眼内铜异物视网膜脂质过氧化损伤的实验研究

铜丝置入兔眼玻璃体内,原子吸收分光光度法检测房水和玻璃体内微量元素铜,发现随着房水和玻璃体铜离子浓度的升高,视网膜脂质过氧化反应增强,并伴有视网膜电流图和超微结构的异常。实验结果表明,铜离子诱发的脂质过氧化反应是视网膜损伤的重要因素。     

大鼠角膜碱烧伤后视网膜丙二醛含量及超氧化物歧化酶活性的变化

目的研究严重眼前段碱烧伤后视网膜组织中丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性的改变。方法Wistar大鼠双眼角膜用1mol／L NaOH溶液烧伤30秒，分别于烧伤后1、3、7、15和30天处死动物，摘除眼球，制作视网膜组织匀浆，检测MDA含量和SOD活性。以正常大鼠作对照。结果碱烧伤后视网膜组织中MDA含量逐渐升高，7天达顶峰，以后逐渐下降，30天时接近正常；SOD活性在碱烧伤后即开始下降，7天时最低，以后逐渐升高，30天时接近正常。结论严重眼前段碱烧伤后视网膜组织中可能存在脂质过氧化反应，其结果将加重视网膜组织的损伤。     

牛磺酸对离体视网膜组织脂质过氧化反应保护机制的实验研究

目的：探时牛磺酸对离体家免视网膜组织脂质过氧化反应、超氧化物歧化酶(superoxide dismutase,SOD)及谷胱过氧化物酶(glutathione，peroxidase,GSH-Px)活性的影响。 方法：将家兔眼球视杯置于4组(对照组、模型组、牛磷酸组、β—胡萝卜素组)培养液中，5%CO₂，37°C温育．分别于24小时和48小时时后测定视网膜组织中SOD，GSH-Px、蛋白及丙二醛(malondialdehyde，MDA)．结果：牛磺酸与β-胡萝卜索一样可以抑制视网膜组织内脂质过氧化反应，减少MDA生成；对SOD保护作用不确定，对GSH-Px无保护作用。 结论；牛磺酸可抑制视网膜组织脂质过氧化反应，其机制可能与对SOD,GSH—Px活性的膨响无关。 （中华眼底病杂志，1996，12：183-185）     

二硫化碳毒性视网膜功能损害与脂质过氧化反应关系的实验研究

为探讨二硫化碳毒性视网膜功能损害与脂质过氧化反应的关系，进行兔眼ERG生化检测。结果染毒3周后，染毒兔ERGb波振幅明显低于对照组，视网膜超氧化物歧化酶总活力（TSOD）较对照组降低，而MDA活性增高。ERGb波振幅与TSOD呈正相关而与MDA呈负相关。结论CS2毒性视网膜功能损害可能与脂质过氧化反应有关。     

兔晶体机械性创伤后超氧化物歧化酶活性和丙二醛含量的动态测定

对兔晶体机械性创伤后不同时间的SOD活性和MDA含量测定表明:创伤后第21天内.实验组和对照组比较,SOD活性显著性下降(P<0.01)、MDA含量显著性升高(P<0.01),提示:晶体创伤后自由基代谢异常和脂质过氧化作用增强,是眼外伤并发症的重要病理过程.     

视网膜脱离PVR形成与脂质过氧化关系的实验研究

目的 探讨视网膜脱离（ＲＤ）后增生性玻璃体视网膜病变（ＰＶＲ）形成与脂质过氧化反应的关系。方法 建立成年健康家兔ＲＤ模型９只眼，临床观察ＰＶＲ形成情况，同时视网膜脱离前后脱离后５，１５，３０天分别抽取血及玻璃体标本，测量超氧化物歧化酶总活力（ＴＳＯＤ）铜锌超氧化物歧化酶（ＣｕＺｎＳＯＤ）锰超氧化物歧化酶（ＭｎＳＯＤ）及脂质过氧化物（ＬＰＯ）含量。结果 （１）视网膜脱离５天后，血清及玻璃体ＬＰＯ活性     

