吲哚美辛对体外培养的RPE细胞增殖及DNA合成的影响

目的探讨吲哚美辛(IN)对体外培养的人胚胎视网膜色素上皮(RPE)细胞的抑制作用及DNA合成的影响。方法 分别用核酸蛋白分析仪测定加入50、100、200、400、600μmol/L IN作用24 h后RPE细胞DNA质量浓度的变化和MTT法测定加入100、200、400、600、800、1 000 μmol/L IN 12 h后RPE细胞数量的改变。 结果 前者其细胞DNA质量浓度(单位:μg/ml)分别为101.171 2±15.512 4、88.640 0±13.584 5、72.365 1±7.796 9、5.908 9±10.722 9、51.223 6±8.775 7。与对照组21 3.735 1±83.157 2相比,差异有显著性(q值分别为5.481、6.091、6.883、7.490、7.912,P值分别为0.000、0.000、0.000、0.000、0.000);后者其细胞A值分别为0.236 7±0.054 6、0.168 7±0.069 5、0.081 9±0.034 6、0.065 6±0.017 6、0.055 4±0.028 6、0.050 8±0.027 7。与对照组0.267 4 ±0.043 0相比,差异有显著性(q值分别为1.442、4.621、8.682、9.447、9.925、10.140,P值分别为0.158、0.000、0.000、0.000、0.000、0.000)。 结论 IN可抑制体外培养的RPE细胞的DNA合成及增殖。     

虾青素对晶状体上皮细胞氧化应激损伤的抑制作用及其机制北大核心CSCD

目的研究虾青素对过氧化氢(H_(2)O_(2))诱导晶状体上皮细胞HLEB-3氧化应激损伤的调控作用及其可能的作用机制。方法将HLEB-3细胞于不同浓度H_(2)O_(2)(0、50、100、200、500、750μmol/L)下培养,噻唑蓝(MTT)法检测细胞抑制率,计算半数抑制浓度(IC50)。将HLEB-3细胞使用不同浓度(0、5、10、20、50μmol/L)虾青素培养,MTT法检测细胞存活率。将HLEB-3细胞分为4个组,其中正常对照组用完全培养基培养、氧化应激组于250μmol/L H_(2)O_(2)培养基中培养,10μmol/L虾青素组和20μmol/L虾青素组分别于相应浓度虾青素+250μmol/L H_(2)O_(2)培养基中培养,各组均培养24 h。采用流式细胞仪检测细胞凋亡率;采用ELISA法检测细胞一氧化氮(NO)浓度、超氧化物歧化酶(SOD)活性、还原型谷胱甘肽(GSH)活性和丙二醛(MDA)含量;采用Western bolt法检测细胞核核因子E2相关因子2(Nrf2)、细胞质Nrf2和血红素加氧酶-1(HO-1)、醌氧化还原酶1(NQO1)蛋白表达。另将细胞分为正常对照-小干扰RNA(NC-siRNA)组、Nrf2-siRNA组、NC-siRNA+虾青素组和Nrf2-siRNA+虾青素组,分别转染NC-siRNA或Nrf2-siRNA,转染后24 h分别于含0或10μmol/L虾青素和250μmol/L H_(2)O_(2)培养基中培养24 h。采用流式细胞仪检测细胞凋亡率,采用ELISA法检测细胞NO浓度、SOD活性、GSH活性和MDA含量。结果随着H_(2)O_(2)浓度的增加,HLEB-3细胞抑制率升高,不同浓度H_(2)O_(2)处理细胞的抑制率总体比较差异有统计学意义(F=12.358,P<0.05)。H_(2)O_(2)对HLEB-3细胞的IC50为264.20μmol/L。0、5、10、20、50μmol/L虾青素处理HLEB-3细胞的存活率分别为(100.00±0.00)%,(102.20±1.34)%、(109.50±3.60)%、(115.40±4.13)%和(93.60±2.59)%,后续选取10μmol/L和20μmol/L作为实验剂量。氧化应激组细胞凋亡率为(38.50±2.38)%,高于正常对照组的(9.20±0.24)%,差异有统计学意义(P<0.05);10μmol/L虾青素组细胞凋亡率为(27.60±4.33)%,低于氧化应激组,高于20μmol/L虾青素组的(14.90±1.23)%和正常对照组,差异均有统计学意义(均P<0.05)。氧化应激组细胞中NO浓度、MDA含量高于正常对照组、10μmol/L虾青素组和20μmol/L虾青素组,SOD、GSH活性低于正常对照组、10μmol/L虾青素组和20μmol/L虾青素组,差异均有统计学意义(均P<0.05);10μmol/L虾青素组NO浓度、MDA含量高于20μmol/L虾青素组和正常对照组,SOD、GSH活性低于20μmol/L虾青素组和正常对照组,差异均有统计学意义(均P<0.05)。各组间细胞核Nrf2、细胞质Nrf2、HO-1和NQO1蛋白相对表达量总体比较,差异均有统计学意义(F=43.512、20.381、31.014、23.435,均P<0.001);正常对照组、氧化应激组、10μmol/L虾青素组和20μmol/L虾青素组细胞质Nrf2蛋白相对表达量逐渐下降,细胞核Nrf2、HO-1和NQO1蛋白相对表达量逐渐升高,组间两两比较,差异均有统计学意义(均P<0.05)。Nrf2-siRNA组和Nrf2-siRNA+虾青素组细胞凋亡率高于NC-siRNA组和NC-siRNA+虾青素组,NC-siRNA组细胞凋亡率高于NC-siRNA+虾青素组,差异均有统计学意义(均P<0.05);Nrf2-siRNA+虾青素组和Nrf2-siRNA组细胞凋亡率差异无统计学意义(P>0.05)。Nrf2-siRNA组细胞NO浓度、MDA含量高于NC-siRNA组,SOD、GSH活性低于NC-siRNA组,差异均有统计学意义(均P<0.05);NC-siRNA+虾青素组NO浓度、MDA含量低于NC-siRNA组和Nrf2-siRNA+虾青素组,SOD、GSH活性高于NC-siRNA组和Nrf2-siRNA+虾青素组,差异均有统计学意义(均P<0.05);Nrf2-siRNA+虾青素组细胞NO浓度、SOD和GSH活性及MDA含量与Nrf2-siRNA组比较,差异均无统计学意义(均P>0.05)。结论虾青素能提高晶状体上皮细胞抗H_(2)O_(2)诱导的氧化应激损伤能力,其作用可能是通过活化Nrf2相关信号通路而实现的。     

