第二章視功能檢查ChapterTwoVisualFunctionExamination課件

第二章視功能檢查

ChapterTwoVisualFunctionExamination視力(visualacuity)即視銳度，它代表形覺功能。通常所說的視力是指中心視力，它反映功能最敏銳的視網(wǎng)膜黃斑中心凹的視力。世界衛(wèi)生組織的標(biāo)準(zhǔn)規(guī)定，較好眼的矯正視力低于0.3為低視力，低于0.05為盲，稱為低視力。Visualacuityistheacuityofvision,whichrepresentstheformfunctionoftheeye.Visualacuityisusuallyreferredtoascentralvisualacuity,whichreflectsthevisualacuityofthefoveacentralisoftheretina.AccordingtotheWHOstandard,correctedvisualacuityofstrongereyelessthan0.3islowvisionandlessthan0.05isblindness.一、視力Ⅰ.VisualAcuity對(duì)于低視力患者，視力是低視力的診斷標(biāo)準(zhǔn)之一，是選擇低視力助視器的主要依據(jù)，并可以評(píng)價(jià)常見眼病治療前后的療效，由于視力檢查對(duì)于低視力患者的重要性，再加上低視力患者本身的眼病會(huì)影響視力檢查，因此，最好由受過專門訓(xùn)練的技術(shù)人員進(jìn)行檢查，如驗(yàn)光師、視光師等。Forlowvisionpatients,visualacuityisoneofthediagnosticstandardsforlowvision.Itisthemainbasisforselectingvisualaidsforlowvision,anditcanbeusedtoevaluatetheeffectofcommoneyediseasesbeforeandaftertreatment.Becauseoftheimportanceofvisualacuityexaminationforlowvisionpatientsandthefactthatlowvisionpatients'eyeconditionscanaffectvisualacuityexamination,itisbesttohavethemperformedbyaspeciallytraineddoctorornurse.視力表是測定視力的主要工具，它是根據(jù)視角(指外界物體上兩點(diǎn)在眼結(jié)點(diǎn)處所夾的角)原理設(shè)計(jì)的，視力檢查的最終目的即是測出眼能辨別兩點(diǎn)時(shí)的最小視角，用這最小視角的倒數(shù)值來表示視力。人眼能分辨出兩點(diǎn)的最小視角是1'視角，即1.0視力。Visionchartisthemaintoolformeasuringvisualacuity.Itisdesignedaccordingtotheprincipleofviewangle(theanglebetweentwopointsonanexternalobjectattheeyenode).Thefinalpurposeofvisionacuityexaminationistomeasuretheminimumviewanglewhentheeyecandistinguishtwopoints,andusethereciprocalvalueoftheminimumviewangletoexpressvision.Iftheminimumviewangleatwhichthehumaneyecandistinguishbetweentwopointsis1'viewangle,thevisualacuityis1.0.檢查視力須兩眼分別進(jìn)行，一般先右后左?？捎檬终苹蛐“逭谏w眼但不要壓迫眼球。視力表須按標(biāo)準(zhǔn)亮度的光線照明。檢查者用桿指著視力表的視標(biāo)，囑被檢者說出或用手勢(shì)表示該視標(biāo)的缺口方向，逐行檢查,找出被檢者的最佳辨認(rèn)行。戴眼鏡者要先查裸眼視力，再查矯正視力。視力的計(jì)算公式為V=d/D,V為視力，d為實(shí)際看見某視標(biāo)的距離，D為正?？匆娫撘晿?biāo)的距離。VisualacuityexaminationforlowvisionVisualacuityexaminationshouldbecarriedoutinbotheyes,usuallyfromrighttoleft.Covertheeyewiththepalmoreyeshade,butdonotpresstheeye.Thechartshallbeilluminatedwithstandardlight.Theexaminerneedstopointtheoptotypeofthevisionchartwitharod,andasksthesubjecttosayorgesturethenotchorientationoftheoptotype,andcheckslinebylinetofindoutthebestidentificationlineofthesubject.Thepersonwhowearsglassesshouldcheckthenakedeyevisionfirst,andthencheckthecorrectedvision.ThecalculationformulaofthevisionisV=d/D,whereVisthevision,distherealdistanceofseeingacertainoptotype,andDisthenormaldistanceofseeingtheoptotype.例如：受檢眼離視力表d為3m，看見實(shí)際應(yīng)用在5m遠(yuǎn)，看見的1.0視標(biāo)，則其視力為3/5(0.6)。Forexample,ifthesubject'seyecansee1.0optotypeatd=3mthatshouldbeseen5mawayfromthevisionchart,thevisionis3/5(0.6).一、低視力的視力檢查Ⅰ.VisualacuityexaminationforlowvisionVisual1.遠(yuǎn)視力的檢查：遠(yuǎn)視力檢查的距離為5m，逐行檢查。當(dāng)?shù)鸵暳颊咴诔Ｒ?guī)檢查距離不能看清視力表上最大的視標(biāo)時(shí)，可以縮短檢查距離，可在3米、1.5米或1米距離測試，這是患者平時(shí)發(fā)揮最佳功能的距離，測出的是患者實(shí)際視力。有時(shí)為了增強(qiáng)患者信心，也可將視力檢查的距離縮短。此外，對(duì)低視力患者一般不用“指數(shù)”作為視力記錄，而是用最大視標(biāo)移近眼的方法測試，記錄為0.02、0.01等。如果在很近處仍不能識(shí)別，則應(yīng)記為手動(dòng)，并同時(shí)標(biāo)明識(shí)別手動(dòng)的最遠(yuǎn)距離。如果眼前手動(dòng)不能識(shí)別，則檢查光感，記錄“光感”或“無光感”。1.