阿魏酸钠对大鼠慢性高眼压模型视网膜MDA和SOD的影响

目的:探讨阿魏酸钠(ferulic acid sodium)对大鼠慢性高眼压模型视网膜氧化损伤的抑制作用。方法:SD大鼠40只随机分为空白对照组、生理盐水组和阿魏酸钠5和10mg/kg组并做慢性高眼压模型,每日测量眼压,并于术后1,3,7,14,28d检测视网膜组织中丙二醛(maleic dialdehyde,MDA)含量和超氧化物歧化酶(superoxide dismutase,SOD)活性。结果:术后MDA和SOD均显著升高,观察期内空白对照组和生理盐水组MDA含量无显著变化,阿魏酸钠组于术后7d开始下降,28d时接近正常水平。空白对照组和生理盐水组SOD活性短暂升高后快速下降,阿魏酸钠组下降明显延续,观察期内维持于较高水平。结论:阿魏酸钠通过清除氧自由基或保护SOD活性对持续性高眼压视网膜氧化应激具有保护作用。     

高功率微波对视网膜神经节细胞脂质过氧化作用的实验研究

目的 观察微波对体外培养的兔视网膜神经节细胞的脂质过氧化损伤作用。 方法 体外培养兔神经节细胞,以平均功率为80　mW/cm²的微波进行辐照,辐照时间分别为15、30、45min。辐照后立即于倒置显微镜和电镜下观察细胞形态变化,羟胺法和改良硫代巴比妥酸荧光法分别测定细胞内超氧化物歧化酶(superoxide dismutase,SOD)和丙二醛(malondialdehyde,MDA)含量。 结果 微波辐照后,细胞轴突消失,电镜可见线粒体及内质网肿胀。随辐照时间延长,细胞逐渐趋向于坏死,细胞MDA含量增高,45min辐照组MDA含量为对照组的5.11倍。SOD则逐渐降低。 结论 微波可引起视网膜神经节细胞脂质过氧化损伤,脂质过氧化反应可能是微波视网膜损伤的作用机制之一。 (中华眼底病杂志,2000,16：32-34)     

NLRP3/IL-1β通路在增殖性糖尿病视网膜病变中的作用机制

目的：探究核苷酸结合寡聚化结构域样受体3(NLRP3)/白介素-1β(IL-1β)通路在增殖性糖尿病视网膜病变中的作用机制。

方法：收集2015-09/2018-03我院眼科收治的增殖性糖尿病视网膜病变患者49例49眼(研究组)和特发性黄斑裂孔患者41例41眼(对照组)。检测研究组患者视网膜增殖前膜与对照组患者黄斑前膜中NLRP3蛋白表达情况、活性氧簇(ROS)、丙二醛(MDA)水平与超氧化物歧化酶(SOD)活性,测定两组患者玻璃体中IL-1β与IL-18浓度。

结果：研究组患者视网膜增殖前膜中NLRP3蛋白阳性表达率明显高于对照组患者黄斑前膜(90% vs 5%,P<0.05),且研究组患者视网膜增殖前膜中ROS与MDA水平明显升高,而SOD活性明显降低。研究组患者玻璃体中IL-1β、IL-18浓度(30.84±7.15、97.61±15.73pg/mL)均明显高于对照组(4.63±0.92、52.07±11.38pg/mL)。