红景天对培养人视网膜色素上皮细胞增生和DNA合成的抑制作用

目的 研究红景天对体外培养视网膜色素上皮细胞增生的抑制作用及可能机制。方法 通过活细胞计数法与MTT比色法分别检测不同质量浓度(500、400、300、200、100、50、10μg／mL)红景天和红景天200μg／mL在不同作用时间(6～120h)对RPE细胞增生及代谢的影响。结果 红景天组细胞增生受抑制并出现细胞脱落，红景天400μg／mL具有最强的抑制效应，其明显抑制效应在6h即出现，72h达高峰。红景天组L4值日明显低于对照组，RPE细胞生存率下降。结论 红景天可能通过干扰RPE细胞代谢对RPE细胞增殖具有剂量依赖和时间依赖方式的抑制作用。     

槲皮素对培养人视网膜色素上皮细胞增生及DNA合成的影响

目的研究槲皮素(quercetin, QUE)对培养人视网膜色素上皮(retinal pigment epithelium, RPE)细胞增生和DNA合成以及对表皮生长因子(epidermal growth factor, EGF)促RPE细胞增生和DNA合成作用的影响。方法用细胞计数和3H-胸腺嘧啶核苷(3H-thymidine, 3H-TdR)掺入方法,观察不同浓度(200、100、50、1μmol/L)的QUE和最大浓度的QUE(200μmol/L)在不同作用时间（24-168小时）,分别单独或与EGF共同作用时,对RPE细胞增生及DNA合成的影响,排除着色的死细胞,用活细胞计数法判断药物的细胞毒性作用。结果QUE 200μmol/L具有最强的抑制效应,48小时时抑制效应已明显出现,96小时时抑制达到高峰。与QUE单独作用相比,QUE对EGF的促RPE细胞增生效应能产生更强的抑制。QUE无细胞毒性作用,各实验组细胞活力均在85.00%以上。结论QUE以剂量依赖和时间依赖的方式抑制RPE细胞的增生,尤其是由EGF刺激的增生,并且对培养的RPE细胞无细胞毒作用。(中华眼底病杂志,1999,15:27-29)     