Examinationofdistancevision:Thedistancefordistancevisionexaminationshallbe5m,andtheexaminationshallbeconductedlinebyline.Whenapatientwithlowvisioncannotclearlyseethelargestoptotypeonthevisionchartattheconventionalexaminationdistance,theexaminationdistancecanbeshortened,andtheexaminationdistancecanbeexaminedatdistancesof3m,1.5mor1m.Itisthedistancethatthepatientnormallyperformsthebestfunction,sotheactualvisionofthepatientismeasured.Sometimesthedistanceofthevisualacuityexaminationmaybeshortenedinordertoincreasethepatient’sconfidence.Inaddition,lowvisionpatientsgenerallydonotuse“fingercount”asthevisionrecord,butusethemethodofmovingthemaximumoptotypeneartheeye,therecordis0.02,0.01,etc.Ifitisstillnotrecognizedinaveryshortdistance,itshallberecordedashandmovementandthemaximumdistanceofhandmovementrecognitionshallbeindicated.Ifhandmovementrecognitionisnotpossible,checklightperceptionandrecord“l(fā)ightperception”or"nolightperception".低視力患者視力檢查：分為遠(yuǎn)視力檢查和近視力檢查。Visualexaminationforpatientswithlowvision:farvisionexaminationandnearvisionexamination.第一步：打開視力表電源，放置于受試者對(duì)面5m處，開始檢查。Step1:Turnonthepowersupplyofthevisionchart,placeit5mawayfromthesubject,andstarttheexamination.第二步：先檢查右眼，遮蓋板遮蓋左眼。Step2:Checktherighteyefirstandcovertheleftonewitheyeshade.第三步：受試者從大到小依次讀/指出視標(biāo)方向，積極鼓勵(lì)受試者讀1指出他能看清的最小一行視標(biāo)的方向，在保持檢查距離不變的情況下允許轉(zhuǎn)動(dòng)眼位、頭位、體位以獲得最好視力。當(dāng)一行中半數(shù)以上的視標(biāo)不能被辨認(rèn)時(shí)，停止檢查。Step3:Thesubjectshallread/pointtheoptotypeorientationfromlargetosmall.Theexaminershouldactivelyencouragethesubjecttoread/pointtheorientationofthesmallestlineofoptotypethesubjectcanseeclearly,andallowthesubjecttorotatetheeyeposition,headpositionandbodypositiontoobtainthebestvisionwhilekeepingtheexaminationdistanceunchanged.Whenmorethanhalfoftheoptotypesinarowareunrecognizable,stoptheexamination.第四步：如果受試者在5m檢查距離不能辨認(rèn)出出最大一行的視標(biāo)，可以移至2.5m處檢查;如仍不能讀出最大視標(biāo)，可以移至1m處檢查;如仍不能讀出最大視標(biāo)，則檢查1m至眼前距離的手動(dòng);不能識(shí)別眼前手動(dòng)，則檢查光感。Step4:Ifthesubjectcannotrecognizethelargestlineofoptotypeattheexaminationdistanceof5m,thesubjectcanmoveto2.5mforexamination;ifthemaximumoptotypestillcannotberead,itcanbemovedto1mforexamination;ifthemaximumoptotypestillcannotberead,checkthehanddistancefrom1mtotheeyes;ifthehandmovementinfrontoftheeyescannotberecognized,checkthelightperception.第五步：遮蓋右眼，檢查左眼，重復(fù)上述檢查步驟。Step5:Covertherighteye,examinethelefteye,andrepeatthestepsabove.第六步：雙眼同時(shí)去遮蓋，檢查雙眼視力。Step6:Uncoverbotheyesatthesametime,andcheckthebinocularvision.具體檢查步驟如下：Thespecificcheckstepsareasfollows:2.近視力的檢查：近視力的檢查原理與遠(yuǎn)視力相同，但檢查距離為30cm,可采用自然彌散光線或手電筒做局部照明。如果低視力患者在30cm仍不能看清最大的視標(biāo)，可以將近視力表移近檢查，記錄近視力時(shí)須同時(shí)記錄實(shí)際檢查距離。2.Examinationofnearvision:Theexaminationprincipleofnearvisionisthesameasthatofdistancevision,buttheexaminationdistanceis25-40cm(accordingtotherequirementsofvisionchart),andnaturaldiffuselightorflashlightcanbeusedforlocalillumination.Ifthepatientwithlowvisionstillcannotseethelargestoptotypeatthedistancerequiredbythevisionchart,thenearvisionchartcanbemovedcloserforexamination,andtheactualexaminationdistanceshallberecordedatthesametimewhenrecordingthenearvision.第一步：視力表放置于受試者眼前25cm處。Step1:Thevisionchartshouldbeplaced25cminfrontofthesubject’seye.第二步：先檢查右眼，遮蓋板遮蓋左眼。Step2:Checktherighteyefirstandcovertheleftonewitheyeshade.第三步：受試者從大到小依次讀/指出視標(biāo)方向，積極鼓勵(lì)受試者讀/指出他能看清的最小一行視標(biāo)的方向，在保持檢查距離不變的情況下允許轉(zhuǎn)動(dòng)眼位、頭位、體位以獲得最好視力。當(dāng)一行中半數(shù)以上的視標(biāo)不能被辨認(rèn)時(shí)，停止檢查。Step3:Thesubjectshallread/pointtheoptotypeorientationfromlargetosmall.Theexaminershouldactivelyencouragethesubjecttoread/pointtheorientationofthesmallestlineofoptotypethesubjectcanseeclearly,andallowthesubjecttorotatetheeyeposition,headpositionandbodypositiontoobtainthebestvisionwhilekeepingtheexaminationdistanceunchanged.Whenmorethanhalfoftheoptotypesinarowareunrecognizable,stoptheexamination.第四步：如果受試者在25cm檢查距離不能辨認(rèn)出最大一行的視標(biāo)，可讓受試者自由移動(dòng)檢查距離，直到測出其最高的視力記錄(要標(biāo)出檢查時(shí)的距離)，如仍不能辨認(rèn)出視標(biāo)方向，則進(jìn)一步以指數(shù)手動(dòng)或光感檢查視力。Step4:Ifthesubjectcannotidentifythelargestlineofoptotypeattheexaminationdistanceof25cm,thesubjectmaybeallowedtomovetheexaminationdistancefreelyuntilthehighestvisionrecordismeasured(thedistanceatthetimeofexaminationshallbemarked).Iftheorientationofoptotypestillcannotbeidentified,thevisionshallbefurthercheckedbycountfigureofhandmotionsorlightperception.第五步：遮蓋右眼，檢查左眼，重復(fù)上述檢查步驟。Step5:Covertherighteye,examinethelefteye,andrepeatthestepsabove.第六步：雙眼同時(shí)去遮蓋，檢查雙眼視力。Step6:Uncoverbotheyesatthesametime,andcheckthebinocularvision.具體檢查步驟如下：Thespecificcheckstepsareasfollows:

低視力患者到低視力門診后都要重新進(jìn)行細(xì)致的屈光檢查:以判斷患者視力是否可以通過屈光矯正來提高。臨床實(shí)踐中往往發(fā)現(xiàn)相當(dāng)部分低視力患者，尤其是高度屈光不正的低視力患者，在給予細(xì)致驗(yàn)光后矯正視力能達(dá)0.3以上。

Patientswithlowvisionshouldreceivetherefractiveexaminationagaintodetermineiftheirvisioncanbeimprovedbyrefractivecorrection.Inclinicalpractice,itisoftenfoundthataconsiderablenumberofpatientswithlowvision,especiallythosewithhighrefractiveerror,havecorrectedvisionofmorethan0.3aftercarefulrefraction.（一）客觀驗(yàn)光法（一）Objectiverefraction:

客觀驗(yàn)光法是檢查者用儀器來判斷屈光不正的程度和性質(zhì)住要的方法是檢影法、自動(dòng)驗(yàn)光儀法、角膜曲率計(jì)法等。適用于合作欠佳的患者。

Objectiverefractionisamethodbywhichtheexaminerjudgesthedegreeandnatureoftherefractiveerroroftheexaminedeyethroughobjectiveexamination.Themainmethodsareretinoscopy,autorefraction,keratometryandsoon.Objectiverefractionissuitableforpatientswhocannotcooperatewell.二、眼屈光檢查ⅡRefractiveExamination檢影法是客觀驗(yàn)光的主要方法之一，檢影鏡將光線投射人眼，通過觀察瞳孔區(qū)的影動(dòng)，獲得眼屈光狀態(tài)的信息。

Retinoscopyisoneofthemainmethodsofobjectiverefraction,inwhichthelightisprojectedintotheeyebyaretinoscope,andtheinformationoftherefractivestatusoftheeyeisobtainedbyobservingthelightmovementofthepupilarea.自動(dòng)驗(yàn)光儀是屈光檢查技術(shù)和電子計(jì)算機(jī)技術(shù)結(jié)合起來的產(chǎn)物。操作簡單、速度快，適用于集體普查。但去除調(diào)節(jié)作用不夠完全，因此檢查結(jié)果只能作臨床參考，不能直接做配鏡處方。