结论：NLRP3与IL-1β在增殖性糖尿病视网膜病变组织中呈高表达,NLRP3/IL-1β通路可上调炎性因子与氧化因子表达水平,促进疾病发展。     

炸药燃烧残留物对兔视网膜的毒性研究

目的 探讨兔眼玻璃体腔内黑色火药燃烧残留物对视网膜的毒性.方法 制作兔眼内黑色火药燃烧残留物模型.术后1、3、7、14d抽取0.1 mL玻璃体行硫化物测定;剥取视网膜测定其超氧化物歧化酶(SOD)和丙二醛(MDA)含量;摘除眼球进行常规HE及透射电镜观察.结果 实验组视网膜SOD、MDA含量较对照组明显升高;玻璃体内硫化物含量先升高后下降;光镜下见视网膜变薄、各层细胞减少、核固缩;电镜下线粒体肿胀、粗面内质网脱颗粒、细胞排列紊乱稀疏、正常细胞结构改变等.结论 兔眼玻璃体腔内黑色火药燃烧残留物对视网膜有毒性作用.其机制可能是早期引起细胞凋亡,后期硫化物影响细胞的氧化.     

孔源性视网膜脱离视网膜下液丙二醛和锌,铜含量测定及临床意义

对８０例孔源性视网膜脱离患者视网膜下液及血清丙二醛、锌和铜水平进行了测定。结果表明：ＳＲＦ中有脂质过氧化毒性产物，其含量随ＲＲＤ眼瓿病变程度的加重而增加，并与ＳＲＦ中锌含量呈正相关。中度以上近视患者血清Ｃｕ／Ｚｎ比值显著高于正常人和低度近视患者（Ｐ≤０．０５）。锌、铜代谢异常和脂质过氧化毒性作用可能是ＲＲＤ发生和发展的病理因素之一。     

Pathogenesis of disorders of transparency of the optic media of the eye. III. Quantitative detection of copper in relation to the ultrastructure of the vitreous body in chalcosis

The authors elaborated a new analytical micromethod for the detection of elements in morphologically investigated ultrastructures of the vitreous body. For the investigation of quantitative ultrastructural changes electron microanalysis (EMA) was used, combined with raster electron microscopy (REM). Using this method, the authors proved ultrastructural changes of the vitreous body by selective uptake of copper in the trabecular collagen fibres of the vitreous body in experimental chalcosis. From the results ensues that copper does not diffuse in the vitreous body in a homogeneous manner but aggregates in irregular agglomerations of precipitates and crystals. The different quantitative detection of copper in different parts of the same specimen is according to the authors due to the heterogeneous affinity of ultrastructural portions of the vitreous body for copper.     

外伤性白内障眼内SOD与LPO研究

采用ＴＢＡ比色法测定１５只家兔外伤性白内障眼组织脂质过氧化（ＬＰＯ）产物丙二醛（ＭＤＡ）含量变化；用发光法测定了超氧化物歧化酶（ＳＯＤ）的含量变化。外伤眼的晶体、房水、玻璃体中ＭＤＡ的含量分别较正常对照高４．４倍，１．７６倍和１．６４倍。外伤眼晶体内ＳＯＤ活力较正常对照降低６．９２倍；外伤性白内障晶体中ＬＰＯ明显增强，抗氧化能力明显下降，而房水、玻璃体中ＬＰＯ和抗氧化程度均增强。证实自由基代谢紊乱     

视网膜下液脂质过氧化物含量及临床意义

用八木国夫TBA荧光法测定42例孔源性视网膜脱离病人视网膜下液和血清中脂质过氧化物含量。结果表明:视网膜下液中存在脂质过氧化代谢产物,其含量与增殖性玻璃体视网膜病变呈正线性相关(r=0.78),与病程呈非线性正相关(r=0.45)。视网膜的退行性变,继发性的抗过氧化能减低,可能导致脂质过氧化毒性作用占优势,促使脱离的视网膜发生一系例的病理改变。     