槲皮素对H2O2诱导人RPE细胞氧化应激损伤的保护作用

目的：探讨槲皮素对H2 O2诱导的人视网膜色素上皮细胞( retina pigment epithelium,RPE)氧化应激损伤的保护作用及可能机制。
　　方法：RPE细胞传代培养,分为阴性对照组：以正常培养液培养;氧化损伤组：100μmol/L的H2 O2作用12h;槲皮素低浓度组：100μmol/L 槲皮素孵育24h 后,加入 H2 O2作用12 h;槲皮素高浓度组：500μmol/L槲皮素孵育24 h后,加入H2 O2作用12h。 MTT比色法检测细胞活力,流式细胞仪检测细胞凋亡率, Hochest33258染色观察凋亡细胞形态,比色法检测细胞中过氧化氢酶( catalase,CAT)、超氧化物歧化酶( superoxide dismutase,SOD)和谷胱甘肽过氧化物酶( glutathione peroxidase,GSH-Px)活性。
　　结果：槲皮素能明显抑制H2 O2诱导的RPE细胞活力的下降,用不同浓度槲皮素处理后,RPE细胞活性分别提高到79.67%±4.98%和83.00%±3.60%,与氧化损伤组(48.93%±3.39%)比较,差异具有统计学意义(P<0.05);经不同浓度槲皮素处理后, RPE细胞凋亡率分别下降至23.23%±3.29%和16.23%±1.94%,与氧化损伤组(38.03%±4.76%)比较,差异具有统计学意义(P<0.05);此外,槲皮素还能增加细胞中CAT、SOD、GSH-Px活性,与氧化损伤组比较,差异均具有统计学意义(P<0.05)。
　　结论：槲皮素通过改善细胞中抗氧化酶活性有效抑制了H2 O2对RPE细胞的损伤,从而为其用于治疗RPE细胞损伤提供可靠的实验±据。     

金黄色葡萄球菌培养上清液对中性粒细胞及RPE细胞炎性相关因子表达的影响

目的 观察金黄色葡萄球菌培养上清液对中性粒细胞及视网膜色素上皮细胞(RPE)炎性相关因子IL-1β、TNF-α、IL-6表达水平的变化.方法 实验研究.分离入外周血中性粒细胞,与人RPE细胞株D407共培养,加入无菌体的金黄色葡萄球菌ATCC29213培养上清液.其中细菌上清液分为50μl、100μl、250μl、500μl以及空白组、脑心浸萃液态培养基对照组6组;中性粒细胞数量分为空白组、1 ×104、5 ×104、5×105,4组.在6、12、24、48、72 h等时间点搜集培养液上清,应用酶联免疫吸附试验检测培养液中IL-1β、TNF-α、IL-6表达水平的变化.结果 当不同剂量金黄色葡萄球菌上清液单独作用RPE细胞时,培养液中IL-1β水平随着细菌上清液剂量增加而上升、亦随着作用时间的延长而增加;但IL-6水平500μl组高于空白组,仅在24h[(23.17±3.16)ng/L;(7.61±1.53) ng/L]及48 h[ (35.00 ±4.37) ng/L;(13.17±3.27)ng/L]时差异具有统计学意义(P =0.001;P =0.026).RPE细胞在100μl细菌上清液作用下,加入不同数量中性粒细胞共培养,5×105组培养液中IL-1β水平在6 h[ (236.62±8.20) ng/L]及12 h[ (447.42±35.13)ng/L]均高于其余各组,差异具有统计学意义(6 h:P =0.000,P=0.000,P=0.002;12 h:P =0.000,P=0.000,P=0.000);培养液中IL-6的水平在12 h时5×105组[( 46.96±2.72) ng/L]亦高于其余各组,差异具有统计学意义(P =0.000,P=0.000,P=0.000).在各时间点培养液中均检测不到明显的TNF-α表达.结论 中性粒细胞及RPE细胞共培养体系在金黄色葡萄球菌上清液的刺激下可检测到IL-1β和IL-6表达;其中IL-1β表达在早期出现,且高水平状态维持较长.金黄色葡萄球菌的毒力因子含量及中性粒细胞数量对引发IL-1β和IL-6的高表达起重要作用.     