Theautorefractorisacombinationofrefractiveexaminationtechnologyandcomputertechnology.Ithassimpleoperationandhighspeed,andsuitableforcollectivegeneralsurvey.However,removalofaccommodationisnotcompletelyenough,sotheexaminationresultcanonlybeusedasaclinicalreference,andcannotbedirectlyuseforfittingprescription.(二)主觀驗(yàn)光法（二）Subjectiverefraction:主觀驗(yàn)光是以患者的視力變化為主要觀察目標(biāo)的，因此必須取得患者的合作，也就是說，主觀驗(yàn)光法適用于能和檢查者合作的患者。

Theprimaryobjectiveofthismethodisthechangeinvisionofthepatient,sothecooperationofthepatientmustbeobtained,i.e.thesubjectiverefractionissuitableforthepatientwhocancooperatewiththeexaminer.主觀驗(yàn)光法一般是將不同的鏡片放在患者眼前，比較視力的改變，來獲得眼屈光狀態(tài)的信息。在驗(yàn)光前應(yīng)先了解患者的年齡及屈光狀態(tài),并作為此次驗(yàn)光的參考主觀驗(yàn)光法包括球鏡片法，柱鏡法、云霧法、散光表法、交叉柱鏡法、紅綠二色試驗(yàn)法和自動(dòng)主觀驗(yàn)光儀法等。(三)睫狀肌麻痹驗(yàn)光(三)

Cycloplegicrefraction由于眼的調(diào)節(jié)狀態(tài)會(huì)影響屈光的檢測，因此，為了準(zhǔn)確獲得人眼調(diào)節(jié)靜止?fàn)顟B(tài)下的眼屈光狀態(tài)，需使用睫狀肌麻痹劑將睫狀肌麻痹。這是種比較準(zhǔn)確的獲得屈光信息的方法需要指出的是:對(duì)于低視力患者，必須在散瞳驗(yàn)光后睫狀肌麻痹恢復(fù)后，再對(duì)低視力患者進(jìn)行助視器的驗(yàn)配。成功率會(huì)有大幅度提高。

Sincetheaccommodationstateoftheeyeaffectstherefractiveexamination,cycloplegicrefractionisrequiredtoaccuratelyobtaintherefractivestatusofthehumaneyeatstaticaccommodationstate.Thisisamoreaccuratemethodtoobtainrefractiveinformation.Itshouldbepointedoutthatforpatientswithlowvision,thefittingofvisualaidsmustbeperformedaftertherecoveryofcycloplegia.Thesuccessratewillbegreatlyimproved.

第一步：戴上合適瞳距的試鏡架，右眼前置有磨砂鏡片和測試鏡片，遮擋左眼。

Step1:Wearatrialframewithappropriatepupillarydistance,placefrostedlensandexaminationlensinfrontoftherighteye,andcoverthelefteye.第二步：遠(yuǎn)近視力檢查。Step2:Distanceandnearvisionexamination.第三步：球鏡度數(shù)確定①根據(jù)視力選擇較大度數(shù)的正負(fù)球鏡(如6.0D)作為起始驗(yàn)光球鏡置于右眼前，讓受試者比較哪個(gè)鏡片下視標(biāo)更清晰，并將帶來清晰感覺的球鏡添加在試鏡架上;②重復(fù)上述步驟，直至相反符號(hào)球鏡清晰;③試鏡架上添加步驟②中檢出球鏡一半度數(shù)球鏡;④檢查矯正視力。如視力無改善，停止檢查;如矯正視力有改善，以步驟③中所加度數(shù)為起始驗(yàn)光球鏡重復(fù)步驟①②③④，直至獲得最佳矯正視力。Step3:Determinationofthediopterofsphericallenses:(1)Selectapositiveornegativesphericallenswithalargerdiopter(suchas6.0D)accordingtothevisionastheinitialrefractionsphericallenstobeplacedinfrontoftherighteye,andaskthesubjecttocomparewhichlenshasaclearerloweroptotype,andaddthesphericallenswithclearfeelingtotheexaminationframe;(2)Repeattheabovestepsuntilthesphericallenswiththeoppositesignisclear;(3)Addthesphericallenswithhalfthediopterofthesphericallensdetectedinstep(2)totheexaminationframe;(4)Checkthecorrectedvision.Ifthevisionisnotimproved,stoptheexamination;ifthecorrectedvisionisimproved,startfromthediopterinstep(3)astheinitialrefractionsphericallens,andrepeatsteps（1）（2）（3）（4）untilthebestcorrectedvisionisobtained.第四步：柱鏡度數(shù)確定用Jackson交叉柱鏡(JCC)確定散光的軸向和散光量。根據(jù)球鏡全矯后的視力選擇合適度數(shù)的JCC開始驗(yàn)光，操作方法同常規(guī)JCC操作方法一致。起始度數(shù)可高于常規(guī)檢查。Step5:DeterminationofthediopterofcylindricallensisconductedwithJacksonCrossedCylindricallens(JCC):Determinetheaxisandamountofastigmatism.Accordingtothevisionaftersphericallenstotalcorrection,choosetheappropriatediopterofJCCandstartrefraction,andtheoperationmethodisthesameastheroutineJCCoperationmethod.Thestartingdioptercanbehigherthantheroutineexamination.第五步：再次調(diào)整球鏡重復(fù)步驟三。Step5:Repeatprocedure3againbyadjustingthesphericallens.第六步：重復(fù)步驟三~步驟五，檢查左眼屈光度數(shù)。Step6:Repeatsteps1tostep5tocheckthediopterofthelefteye.低視力患者的主覺驗(yàn)光步驟：Mainvisionoptometrystepsforpatientswithlowvision:

對(duì)比敏感度檢查

引入調(diào)制傳遞函數(shù)概念，根據(jù)灰度調(diào)制曲線的變化制成寬窄、明暗不同的條柵圖作為檢查視標(biāo)，以此反映空間、明暗對(duì)比二維頻率的形覺功能，調(diào)制曲線的寬度變化，反映條柵的空間函數(shù)；調(diào)制曲線的高度變化，反映條柵的明暗對(duì)比函數(shù)。以空間頻率為橫軸，它的對(duì)比敏感度函數(shù)為縱軸，可以繪制出對(duì)比敏感度函數(shù)曲線，又稱調(diào)制傳遞函數(shù)曲線。該曲線可以較完整地反映視功能。正常人此曲線為一倒U形，或山形、鐘形。Incontrastsensitivityfunction(CSF)examination,theconceptofmodulationtransferfunctionisintroduced.Accordingtothechangeofgray-scalemodulationcurve,abar-gridpatternwithdifferentwidthandbrightnessismadetobeusedastheexaminationoptotype,soastoreflecttheformsensefunctionofspatialandlight-darkcontrasttwo-dimensionalfrequency.Thechangeofthewidthofthemodulationcurvereflectsthespatialfunctionofthebargrating,andthechangeoftheheightofthemodulationcurvereflectsthelight-darkcontrastfunctionofthebargrating.TakingthespatialfrequencyasthehorizontalaxisandtheCSFastheverticalaxis,theCSFcurve,alsocalledmodulationtransferfunctioncurve,canbedrawn.Thecurvecancompletelyreflectthevision.ThecurveofanormalpersonisaninvertedU-shape,oramountain-shapedorbell-shapedcurve.三、對(duì)比敏感度檢查Ⅲ.ContrastSensitivityFunctionExamination視力檢查反映的是高對(duì)比度（黑白反差明顯）下的分辨能力。普通視力表所測得的視力，只表明在視覺對(duì)比敏感度曲線上最后一個(gè)點(diǎn)的情況，即在最大或100%對(duì)比情況下，測定識(shí)別微小細(xì)節(jié)（高空間頻率）的能力。而對(duì)比敏感度函數(shù)是在不同空間頻率下檢測所能看清正弦波光柵的倒數(shù)，反映了人眼對(duì)不同對(duì)比度情況下真實(shí)的分辨能力，較好地反映了自然生活狀態(tài)下的視覺功能狀態(tài)。Visualacuityexaminationsreflectresolutionathighcontrast(obviouscontrastbetweenblackandwhite).Visionmeasuredonacommonchartindicatesonlytheabilitytoidentifysmalldetails(highspatialfrequency)atthelastpointonthevisioncontrastsensitivitycurve,i.e.,atmaximumor100%contrast.TheCSFisthereciprocalofthesinewavegratingwhichcanbeseenclearlyunderdifferentspatialfrequencies,whichreflectstherealresolvingpowerofhumaneyesunderdifferentcontrastconditionsandbetterreflectsthevisionstateunderthenaturallifestate.例如，某些眼病識(shí)別白紙黑字視力表正常，而難以識(shí)別灰紙黑字的視力表。某些疾病進(jìn)行視力檢查仍在正常范圍，而對(duì)比敏感度檢查的曲線可出現(xiàn)異常，特別是在高空間頻率段的明暗分辨力下降。Forexample,someeyediseasesrecognizewhitepaperandblacklettersasnormal,butitisdifficulttorecognizegraypaperandblackletters.Insomediseases,thevisualfunctionexaminationisstillinthenormalrange,whiletheCSFcurvemaybeabnormal,especiallyinthehighspatialfrequencyrange.常用的檢査方法，有VCTS6000或VCTS6500對(duì)比敏感度測試卡或?qū)Ρ让舾卸葴y試儀等。CommonexaminationmethodsincludeVCTS6000orVCTS6500CSFcardorCSFtestinginstrument,etc.測試卡橫分5排，分別標(biāo)明A、B、C、D、E,分別代表不同空間頻率。A?E各排均有8個(gè)不同對(duì)比敏感度值的條柵圖，條柵圖有垂直、左斜、右斜3種方向。第9個(gè)是無條柵圖為空白圖。1?8圖的對(duì)比敏感度值逐漸增加。檢查時(shí)，先査右眼，再查左眼。VCTS6000檢查距離為45cm、VCTS6500檢查距離為3m。先從A排圖1看，當(dāng)患者認(rèn)出圖1條柵方向后，再依次看圖2、圖3……直到被檢查者能看清的最后一個(gè)圖，將此圖號(hào)記錄在記錄紙上，再用同樣的方法檢查B、C、D、E各排，并記錄，最后得出該患者的對(duì)比敏感度曲線。Theexaminationcardishorizontallydividedinto5rows,markedwithA,B,C,DandE,whichrespectivelyrepresentdifferentspatialfrequencies.Thereare8barswithdifferentcontrastsensitivityvaluesinrowsAtoE.Thebarshave3directions:vertical,leftobliqueandrightoblique.The9thistheblankgraphwithoutbars.ThecontrastsensitivityvaluesofFigures1-8increasegradually.Whenexamining,examinetherighteyefirstandthenthelefteye.Theexaminationdistanceis45cmfortheVCTS6000and3mfortheVCTS6500.Firstlookatthefigure1inrowA,whenthepatientrecognizesthedirectionofthebargridinfigure1,thenlookatthefigure2andfigure3inturnuntilthesubjectcanseethelastfigureclearly,recordthefigurenumberontherecordpaper,thenchecktherowsB,C,DandEwiththesamemethodandrecordit,andfinallyobtaintheCSFcurveofthepatient.對(duì)比敏感度的檢查，對(duì)于眼科臨床，特別是低視力門診非常重要。對(duì)比敏感度的檢查可以作為評(píng)價(jià)各種疾病的視網(wǎng)膜功能的指標(biāo)之一,并可早期發(fā)現(xiàn)疾病、預(yù)測術(shù)后視力效果對(duì)于低視力患者，也可以通過對(duì)比敏感度的監(jiān)測，提供視覺疾病的鑒別和病情監(jiān)測，判斷整個(gè)視覺系統(tǒng)的功能狀態(tài)。

