 (retinalischemiareperfusioninjury ,RIR)中视网膜细胞的凋亡情况。方法 :利用前房高眼压灌注法 ,造成大鼠视网膜缺血 6 0分钟 ,然后恢复其供血 ,并分别于再灌注 12、2 4、4 8小时、7天后处死大鼠 ,摘取眼球作视网膜组织石蜡切片 ,用核苷酸末端转移酶介导的dUTP末端标记法 (terminaldeoxynucleotidyltransferasemediateddUTPnickend labeling ,TUNEL) ,亲和素 -生物素 -过氧化物酶技术 (avidinbiotinperoxidasecomplextechnique ,ABC)分别检测视网膜细胞的凋亡情况和P53 蛋白的表达和分布状况 ,同时对视网膜凋亡细胞进行计数并作统计学分析。结果 :RIR 12、2 4、4 8小时、7天后视网膜凋亡细胞数 (每高倍视野均数 )分别为 9 2± 0 912、2 5 6± 1 6 2 5、12 1± 1 6 0 9、0 0 2± 0 14 1。RIR 2 4小时时 ,P53 蛋白表达阳性。凋亡细胞及P53 阳性蛋白均出现在内核层 (innernuclearlayer ,INL)及神经节细胞层 (ganglioncelllayer ,GCL) ,而外核层 (outernuclearlayer,ONL)几乎无阳性表达。结论 :RIR中视网膜内层细胞存在着明显的凋亡征象。尤以RIR 2 4小时组最为显著。

微脉冲半导体激光照射对正常大鼠视网膜损伤的观察

目的观察810nm微脉冲半导体激光照射对正常棕色挪威大鼠（BN大鼠）视网膜的损伤。方法使用不同能量及负载系数（duty cycle，DC）的810nm微脉冲半导体激光对130只BN大鼠眼进行照射。分别于激光照射后第1、3、7、14、28d进行彩色眼底照相、荧光素眼底血管造影及组织病理学观察，并检测热休克蛋白（HSP-70）在视网膜的表达情况，用TdT介导dUTP缺口末端标记法（TUNEL）检查细胞凋亡。结果阈值及阈上能量条件下，低DC时激光照射部位无光学显微镜下的组织病理学改变，高DC时出现可累及视网膜内核层组织的严重损伤；微脉冲半导体激光照射后1d大鼠视网膜内核层细胞HSP-70阳性表达细胞即较正常视网膜明显增加，3d时达到高峰，以后逐渐下降，14d时恢复近正常水平。HSP-70阳性细胞数量随激光能量提高而增加。TUNEL染色可见激光照射部位凋亡细胞主要存在于视网膜色素上皮（RPE）层、外核层、内核层，甚至脉络膜层，其数量随激光能量增高而增多。在激光照射后第3d，凋亡细胞数量最多。结论810nm微脉冲半导体激光照射后，视网膜损伤程度与激光能量及DC呈正相关。低能量高负载系数（50mw，50％）或高能量低负载系数（100mw，5％～15％）时，损伤限于RPE层，避免了神经上皮层的损伤。激光照射后HSP-70高表达及细胞凋亡可能在组织损伤修复过程发挥重要作用。

N-甲基-D-天门冬氨酸受体亚型NR1、NR2A在大鼠视网膜缺血再灌注损伤模型中的表达

目的:研究N-甲基-D-天门冬氨酸受体(N-methyl-D-aspartate receptor,NMDAR)功能亚单位NMDAR1、NM-DAR2A在Wister大鼠视网膜缺血再灌注模型中的表达情况。方法:18只健康成年Wister大鼠分成6组,每组3只,都取其右眼行视神经周围血管结扎手术制备视网膜缺血再灌注模型,左眼作为对照组不行手术。60分钟后去除结扎缝线恢复血流,分别于再灌注后即刻、3、12、24、72、168小时处死大鼠,摘除眼球,做冰冻切片。用免疫组织化学方法观察NR1、NR2A在视网膜缺血再灌注后不同时刻的变化并进行图象分析及统计学处理。结果:(1)各实验组和对照组间及各实验组间NMDAR1的表达无统计学意义。(2)除即刻组外各实验组和对照组间及各实验组间NMDAR2A的表达均有统计学意义,从再灌注后3小时至168小时NMDR2A表达缓慢上升。结论:(1)NMDAR1与视网膜缺血再灌注损伤无关,不参与谷氨酸的兴奋性毒性作用。(2)NMDAR2A与视网膜缺血再灌注损伤有关,参与谷氨酸兴奋性毒性作用。