三氧化二砷对表皮生长因子诱导的视网膜色素上皮细胞增生和迁移的影响

背景 细胞因子失衡所导致的视网膜色素上皮(RPE)细胞的异常增生和迁移是增生性玻璃体视网膜病变( PVR)的主要病理变化之一.三氧化二砷(As2O3)是中国传统中药中的有效成分,可有效抑制肿瘤细胞的增生和迁移.但As2O3对细胞生长因子引起的RPE细胞增生和迁移的影响尚未明确. 目的 探讨As2O3对表皮生长因子(EGF)诱导的ARPE-19细胞增生和迁移的影响.方法 用无血清培养基对RPE细胞系ARPE-19细胞进行培养,将终浓度为0、0.5、1.0、2.0、5.0、10.0和20.0 μmol/L的As2O3分别加入到无血清培养基和含10 mg/L EGF的ARPE-19细胞培养液中作用24 h和48 h,通过噻唑蓝(MTT)比色法检测各培养组ARPE-19细胞活性的吸光度(A)值,以探讨As2O3对细胞的药物毒性作用,并筛选安全、有效的As2O3作用浓度.用10 mg/L EGF加入培养基诱导ARPE-19细胞迁移,分别在培养板中加入0、0.5、1.0、2.0μmol/L As2O3 作用24 h和48 h,并通过划痕试验和Transwell试验检测As2O3对EGF诱导的ARPE-19细胞迁移的影响.结果 MTT法检测发现不同浓度As2O3组作用24 h和48 h后,无血清培养组细胞A值随As2O3浓度的升高而逐渐下降,总体差异有统计学意义(F浓度=38.269,P=0.000;F时间=0.874,P=0.358).与空白对照组(0μmol/LAs2O3组)比较,0.5～ 5.0 μmol/L As2O3组ARPE-19细胞A值的差异均无统计学意义(P＞0.05).对含10 mg/LEGF组的ARPE-19细胞,药物对细胞A值的影响呈现浓度和时间依赖性(F浓度=152.155,P=0.000;F时间=51.649,P=0.000).与对照组比较,0.5～2.0μmol/L As2O3加入24 h和48 h后,A值的变化差异均无统计学意义(P＞0.05),而0.5、1.0、2.0μmol/L As2O3加入10 mg/L EGF诱导的ARPE-19细胞中作用24h和48 h后,A值的变化差异均无统计学意义(F浓度=2.215,P=0.126;F时间 =2.230,P=0.155).5.0 ～20.0 μmol/L As2O3作用于EGF诱导的ARPE-19细胞中作用后,细胞A值明显下降,与空白对照组比较差异均有统计学意义(P＜0.05),5.0～20.0 μmol/L As2O3作用24 h后,对EGF诱导的ARPE-19细胞增生抑制率分别为12％、32％、37％;作用48 h后细胞抑制率分别为39％、44％和53％.划痕试验结果显示,0.5～2.0 μmol/L As2O3对EGF诱导的ARPE-19细胞的横向迁移具有抑制作用.Transwell试验结果表明,0.5～2.0 μmol/L As2O3对10 mg/L EGF诱导的ARPE-19细胞纵向迁移有明显的抑制作用,0.5、1.0、2.0μmol/L As2O3作用12h对ARPE-19细胞的抑制率分别为22％、33％和46％. 结论 As2O3在一定浓度范围内对ARPE-19细胞无毒性作用,2.0 μmol/L以下浓度的As2O3对EGF诱导的ARPE-19细胞增生无明显影响,但可影响细胞的迁移能力,5.0 μmol/L以上浓度的As2O3可明显抑制ARPE-19细胞的增生.     