Chalcosis bulbi recognized 22 years after trauma

PURPOSE: To report a case of chalcosis bulbi diagnosed 22 years after accidental entry of a foreign object into the eye. CASE: A 57 year-old woman underwent surgery for vitreous opacity and cataract of unknown cause. During the operation, an intraocular foreign body was found in the vitreous at the pars plana, and was removed. The object was a coated copper wire, 3.5 mm in length and 0.2 mm in thickness. She recalled that such a wire had accidentally entered her eye 22 years previously. Copper particles were detected by copper staining of the anterior lens capsule. RESULT: Fine, sharp metal fragments may penetrate the eye with little resistance. When the injury results in minimal subjective symptoms, the person may not seek examination by an ophthalmologist. In the present case, the foreign body was a fragment of coated copper wire. The exposed metal surface was limited and the copper probably dissolved very slowly. This may account for the lack of significant symptoms. In the Japanese literature, there are many reports of coated copper wire as foreign body in the eye, but few lead to characteristic chalcosis bulbi.     

Pathogenesis of transparency disorders of the optical environment of the eye. IV. Electron microscopy study of the vitreous body in chalcosis

The authors proved, based on electron microscopic analysis that the vitreous body of the rabbit creates under physiological conditions a regular network of collagenous fibrils with a different cell population. The cells can be divided into three basic types: 1. Large cells with a lobular nucleus and well differentiated cytoplasm and multiple organelles which ensure a high metabolic activity. 2. The second type are cells of an elongated shape with an oval nucleus surrounded by a thin layer of cytoplasm with a small amount of organelles. 3. The third type are large globular cells with a homogeneous structureless mass. The basic cytoplasm with the nucleus and a negligible amount of organelles is pushed to the cell surface and thus forms a thin layer beneath the plasmalemma. Contrary to the pathologically altered vitreous body, the authors did not detect on the sound vitreous body any phagocytosing cells. On the other hand, the long-term effect of copper in experimental chalcosis markedly alters the cytological character of the structure of the vitreous body. Cell types typical for a sound vitreous body were not found in the affected eye in chalcosis. In addition to rare destroyed cells containing autophagosomes of varying size with incomplete plasmalemma at some sites there is the important finding of two different forms of phagocytes in the pathological vitreous body: 1. Neutrophil granulocytes and 2. Macrophages containing large phagosomes in the cytoplasm. Their function is to eliminate destroyed tissues and engulfing of copper particles.     

A possible mechanism for transpupillary thermotherapy: nitric-oxide-related cellular damage

BACKGROUND: To determine the oxidative stress markers on rabbit vitreous following transpupillary thermotherapy (TTT) application. METHODS: The pigmented rabbit eyes were divided into 3 groups, each containing 6 eyes. Group 1 was used as a control group. Twelve eyes underwent TTT with a power of 250 mW (group 2) and 800 mW (group 3), with a diameter of 3000 microm and duration of 60 s; 24 h after laser application, vitreous samples were collected. Nitric oxide (NO) and malondialdehyde (MDA) levels and superoxide dismutase (SOD) activities were determined in all groups. RESULTS: NO levels were statistically significantly higher in all groups when compared with the control group (p < 0.05). MDA levels were higher and SOD activities were lower in all groups when compared with the control group, but the differences were not significant statistically (p > 0.05). INTERPRETATION: Our results support the hypothesis that TTT application induces NO synthesis, which may lead to occlusion at choroidal neovessels. Because of the nonsignificantly increased levels of MDA and decrease of SOD activities there maybe only a weak relation between lipid peroxidation induced by free oxygen radicals and TTT-induced vascular damage.     

The pathophysiology of the ocular microenvironment. II. Copper-induced ocular inflammation and hypotony

