简介:目的采用不同色彩多焦视网膜电图(mfERG)刺激模式刺激正常眼黄斑部视网膜,观察不同刺激模式mfERG的波形改变及其特征,为将不同色彩刺激模式mfERG应用于黄斑疾病的检测提供正常基线标准和评估检查的可行性。方法分别采用黑/白刺激模式、黑/红刺激模式和黑/绿刺激模式对19例正常视力成年志愿者进行检测,比较分析一阶kernel反应(FOK)的平均反应密度和峰时变化特征,以及稳态闪烁光反应(flicker-30Hz)的平均反应密度和峰时的变化特征。结果正常人FOK以及flicker-30Hz1~5环P1波潜时与刺激色彩的亮度呈负相关,而P1波平均反应密度与刺激色彩亮度呈正相关,P1波峰时和平均反应密度与平均亮度均呈线性回归关系,表现为其亮度特征。结论不同色彩刺激模式存在亮度效应,由不同色彩的不同亮度特征性改变可以客观反映黄斑区不同亮度通道的功能情况。
简介:目的利用电生理方法,鉴定大鼠视网膜Muller细胞钙通道,进而研究慢性眼内压增高对Muller细胞钙通道电流的影响。方法在急性分离的大鼠Muller细胞上,利用全细胞膜片钳的电压钳技术记录钙通道电流。采用结扎巩膜上静脉的方法制备大鼠高眼压模型。结果当细胞外液中不含二价阳离子时,可以记录到电流幅度较大的钙通道介导的Na+流。该电流可被L-型钙通道阻断剂nimodipine和T-钙通道阻断剂mibefradil可逆地压抑到加药前的(39.8±5.4)%(P〈0.001)和(46.7±8.7)%(P〈0.001)。与假手术组相比,高眼压术后1周、2周和4周的大鼠视网膜Mtiller细胞钙通道的电流幅度没有明显的变化。然而,电流成分分析发现,与对照组相比,高眼压大鼠Muller细胞的nimodipine敏感电流呈降低的趋势[1周:(70,9±13.3)%;2周:(70.5±21.9)%;4周:(69.2±23.9)%],而mibefradil敏感的电流在高眼压术后1周和2周呈增高趋势[(157.5±21.2)%和(158.6±35.5)%],4周时趋于正常(109.2±37.9)%。结论大鼠视网膜Mailer细胞功能性表达L-型和T-型钙通道。慢性眼内压增高导致L-型钙通道电流减小,T-型钙通道电流增大,从而增加胞内钙,共同参与Mtiller细胞的去极化和激活。
简介:AIM:Todefinetheultrasonographicstructureofnormallowereyelidanatomiccompartmentsandtheirspacialrelationshipindynamicmotion.METHODS:Highresolutionultrasound(15MHz)wasperformedonthelowereyelidsof7normalsubjects.Movementsofthelowereyelidanditscompartmentswerevisualizedwithultrasound.Inaddition,themaximalexcursionareaofthelowereyelidfatcompartmentsandretractormotionswasmeasuredbeforeandaftermotion.RESULTS:Theorbicularismusclecouldbeseenasanecholucentstructurebetweenthedermisandtheechodencefatpads.Lowereyelidfatpadseemstobedividedinto2compartmentsasrangeofmotionanddirectionofmovementofeachofthemvaries.Itseemsthatthesecompartmentshavealsodifferentbehavior.Themeasuredprofileareaofthevisiblenormallowereyelidfatpadsduringmovementofglobefromup-gazetodown-gazedecreasedby50%.Orderofmovementoflowereyelidstructuresseemstobeasfollows:afterglobemovementfistweseeretractormovement,anteriororbitalfatpad,thenskinandseptum,andfinallymovementofinferiorfatpad.CONCLUSION:Ultrasoundrepresentsanoninvasivetoolforthevisualizationoflowereyelidmorphology.Expandingitsapplicationcouldhelpusunderstandthecompartmentalchangesinphysiologicaleyelidmovement,inaginganddiseasedstudypopulations,aswellasassessoperativeoutcomes.