应用反义寡核苷酸沉默PDGFR-α表达对RPE细胞增生和凋亡的影响

背景 视网膜色素上皮( RPE)细胞能分泌血小板源性生长因子(PDGF),又具有PDGF受体(PDGFR),已有研究表明PDGF对增生性玻璃体视网膜病变(PVR)的形成起着关键性作用. 目的 应用反义寡核苷酸( ASODN)技术抑制血小板源性生长因子受体-α(PDGFR-α)基因的表达,观察其对RPE细胞增生和凋亡的影响.方法 将人RPE细胞株在含质量分数10％胎牛血清的低糖DMEM培养基中进行培养,取对数生长期细胞调节细胞密度为5×105个/孔,接种于96孔板,待细胞生长至80％～90％融合时进行转染.空白对照组不加PDGFR-α ASODN及阳离子脂质体Lipofectamine 2000,1.0μmol/L Lipo-ASODN组、2.0μmol/LLipo-ASODN组使用阳离子脂质体Lipofectamine 2000将靶向PDGFR-α基因的ASODN转染至RPE细胞株.细胞转染48 h后,MTT法检测各组细胞的吸光度(A)值并以A490表示,逆转录聚合酶链反应(RT-PCR)法检测PDGFR-α mRNA在RPE细胞中表达的变化;hoechst 33258荧光染色观察培养细胞的凋亡情况;流式细胞仪检测RPE细胞的细胞周期和凋亡率. 结果 空白对照组、1.0 μmol/L Lipo-ASODN组及2.0μmol/L Lipo-ASODN组RPE细胞的A490值分别为1.45±0.12、1.07±0.06、0.65±0.05,差异有统计学意义(F=97.72,P=0.00),1.0μmol/L Lipo-ASODN组和2.0 μmol/L Lipo-ASODN组RPE细胞A490值明显低于空白对照组,差异均有统计学意义( P=0.00、0.00);2.0 μmol/L Lipo-ASODN组RPE细胞A490值明显低于1.0 μmol/L Lipo-ASODN组,差异有统计学意义(P=0.00).Hoechst 33258荧光染色显示,转染PDGFR-α ASODN后RPE细胞凋亡数量多于空白对照组.流式细胞仪检测表明,转染PDGFR-α ASODN后RPE细胞阻滞于G0/G1期(F=206.70,P=0.00),1.0 μmol/L Lipo-ASODN组和2.0μmol/L Lipo-ASODN组RPE细胞凋亡率均明显高于空白对照组(37.8±1.3 vs 10.5±0.1,61.2±1.9 vs 10.5±0.1)(F=1808.90,P=0.00).PDGFR-α在RPE细胞中的表达随PDGFR-α ASODN浓度的升高有降低的趋势. 结论 利用ASODN技术沉默PDGFR-α基因表达可以显著抑制PVR过程中RPE细胞的增生,并能诱导其凋亡,不同浓度PDGFR-α ASODN转染后能下调PDGFR-α mRNA的表达,PDGFR-α基因的ASODN靶向技术为PVR的基因治疗提供了实验依据.     

神经生长因子对人胚胎视网膜色素上皮细胞生长及其DNA合成的影响

目的　探讨神经生长因子 (NGF)对体外培养的人胚胎视网膜色素上皮 (RPE)细胞的促增殖作用及DNA合成的影响。方法　分别用MTT法测定加入NGF 10 0、2 0 0、30 0 μg/L 48h后人RPE细胞数量的改变和核酸蛋白分析仪测定加入NGF 5 0、10 0、2 0 0、30 0、40 0 μg/L 48h后人RPE细胞DNA质量浓度的变化。 结果　 10 0、2 0 0、30 0 μg/LNGF作用 48h后其细胞增殖的A值分别为 ( 0 2 137± 0 0 2 33)、( 0 2 188± 0 0 181)、( 0 2 32 2± 0 0 16 4) ,与对照组 ( 0 1897± 0 0 15 2 )相比 ,差异有显著性 (q test ,P <0 0 5 ) ;10 0、2 0 0、30 0、40 0 μg/LNGF作用 48h后其细胞DNA质量浓度分别为 ( 981 2 2 0 4± 12 3 5 35 7)、( 1375 8484± 2 44 4 718)、( 16 5 8 70 71± 176 9381)、( 2 35 3 0 86 3± 6 0 9 90 6 4) μg/ml ,与对照组 ( 6 6 6 8188± 14 1 330 2 ) μg/ml相比差异有显著性 (q test,P <0 0 5 )。结论　NGF可促进人RPE细胞增殖及促进细胞DNA合成。     