The ocular effects of intravitreally injected copper sulfate solutions were studied in New Zealand white rabbits. These injections resulted in uveitis characterized by prolonged ocular hypotony, increased protein concentrations and decreased ascorbic acid concentrations in both the vitreous and aqueous humors, and an apparent decrease in the transport function of the anterior uvea. The extent and the duration of these effects were dose-dependent. The lower doses used, 3 or 6 micrograms of Cu as CuSO4 per eye, produced reversible inflammation. The highest dose, 30 micrograms of Cu per eye, also produced some signs of ocular chalcosis: hemorrhage, vitreous liquefaction, prolonged hypotony and local iridial ischemia. Six hours after the intravitreal injection of 6 micrograms of Cu as CuSO4 per eye, the Cu concentration in the vitreous humor increased to approximately 100 times that in the vitreous of control eyes, and began to decline only 3 days later, with a half-time of approximately 8 days. The Cu concentration in the anterior chamber of these eyes never exceeded 1 ppm and returned close to control values within 3 days. Based on these findings, factors that affect ocular trace-metal distribution and kinetics are discussed, as are reasons for the apparent difficulty in diagnosing the presence of Cu-containing intraocular foreign bodies on the basis of the Cu concentration of the aqueous humor.     

Ontogeny of VEGF, IGF-I, and GH in neonatal rat serum, vitreous fluid, and retina from birth to weaning

PURPOSE: Vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF)-I, and growth hormone (GH) are major regulators of physical growth, as well as normal and pathologic retinal development. Ocular tissues are protected by the blood-ocular barrier. This study was conducted to test the hypothesis that the ontogenic profiles of VEGF, IGF-I, and GH in the rat serum, vitreous fluid, and retina are compartment specific, and that the vitreous is a reservoir for retinal growth factors. METHODS: Sprague-Dawley rat pups were killed at birth (postnatal day [P]0) and at P7, P14, and P21. At death, serum, vitreous fluid, and retinal homogenates were analyzed for ontogeny of VEGF, IGF-I, and GH. RESULTS: VEGF levels were 10 times higher in the vitreous than in serum at all stages of development. Vitreous and serum VEGF levels progressively declined, with lowest concentrations at P21. Retinal VEGF levels increased with the highest concentration at P21. IGF-I levels in the vitreous decreased from P7 through P21. IGF-I levels in serum and retinal homogenates increased with advancing postnatal age. Although IGF-I levels were four times higher in the vitreous than in the retina at P0, equilibration was achieved at P21. GH levels in the vitreous were 10 times lower than serum levels, were decreased at P14 and P21, and remained unchanged from P0 through P21 in the retina. CONCLUSIONS: VEGF and IGF-I act in concert to promote retinal development with the vitreous fluid as a reservoir. The ontogenic profiles of VEGF, IGF-I and GH in the serum and ocular compartments are specific. These differences should be considered when therapies for ROP are proposed.     

Intravitreal pharmacokinetics in rabbits of the foscarnet lipid prodrug: 1-O-octadecyl-sn-glycerol-3-phosphonoformate (ODG-PFA).

PURPOSE: To evaluate the intraocular distribution and metabolism of the lipid prodrug of foscarnet, 1-O-octadecyl-sn-glycerol-3- phosphonoformate (ODG-PFA), following intravitreal administration. METHODS: Twenty rabbits received ODG-[14C]PFA intravitreal injection, yielding 0.632 mM resultant intravitreal concentration. Two animals per group were sacrificed at different intervals post-injection. The drug levels in ocular tissues were determined with counting the radioactivity by Tracor Mark III Liquid Scintillation Counter. Four rabbits were used for analysis of the drug metabolism in vitreous by lipid extraction technique. RESULTS: The drug level in vitreous was 526 microM at day one and 227 microM at the fifth week. The vitreous half life was approximately four to five weeks. The retinal level of the drug was 292 microM at day one, 75 microM at the fifth week and 32 microM at the tenth week, which was still more than ten times higher than the IC90 against HCMV. Lipid extraction analysis showed that, in vivo, both ODG-PFA and PFA were present in vitreous, but in in vitro incubations with vitreous, ODG-PFA conversion to PFA was negligible. CONCLUSION: ODG-PFA possesses a long vitreous half life and sustained high drug level in retina. The vitreous did not metabolize drug but acted as a drug reservoir. Intravitreal liposomal ODG-PFA may be expected to be a long acting potent local therapy for CMV retinitis.