视网膜光损伤及其药物防护研究——组织化学定量分析

用荧光灯照射大鼠视网膜,应用组织化学微机图像处理方法,定量分析光损伤后视网膜细胞色素氧化酶和乙酰胆碱酯酶的动态改变,观察维生素E和β胡萝卜素对细胞色素氧化酶的防护效果,通过超微结构观察进行比较。结果:光照后细胞色素氧化酶活性下降,并与光照时间有关,提示光损伤可使此酶活性在一定范围内降低或恢复。就恢复时间而言,此酶活性改变与超微结构改变相符。乙酰胆碱脂酶仅呈一过性改变,部位也与超微结构改变吻合。与超微结构的改变相比,组化改变早而敏感。维生素E和β胡萝卜素对细胞色素氧化酶有较好的保护作用。

光损伤性视网膜病变4例报告

4例光损伤性视网膜病变眼底荧光血管造影,检查结果表明:损伤的黄斑区具有毛细血管拱环消失,色素上皮低荧光区扩大和环状荧光素渗漏等特点。临床观察结果显示:经用血管扩张剂、维生素E、C和皮质类固醇治疗后,视力均基本恢复正常。

ROLE OF CASPASE-3 IN ACUTE LIGHT DAMAGE TO RETINA OF RATS

Objective To investigate the role of Caspase-3 in retinal damage caused by hght exposure in rats. Methods Light injury to retina was induced by persistent exposure to illumination （intensity ： 30 000 ± 50 lux） of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1,3,7, and 15 days after the hght exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis. Results The examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, especially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pigment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day （82.7%） and 15th day （80.4%）, however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9. 8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day. Conclusion Apoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.

Action of induced hypertension and apoptosis: an experimental study in rat

Objective To study the retinal tissue degeneration of intraocular hypertension experimentally induced in acute and chronic way. Methods In the acute model, pressure elevation was quickly induced by a needle in the anterior chamber and the retinal reaction was studied at 1,2,4,5,7,10 days after treatment. The tissue damage with chronic hypertension,induced by the cauterization of two episcleral veins,was studied at 1 and 2 month after the treatment. The TUNEL method and Caspade 3a immunochemical study evidenced the apoptosis mechanism. The NADPH-diaphorase reaction identified the Nitric Oxide, ( NO) producing cells. Results In the acute model,the immunohistochemical study evidenced that the apoptosis was an early death mechanism for ganglionar cells. The activity of Nitric Oxide Synthase ( NOS) didn' t show a significant activation toward the retinal tissue of control. The chronic hypertension model indicated an increase in the NOS signal, meaning an activation of this enzyme in particular bear the vascular vessels, showing the neuroprotective and not only cytotoxic effect of the NO. The TUNEL and Caspase 3a studies indicated that the apoptosic mechanism started in different times, the immunohistochemical reaction showed its immediately beginning or its later activation caused by the chronic damage. Conclusions The opportunity to have a clear vision of the beginning and causing factors of cell degeneration in hypertension damage could permit the study on different substances that act on apoptosis , on NOS mechanism and on synaptic transmission inhibiting or deviating the retinal tissue degeneration and particularly the ganglionar cells death in glaucoma.