大鼠Slit2基因慢病毒干扰载体的构建及其对大鼠RPE细胞中Slit2基因的下调作用

背景 年龄相关性黄斑变性(AMD)是老年人致盲的首要原因.目前,AMD的治疗方式在取得显著疗效的同时亦有一定的不足,寻找新的有效治疗靶点是当前的研究热点. 目的 构建大鼠Slit2基因慢病毒干扰载体,筛选有效干扰序列以用于大鼠视网膜色素上皮(RPE)细胞中Slit2基因沉默,为大鼠相关体内实验奠定基础.方法 设计2条大鼠Slit2基因siRNA序列,退火形成DNA,连接形成慢病毒干扰载体并进行测序鉴定.采用三质粒共转染293T细胞法收获慢病毒(Lv-rSlit2-siRNA),用药物筛选法测定病毒悬液滴度.将大鼠RPE细胞分为空白对照组、空病毒组、Lv-rSlit2-siRNA1组和Lv-rSlit2-siRNA2组,根据分组分别用仅有病毒的载体和不同序列的Lv-rSlit2-siRNA载体转染细胞,分别采用实时荧光定量PCR法和Western blot法测定各组细胞中Slit2 mRNA及蛋白的表达以确定Slit2基因的敲减率,筛选有效干扰序列.采用0、100、200和400μmol/L CoCl2孵育大鼠RPE细胞以制备缺氧细胞模型并转染筛选Lv-rSlit2-siRNA2干扰序列,采用实时荧光定量PCR法和ELISA法测定大鼠RPE细胞中血管内皮生长因子A(VEGFA)表达变化及细胞上清液中VEGFA质量浓度.结果 成功构建2条大鼠Slit2基因慢病毒干扰载体,病毒滴度分别为5×108 TU/ml和3×108 TU/ml,转染病毒后72 h于荧光显微镜下观察RPE细胞慢病毒转染率均在70％以上.Lv-rSlit2-siRNA1组和Lv-rSlit2-siRNA2组大鼠RPE细胞中Slit2 mRNA相对表达量分别为0.67±0.09和0.23±0.11,明显低于空白对照组的1.03±0.31和空病毒组的0.92 ±0.07;Lv-rSlit2-siRNA1组和Lv-rSlit2-siRNA2组大鼠RPE细胞中Slit2蛋白相对表达量分别为0.62±0.07和0.49±0.02,明显低于空白对照组的1.00±0.10和空病毒组的0.95±0.11,差异均有统计学意义(均P＜0.01).0、100、200和400 μmol/L CoCl2作用后,空白对照组和Lv-rSlit2-siRNA2组大鼠RPE细胞中VEGFA mRNA的相对表达量明显不同,差异均有统计学意义(F浓度=127.998,P＜0.01;F分组=69.663,P＜0.01),不同浓度CoCl2作用后各组大鼠RPE细胞中VEGFA蛋白相对表达量均明显不同,差异均有统计学意义(F浓度=17.059,P＜0.01;F分组=91.791,P＜0.01).100、200和400 μmol/LCoCl2作用后Lv-rSlit2-siRNA2组大鼠RPE细胞中VEGFA mRNA表达量及蛋白质量浓度均明显低于空白对照组,差异均有统计学意义(均P＜0.01).结论 大鼠Slit2基因慢病毒干扰载体构建成功并筛选出有效干扰重组序列,其能有效下调大鼠RPE细胞中Slit2基因的表达,并抑制缺氧环境下VEGFA在大鼠RPE细胞中的表达.     

Changes in Bruch's membrane in experimental hypercholesteremia in rats

PURPOSE: We investigated the effect of high cholesterol diet for the aging changes in Bruch's membrane of rats. METHODS: After feeding a 4% cholesterol diet for 15 weeks to three young rats 3 months old and four aged rats 23 months old, we observed the morphological changes of Bruch's membrane by electron microscopy, and made a comparison with rats fed an ordinary diet. RESULTS: In one young rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris formed multiple folds separated from the plasma membrane of the endothelium and showed lamellar thickening and crack in some areas. The elastic fiber layer in Bruch's membrane disappeared partly and some new microfibrils appeared. In one aged rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris showed more lamellar thickening with lumps in some parts. Compared with rats fed an ordinary diet, rats fed a high-cholesterol diet showed thickening of the basement membrane and the changes were more severe. CONCLUSIONS: Our data indicated that high-cholesterol diet might promote age-related changes of Bruch's membrane.     

Advances in imaging in oculoplastics

Color Doppler imaging, computed tomography (CT) and magnetic resonance (MR) imaging are the most precious imaging tools for the clinician in the field of oculoplastics. Orbital and facial vasculature, with its dynamic changes and flow velocities seen in orbital varices, carotid-cavernous fistulas, and dural cavernous arteriovenous malformations, is best detected by Color Doppler imaging. Computed tomography remains the dominant imaging modality in the evaluation of orbital trauma. Helical CT axial scanning with multiplanar reconstruction and three-dimensional CT imaging are most helpful in assessing iatrogenic, traumatogenic, and teratogenic orbital abnormalities. Despite its poor histologic specificity, MR imaging provides superior soft tissue contrast, and contrast-enhanced MR imaging has an established role regarding soft tissue tumor infiltration. The greatest value of MR studies in the evaluation of orbital and palpebral tumors is that it has the capacity to show the precise relation between lesions and adjacent structures before the clinician contemplates a surgical approach. Finally, contrast-enhanced MR imaging proved to be a valuable vascularization indicator based upon the extent of relative enhancement within porous orbital implant in anophthalmic socket.     