简介:AIM:Toinvestigatetheaccuracyofintraocularpressure(IOP)asmeasuredbyaReichertOcularResponseAnalyzer(ORA),aswellastherelationshipbetweencentralcornealthickness(CCT)andIOPasmeasuredbyORA,Goldmannapplanationtonometry(GAT),anddynamiccontourtonometry(DCT).·METHODS:Atotalof158healthyindividuals(296eyes)werechosenrandomlyformeasurementofIOP.AfterCCTwasmeasuredusingA-ultrasound(A-US),IOPwasmeasuredbyORA,GAT,andDCTdevicesinarandomizedorder.TheIOPvaluesacquiredusingeachofthethreetonometrieswerecompared,andtherelationshipbetweenCCTandIOPvalueswereanalyzedseparately.TwoIOPvalues,Goldmann-correlatedIOPvalue(IOPg)andcorneal-compensatedintraocularpressure(IOPcc),weregotusingORA.ThreegroupsweredefinedaccordingtoCCT:1)thincornea(CCT<520μm);2)normal-thicknesscornea(CCT:520-580μm);and3)thickcornea(CCT>580μm)groups.·RESULTS:Innormalsubjects,IOPmeasurementswere14.95±2.99mmHgwithORA(IOPg),15.21±2.77mmHgwithORA(IOPcc),15.22±2.77mmHgwithGAT,and15.49±2.56mmHgwithDCT.Meandifferenceswere0.01±2.29mmHgbetweenIOPccandGAT(P>0.05)and0.28±2.20mmHgbetweenIOPccandDC(P>0.05).TherewasagreatercorrelationbetweenIOPccandDCT(r=0.946,P=0.000)thanthatbetweenIOPccandGAT(r=0.845,P=0.000).DCThadasignificantcorrelationwithGAT(r=0.854,P=0.000).GATwasmoderatelycorrelatedwithCCT(r=0.296,P<0.001),whileIOPccshowedaweakbutsignificantcorrelationwithCCT(r=0.155,P=0.007).TherewasastrongnegativecorrelationbetweenCCTandthedifferencebetweenIOPccandGAT(r=-0.803,P=0.000),withevery10increaseinCCTresultinginanincreaseinthisdifferenceof0.35mmHg.Thethickcorneagroup(CCT>580μm)showedtheleastsignificantcorrelationbetweenIOPccandGAT(r=0.859,P=0.000);whilethethincorneagroup(CCT<520μm)hadthemostsignificantcorrelationbetweenIOPccandGAT(r=0.926,P=0.000).ThecorrelateddifferencesbetweenIOPccan
简介:目的利用Micro-CT扫描数据建立中耳听骨链三维有限元模型。方法用Micro—CT扫描成人颞骨标本,将获得的图像数据通过MicroView、Mimics等软件进行三维重建。再将模型转入其有限元分析(finiteelementanalysis,FEA)模块的Remesh环境中进行调整、细化及面网格优化,通过SOLIDEWORK软件转换为实体网格。结果初步形成的三维几何模型可较清晰地辨别鼓室腔、听小骨和内耳系统,但部分图像不同程度存在噪点。最终形成了FEA软件可识别的成人中耳听骨链三维有限元网格模型,网格划分后的听骨链有限元模型中,完整听骨链的节点数降低,由原来包括805个不合理节点在内的12498个节点降低到2050个,在此基础上建立的有限元模型共1350个8节点四面体单元。结论结合Micro—CT技术及Mimics软件的三维建模方法可以快速获得较精确的听骨链三维数据,是建立听骨链三维有限元模型的有效途径。(中国眼耳鼻喉科杂志,2009.9.83。85)
简介:AIM:Tofindasimplemathematicalcorrelationbetweenthelensbasecurve(BC)andkeratometryfindings(krf).METHODS:Thisretrospectivestudyincluded400keratoconiceyes(350patients)previouslyfitwithrigidcontactlensesatanacademiceyecenteroverafiveyearperiod.Thepatientswereclassifiedintofivegroupsbasedonthekeratometryfindings(krf<7,krf:7-8,krf>8,krf-krs(differencebetweentwokeratometry;flatandsteep)=0.3-0.6,krf-krs>0.6mmasgroups1to5,respectively.MultivariatelinearregressionandMunro’scorrelationcoefficientwereemployedtodefertheformulas.RESULTS:Alinearcorrelationcouldbefoundinallgroupsexceptforpatientsingroup3.Forgroup1,BC=0.211×krf+5.904.Forgroup2,BC=0.456×krf+4.160.Forgroup4,BC=0.321×krf+5.219.Forgroup5,BC=0.337×krf+5.090.CONCLUSION:ThedevelopmentofnewformulasforRGPfittingenablesophthalmologiststoworkwithconfidenceandpreventsunnecessaryandfrequentlenstrials.Thecustomarylensfittingmethodsareneededtobereplacedbynewformulas,whichhelptosavetimeandcosts.
简介:AIM:Todescribethedesignandpreliminaryresultsofthehospitalbasedepidemiologicalstudyfordiabeticretinopathy(HBESDR),anongoingepidemiologicalstudytoestimatetheprevalenceofdiabeticretinopathy(DR)andtoelucidatetheclinical,anthropometric,biochemicalandanyotherriskfactorsassociatedwithdiabeticretinopathy.METHODS:Totally2000diabeteswillberecruitedfromtheDiabeteseyeclinicintheFirstAffiliatedHospitalofChinaMedicalUniversity.AllsubjectsunderwentbloodsugarestimationandOralGlucoseToleranceTesttodiagnosediabetes.Alldiabeteswouldundergocompletequestionnaire,acomprehensiveeyeexamination.Bloodandurinewouldbecollectedforbiochemicalinvestigations.AllfundusphotographsforanyDRwillbegraded.Participantswhoneedtreatmentwillbesenttotheophthalmicclinicandfollow-upintervalprogramforallsubjectswillbesuggested.Acomputerizeddatabaseiscreatedfortherecords.RESULTS:Todate,1174diabeteshavebeenrecruited,therewere350(29.81%)DRinalldiabetes,mostofthemwerewithmildnon-proliferativediabeticretinopathy(NPDR)(139,39.71%);71(20.29%)moderateNPDR,66(18.86%)severeNPDR,74(21.14%)proliferativediabeticretinopathy(PDR).Females,longerdurationofdiabetes,familyhistoryofdiabetesandhypertensionhadastatisticallysignificantincreaseinriskofanyDR.CONCLUSION:ThestudyisexpectedtoprovideanestimateoftheoverallprevalenceofDRandtheprevalencewithdifferentdurationofdiabetesandalsoabetterunderstandingoftheriskfactorsassociatedwithDR.