进一步加强视网膜血管异常与全身血管疾病的相关性研究

视网膜动脉缩窄、动静脉交叉压迫、微动脉瘤、视网膜出血、棉绒斑等视网膜血管异常表现与高血压等心血管疾病、糖尿病、脑卒中、肾病等全身血管疾病密切相关。充分利用现代眼底影像检查手段无创快捷、量化标准、智能分析等技术优势，全面采集视网膜血管异常信息，深入探讨视网膜血管异常的形成转归机制以及与全身血管疾病之间的关系，不仅有助于进一步提升视网膜血管异常疾病的诊断治疗水平，而且还将有助于预测全身血管疾病的发生风险和干预效果。充分利用新的眼底影像检查技术，进一步加强视网膜血管异常与全身血管疾病的相关性研究，通过诊断视网膜血管疾病，为全身血管疾病的预防治疗提供证据；同时通过治疗全身血管疾病，为更好地治疗视网膜血管疾病提供基础。二者相辅相成，整体与局部互为促进，为患者带来更好的预后是未来医学发展的方向。

鱼雷样黄斑病变的研究现状与进展

鱼雷样黄斑病变(TM)是一种罕见的、先天性RPE损害,位于黄斑颞侧,沿水平缝走行,尖端指向中心凹,呈特征性的鱼雷样改变。该病以单眼发病为多见,不影响中心视力。根据其在OCT上的特点分为两型。Ⅰ型表现为轻微的外层视网膜紊乱不伴有外层视网膜腔隙;Ⅱ型为外层视网膜结构紊乱伴外层视网膜腔隙。与TM类似的RPE层色素改变的疾病包括先天性RPE肥大、Gardner综合征的RPE损害等,鉴别该病与其他疾病的要点是其独特的位置与形态。TM多数稳定,不需要特殊治疗;但由于其可合并神经上皮层脱离、脉络膜新生血管等,必要时需要对症治疗。

Retinochoroidal changes after severe brain impact injury in rabbits

Objective:: To investigate retinochoroidal changes and establish eye damage model after brain impact injury. Methods: An eye damage model after brain impact injury was established by striking the frontoparietal zone in rabbits with BIM-Ⅱ bioimpact machine. Seventeen rabbits were killed at 4 different intervals after injury. The pathological characteristics of the retinal and choroid damages were observed. Results: All the rabbits had severe brain injury with subarachnoid hemorrhage and brain contusion. The eye damage occurred in all of the 17 rabbits. Hemorrhage in optic nerve sheaths was observed and retinal edema and bleeding was discovered with ophthalmoscope. Histopathologic study displayed subarachnoid hemorrhage in the retrobulbar portion of the retinal nerve, general choroid blood vessel dilatation, retinal nerve fibre swelling within 6 hours after injury, and flat retinal detachment with subretinal proteinoid exudation, and degeneration and disappearance of the outer segment of the optic cell over 6 hours after injury. Conclusions: The pathological characteristic of the eye damage at early stage following brain impact injury is local circulation disturbance. At late stage, it features in retinal detachment, and optic cellular degeneration and necrosis.

Epac2-deficiency leads to more severe retinal swelling, glial reactivity and oxidative stress in transient middle cerebral artery occlusion induced ischemic retinopathy

Ischemia occurs in diabetic retinopathy with neuronal loss, edema, glial cell reactivity and oxidative stress. Epacs, consisting of Epac 1 and Epac2, are cAMP mediators playing important roles in maintenance of endothelial barrier and neuronal functions To investigate the roles of Epacs in the pathogenesis of ischemic retinopathy, transient middle cerebral artery occlusion （tMCAO） was performed on Epacl-deficient （Epacl-/- ） mice, Epac2-deficient （Epac2-/-） mice, and their wild type counter-parts （Epacl＋/＋ and Epac2＋/＋）. Two-hour occlusion and 22-hour reperfusion were conducted to induce ischemia/reperfusion injury to the retina. After tMCAO, the contralateral retinae displayed similar morphology between different genotypes. Neu-ronal loss, retinal edema and increase in immunoreactivity for aquaporin 4 （AQP4）, glial fibrillary acidic protein （GFAP）, peroxiredoxin 6 （Prx6） were observed in ipsilateral retinae. Epac2 / ipsilateral retinae showed more neuronal loss in retinal ganglion cell layer, increased retinal thickness and stronger immunostaining of AQP4, GFAP, and Prx6 than those of Epac2＋/＋. However, Epacl-/- ipsilateral retinae displayed similar pathology as those in Epacl＋/＋ mice. Our observations suggest that Epac2-deficiency led to more severe ischemic retinopathy after retinal ischemia/reperfusion injury.