Contrastsensitivityfunctionexaminationisveryimportantinophthalmologyoutpatientdepartment,especiallyinlowvisionclinic.Thecontrastsensitivityfunctionexaminationcanbeusedasoneoftheindexesforevaluatingtheretinalfunctionofvariousdiseases,andcanbeusedforearlydetectionofdiseasesandpredictionofpostoperativevisioneffect;forpatientswithlowvision,themonitoringofcontrastsensitivityfunctioncanalsobeusedtoprovideidentificationofvisiondiseasesandmonitoringofdiseaseconditions,soastojudgethefunctionalstateofthewholevisionsystem.①動(dòng)態(tài)視野檢査：用大小不同的視標(biāo)，從視野周邊部不同方向向中心移動(dòng)，記錄被檢査者剛能感受到視標(biāo)出現(xiàn)或消失的點(diǎn)。光敏度相同的點(diǎn)構(gòu)成了該視標(biāo)檢測的等視線，而由不同視標(biāo)撿測出的等視線繪成了“視野島”。動(dòng)態(tài)視野的優(yōu)點(diǎn)是檢查速度快，適用于周邊視野的檢查：缺點(diǎn)是小的、旁中心相對(duì)暗點(diǎn)發(fā)現(xiàn)率低。①Kineticperimetry:Usedifferentsizesofoptotypes,movefromtheperipheralpartofthevisualfieldtothecenterindifferentdirections,andrecordthepointwherethesubjectcanjustfeeltheappearanceordisappearanceoftheoptotypes.Thepointswiththesamephotosensitivityconstitutethevisualisopter,andthevisualisopterdetectedbydifferentoptotypesisdrawnasthe"visualfieldisland".Thedynamicperimetryhastheadvantagesoffastexaminationspeedandsuitabilityfortheexaminationofperipheralvisualfields;thedisadvantagesarethatthedetectionrateofthesesmallandparacentralrelativescotomaislow.②靜態(tài)視野檢查：在視屏的各個(gè)設(shè)定點(diǎn)，不動(dòng)視標(biāo)，通過逐漸增加視標(biāo)的亮度，記錄被檢查者感受到的光亮度，也就是該點(diǎn)的閾值或視網(wǎng)膜敏感度。靜態(tài)視野是以對(duì)光的敏感度來對(duì)視野的深度作出定量分析。②Staticperimetry:Ateachsetpointofthevideoscreen,theoptotypeisnotmoved,andthebrightnesssensedbythesubjectisrecordedbygraduallyincreasingthebrightnessoftheoptotype,i.e.thethresholdvalueorretinasensitivityofthepoint.Thestaticperimetryisaquantitativeanalysisofthedepthofthefieldofviewwithsensitivitytolight.四、視野檢查Ⅳ.