Follow-up studies in pattern VECP in demyelinating diseases in children

Spectral sensitivity functions and the transient decrease of sensitivity to short wavelengths after the offset of yellow light (transient tritanopia) were measured by increment threshold techniques in patients suffering from hereditary macular degenerations. Color vision defects were determined by arrangement tests and the anomaloscope. Central areolar choroidal dystrophy was found to produce a mild protan defect and to reduce foveal spectral sensitivity throughout the visible spectrum by a factor of 100; it also abolishes transient tritanopia. Electroretinogram (ERG) was normal, electrooculogram (EOG) subnormal. Stargardt's disease, despite numerous fluorescent macular spots, does not abolish transient tritanopia nor does it reduce spectral sensitivity, although scotopic matches were performed on the Nagel anomaloscope. Only in severe, advanced cases was transient tritanopia reduced and spectral sensitivity found to follow the absorption spectrum of rods. Routine ERGs and EOGs were normal. Vitelliform macular degeneration, despite the ophthalmoscopically pronounced dystrophic macula, produced only very small changes in spectral sensitivity and transient tritanopia, although a widened matching range on the Nagel anomaloscope and electrophysiological abnormalities were found. Apparently damage of the retinal circuit which connects long and short wavelength-sensitive cones, caused by hereditary conditions, is different from that caused by retinotoxic drugs.     

Vitrectomy in traumatic cataracts and in the complications of surgery in congenital cataract in children

Vitrectomies were carried out in 35 children with traumatic cataracts and complications of surgery for cataracts, caused by injury to the posterior lenticular capsule and incorporation of its fragments to the vitreous. Complete removal of lenticular rudiments rapidly eliminated phacogenic iridocyclitis and improved visual acuity. Improvement of visual functions was attained in 66.6% cases; in 33.4% cases visual acuity did not change. Hemorrhages to the vitreous cavity occurred in 4 cases with pronounced iridocyclitis; therefore, a corneal approach is preferable for cases with pronounced iridocyclitis.     

Refractive error in children in a rural population in India

PURPOSE: To assess the prevalence of refractive error and related visual impairment in school-aged children in the rural population of the Mahabubnagar district in the southern Indian state of Andhra Pradesh. METHODS: Random selection of village-based clusters was used to identify a sample of children 7 to 15 years of age. From April 2000 through February 2001, children in the 25 selected clusters were enumerated in a door-to-door survey and examined at a rural eye center in the district. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy and autorefraction under cycloplegia, and examination of the anterior segment, media, and fundus. Myopia was defined as spherical equivalent refractive error of at least -0.50 D and hyperopia as +2.00 D or more. Children with reduced vision and a sample of those with normal vision underwent independent replicate examinations for quality assurance in seven clusters. RESULTS: A total of 4414 children from 4876 households was enumerated, and 4074 (92.3%) were examined. The prevalence of uncorrected, baseline (presenting), and best corrected visual acuity of 20/40 or worse in the better eye was 2.7%, 2.6%, and 0.78%, respectively. Refractive error was the cause in 61% of eyes with vision impairment, amblyopia in 12%, other causes in 15%, and unexplained causes in the remaining 13%. A gradual shift toward less-positive values of refractive error occurred with increasing age in both boys and girls. Myopia in one or both eyes was present in 4.1% of the children. Myopia risk was associated with female gender and having a father with a higher level of schooling. Higher risk of myopia in children of older age was of borderline statistical significance (P = 0.069). Hyperopia in at least one eye was present in 0.8% of children, with no significant predictors. CONCLUSIONS: Refractive error was the main cause of visual impairment in children aged between 7 and 15 years in rural India. There was a benefit of spectacles in 70% of those who had visual acuity of 20/40 or worse in the better eye at baseline examination. Because visual impairment can have a significant impact on a child's life in terms of education and development, it is important that effective strategies be developed to eliminate this easily treated cause of visual impairment.