Perimetry1.對(duì)比法：是以檢査者的正常視野與被檢查者的視野進(jìn)行比較的一種簡便方法。1.Contrastmethod:Itisasimplemethodtocomparethenormalvisualfieldofthesubjectwiththatofthesubject.具體方法為檢査者與被檢者面對(duì)面而坐，距離約lmo若檢查右眼時(shí)，被檢者遮左眼，右眼注視醫(yī)生的左眼；而醫(yī)生遮右眼，左眼注視被檢者的右眼。醫(yī)生將手指置于自己與被檢者之間等距離處，分別從各方位向中央移動(dòng)，囑被檢者發(fā)現(xiàn)手指出現(xiàn)時(shí)即告之，這樣檢查者就能以自己的正常視野比較被檢者視野的大致情況。該方法不需要任何設(shè)備，簡便易行，但所獲得的結(jié)果較粗略，無法記錄。只能發(fā)現(xiàn)較大的周邊視野缺損。適用于兒童、智力低下者和臥床行為不便的受檢查者或大量體檢時(shí)。Thespecificmethodisthattheexaminerandthesubjectsitfacetoface,andthedistanceisabout1m.Whenexaminingtherighteye,thesubjectcoversthelefteyeandtherighteyelooksatthedoctor'slefteye,whilethedoctorcoverstherighteyeandthelefteyelooksattherighteyeofthesubject.Thedoctorplacesthefingeratanequaldistancebetweenhimselfandthesubject,movesfromeachsidetothecenter,andinstructsthesubjecttoreporttheappearanceofthefinger,sothattheexaminercancomparethegeneralsituationofthesubject'svisualfieldwiththatoftheexaminer.Themethoddoesnotrequireanyequipmentandissimpleandeasytoimplement,buttheobtainedresultsarecrudeandcannotberecorded.Onlylargeperipheralvisualfielddefectscanbefound.Itissuitableforchildren,personswithmentalretardationandthosewhoarebedriddenwithinconvenientbehaviorsorforalargenumberofphysicalexaminations.(一)常用的視野檢查的方法(I)CommonMethodofPerimetry2.平面視野計(jì)：是一種檢測中心30°視野的簡便方法，發(fā)現(xiàn)較小的視野缺損對(duì)于低視力患者的病因診斷非常有意義。方法是黑色屏布Im或2m見方，中心為注視點(diǎn)，屏兩側(cè)水平徑線15°?20°,用黑線各縫一豎圓示生理盲點(diǎn)。檢查時(shí)用不同大小的視標(biāo)繪出各自的等視線。2.Flatperimeter:Itisasimplemethodofdetectingthecentral30°visualfield.Thefindingofsmallvisualfielddefectsisverysignificantfortheetiologicaldiagnosisofpatientswithlowvision.Themethodisthattheblackscreenclothis1mor2msquare,thecenteristhefixationpoint,thehorizontalradiallineonbothsidesofthescreenis15°-20°,andtheblacklineissewedwithaverticalcircletoshowthephysiologicalblindspot.Duringtheexamination,differentsizesofsightmarkscanbeusedtodrawtherespectivevisualisopter.3.弧形視野計(jì)：是一種簡便的動(dòng)態(tài)檢測周邊視野的方法。該視野計(jì)為半徑33cm的半環(huán)弧形板，檢查時(shí)，被檢查眼注視中心目標(biāo)，另一眼被遮蓋，檢査者沿弧的內(nèi)側(cè)面由周邊向中央緩慢移動(dòng)不同大小、不同色澤的視標(biāo)，直到被檢查眼看到視標(biāo)，記錄弧形視野計(jì)上所標(biāo)明的度數(shù)。3.Arcperimeter:Itisasimpleandconvenientmethodfordynamicallydetectingtheperipheralfieldofview.ThePerimeterisasemi-annulararc-shapedplatewiththeradiusof33cm;duringexamination,anexaminedeyelooksatacentraltarget,andtheothereyeiscovered;anexaminerslowlymovesoptotypeswithdifferentsizesanddifferentcolorsfromtheperipherytothecenteralongtheinnersidesurfaceofthearcuntiltheinspectedeyeseestheoptotypes;andthedioptermarkedonthearcPerimeterisrecorded.4.Amsler方格表該表為10cm見方的黑底自線方格表，檢查距離為33cm,相當(dāng)于10°范圍的中心視野。其縱橫邊20x20個(gè)方格，其中央的白色小圓點(diǎn)為注視點(diǎn)。此方法用于檢査中心10°范圍的視野，特別是對(duì)黃斑疾病的檢查具有重要意義。黃斑病變者會(huì)感到中央暗影遮蓋、直線扭曲、方格大小不一等。檢查方法簡便易行。4.Amslergrid:Thisisa10cmsquareblack-groundlinegridwithanexaminationdistanceof33cm,correspondingtoacentralfieldofviewina10°range.Itsverticalandhorizontalsidesare20×20squares,andthesmallwhitedotinthecenteristhefixationpoint.Themethodisusedforcheckingthevisualfieldinacentralrangeof10°,andparticularlyhasimportantsignificancefordetectingmaculardiseases.Peoplewithmaculopathymayexperiencecentralshading,distortedlines,andgridsizes.Theexaminationmethodissimpleandfeasible.5.Goldmann視野計(jì)為投射式半球形視野計(jì)，視標(biāo)大小、亮度以對(duì)數(shù)梯度變化，能精確控制；背景照度為31.5asbo視標(biāo)不是沿著一條子午線移動(dòng)，可任意變換視標(biāo)的運(yùn)動(dòng)方向。檢查者可通過望遠(yuǎn)鏡監(jiān)視被檢査者的眼球位置，并記錄被檢查者按鈕錯(cuò)誤。它具有檢查準(zhǔn)確、敏感，且重復(fù)性好的優(yōu)點(diǎn)。5.Goldmannperimeter:Itisaprojectionhemisphericalperimeter.Thesizeandbrightnessoftheoptotypechangeinlogarithmicgradient,andcanbeaccuratelycontrolled;Thebackgroundilluminationis31.5asb.Theoptotypedoesnotmovealongameridian,anditsmovingdirectioncanbechangedarbitrarily.Theexaminercanmonitortheeyepositionofthesubjectthroughthetelescopeandrecordthebuttonerrorofthesubject.Ithastheadvantagesofaccurateandsensitiveexaminationandgoodrepeatability.6.自動(dòng)視野計(jì)：是由電子計(jì)算機(jī)程序控制的靜態(tài)定量視野計(jì)。它通過檢測被檢查者對(duì)光的敏感度來定量分析和描述視野缺損的情況、定量測定視網(wǎng)膜光閾值。該視野計(jì)具有針對(duì)不同疾病的檢査程序，如青光眼、黃斑疾病等。6.Automaticperimeter:Itisastaticquantitativeperimetercontrolledbyanelectroniccomputerprogram.Itquantitativelyanalyzesanddescribesthesituationofvisualfielddefectandquantitativelydeterminestheretinalightthresholdbydetectingthesensitivityofthesubjecttolight.Theperimeterhasproceduresfordifferentdiseases,suchasglaucoma,maculardisease,etc.7.黃斑微視野檢査：傳統(tǒng)視野以穩(wěn)定的中心凹固視為前提，而黃斑疾病通常是旁i中心固視，不穩(wěn)定的偏心固視限制了傳統(tǒng)視野測量黃斑暗點(diǎn)的準(zhǔn)確性。微視野計(jì)結(jié)合了眼底照相與自動(dòng)視野檢測技術(shù)，將視網(wǎng)膜敏感度地圖與眼底圖像直接對(duì)應(yīng)，實(shí)現(xiàn)了結(jié)構(gòu)檢査與功能檢測的結(jié)合。其眼位追蹤系統(tǒng)可即時(shí)監(jiān)測固視，自動(dòng)補(bǔ)償眼動(dòng)，從而精確測定黃斑部位的功能，確定優(yōu)先視網(wǎng)膜注視點(diǎn)，通過助視器使優(yōu)先視網(wǎng)膜注視點(diǎn)更好發(fā)揮功能。7.Macularmicroperimetry:Stablefovealfixationistheprerequisiteforthetraditionalperimetry,whileparacentralfixationiscommoninmaculardiseases,andunstableeccentricfixationlimitstheaccuracyoftheconventionalperimetryinmeasuringthemacularscotoma.Themicroperimetercombinesfundusphotographyandautomaticperimetrytechnology,directlycorrespondstheretinasensitivitymaptothefundusimage,andrealizesthecombinationofstructureexaminationandfunctiondetection.Theocularpositiontrackingsystemcanimmediatelymonitorfixation,automaticallycompensateeyeballmovement,therebyaccuratelymeasuringthefunctionofthemacula,determiningthepreferentialretinafixationpoint,andenablingthepreferentialretinafixationpointtofunctionbetterthroughthevisualaid.正常人動(dòng)態(tài)視野的平均值為：上方56°,下方74°,鼻側(cè)65°,顳側(cè)91°。即顳側(cè)視野最廣，上方視野最窄。正常的顏色視野以白色最廣，依次為藍(lán)色、紅色、綠色遞減。視野的大小受視標(biāo)的大小、顏色、照明度和檢查技術(shù)的影響，并且檢查者的瞼裂大小、鼻梁高低、眶緣凸度、瞳孔大小、頭位