医学资料 眼科 Wills Manual Chapter 11_第1页
医学资料 眼科 Wills Manual Chapter 11_第2页
医学资料 眼科 Wills Manual Chapter 11_第3页
医学资料 眼科 Wills Manual Chapter 11_第4页
医学资料 眼科 Wills Manual Chapter 11_第5页
已阅读5页,还剩93页未读 继续免费阅读

下载本文档

版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领

文档简介

Chapter11

Retina

11.1PosteriorVitreousDetachment

PosteriorVitreousDetachment

Symptoms

Floaters(ucobwebs,““bugs,"or"spots”thatchangepositionwith

eyemovement),blurredvision,flashesoflight,whicharemorecommon

indimilluminationandaretemporallylocated.

Signs

Critical.Oneormorediscretelightgraytoblackvitreousopacities,

oneoftenintheshapeofaring("Weissring")orbrokenring,suspended

overtheopticdisc.SeeFigure11.1.1.

Other.Retinalbreak,retinaldetachment,orvitreoushemorrhagemay

occurwithorwithoutaposteriorvitreousdetachment(PVD),withsimilar

symptoms.Peripheralretinalanddiscmarginhemorrhages,pigmentedcells

intheanteriorvitreous[releasedretinalpigmentepithelium(RPE)cells

or“tobaccodust”].

Figure11.1.1.PosteriorvitreousdetachmentwithoutWeissring.

Note

Approximately8%to10%ofallpatientswithacutesymptomaticPVDhave

aretinalbreak.Thepresenceofpigmentedcellsintheanteriorvitreous

orvitreoushemorrhageinassociationwithanacutePVDindicatesahigh

probabilityofacoexistingretinalbreak(>70%).See11.2,RetinalBreak.

DifferentialDiagnosis

•Vitritis:ItmaybedifficulttodistinguishPVDwithanterior

vitreouspigmentedcellsfrominflammatorycells.Invitritis,

vitreouscellsmaybefoundinboththeposteriorandanterior

vitreous,theconditionmaybebilateral,andthecellsarenot

typicallypigmented.See12.3,PosteriorUveitis.

•Migraine:Multicoloredphotopsiasinazig-zagpatternthat

obstructvision,lastapproximately20minutes.Aheadachemayor

maynotfollow.Normalfundusexamination.See10.27,Migraine.

Work-Up

•History:Distinguishretinalphotopsiasfromthevisualdistortion

ofmigraine,whichmaybeaccompaniedbynewfloaters.Durationof

thesymptoms?Riskfactorsforretinalbreak(previousintraocular

surgery,highmyopia,familyhistoryofretinaltearsand/or

detachments,darkcurtaininvision)?

P.275

•Completeocularexamination,includingexaminationoftheanterior

vitreousforpigmentedcellsandadilatedretinalexaminationwith

indirectophthalmoscopyandscleraldepressiontoruleouta

retinalbreakanddetachment.

•VisualizethePVDattheslitlampwitha60-or90-diopterlens

byidentifyingagray-to-blackstrandsuspendedinthevitreous.

Ifnotvisible,havethepatientlookup,down,andthenstraight

tofloatthePVDintoview.

•Ifavitreoushemorrhageobscuresvisualizationoftheretina,

u11rasonography(US)isindicatedtoidentifythePVDandruleout

aretinaldetachment(RD),tumor,orhemorrhagicmacular

degeneration.Occasionally,theflapofatearcanbeidentified.

See11.13,VitreousHemorrhage.

Treatment

NotreatmentisindicatedforPVD.Ifanacuteretinalbreakisfound,

see11.2,RetinalBreak.

Note

Aretinalbreaksurroundedbypigmentisoldandusuallydoesnotrequire

treatment.

Follow-Up

•ThepatientshouldbegivenalistofRDsymptoms(anincreasein

floatersorflashinglights,ortheappearanceofapersistent

curtainorshadowanywhereinthefieldofvision)andtoldtoreturn

immediatelyifthesesymptomsdevelop.

•Ifnoretinalbreakorhemorrhageisfound,thepatientshouldbe

scheduledforrepeatedexaminationwithscleraldepressionin2to

4weeks,2to3months,and6monthsafterthesymptomsfirst

develop.

•Ifnoretinalbreakisfound,butmildvitreoushemorrhageor

peripheralpunctateretinalhemorrhagesarepresent,repeated

examinationsareperformed1to2weeks,4weeks,3months,and6

monthsaftertheevent.

•Ifnoretinalbreakisfoundbutsignificantvitreoushemorrhage

oranteriorpigmentedvitreouscellsarepresent,repeat

examinationshouldbeperformedthenextdaybyaretinaspecialist

becauseofthehighlikelihoodofaretinalbreak.

11.2RetinalBreak

RetinalBreak

Symptoms

Acuteretinalbreak:Flashesoflight,floaters("cobwebs”or“spots”

thatchangepositionwitheyemovement),andsometimesblurredvision.

CanbeidenticaltosymptomsassociatedwithPVD.

Chronicretinalbreaksoratrophicretinalholes:Usuallyasymptomatic.

Signs

(SeeFigure11.2.1.)

Critical.Afull-thicknessretinaldefect,usuallyseenintheperiphery.

Other.Acuteretinalbreak:Pigmentedcellsintheanteriorvitreous,

vitreoushemorrhage,PVD,retinalflap,subretinalfluid,oranoperculum

(afree-floatingpieceofretina)suspendedinthevitreouscavityabove

theretinalhole.

Chronicretinalbreak:Asurroundingringofpigmentation,ademarcation

linebetweenattachedanddetachedretina,andsigns(butnosymptoms)

ofanacuteretinalbreak.

PredisposingConditions

Latticedegeneration,highmyopia,aphakia,pseudophakia,age-related

retinoschisis,vitreoretinaltufts,meridionalfolds,historyof

previousretinalbreakordetachmentinthefelloweye,trauma.

DifferentialDiagnosis

•Meridionalfold:Smallradialfoldofretinaperpendiculartothe

oraserrataandoverlyinganoraltooth;mayhavesmallretinalhole

atthebase.

•Meridionalcomplex:Meridionalfoldthatextendstoaciliary

process.

•Vitreoretinaltuft:Focalareaofvitreoustractioncausing

elevationoftheretina.

P.276

Figure11.2.1.Giantretinaltear.

•Pavingstonedegeneration.

•Latticedegeneration.

Work-Up

Completeocularexaminationwithaslit-lampandindirectophthalmoscopy

ofbotheyeswithscleraldepression.Scleraldepressionisdeferreduntil

2to4weeksafteratraumatichyphemaormicrohyphema.

Treatment

Ingeneral,lasertherapyorcryotherapyisrequiredwithin24to72hours

foracuteretinalbreaks,andonlyrarelyforchronicbreaks.Eachcase

mustbeindividualized;however,wefollowthesegeneralguidelines:

•Treatmentrecommended

o-Acutesymptomaticbreak(e.g.,ahorseshoeoroperculated

tear).

o一Acutetraumaticbreak(includingadialysis).

•Treatmenttobeconsidered

o一Asymptomaticretinalbreakthatislarge(e.g.,>1.5mm)

orabovethehorizontalmeridianorboth,particularlyif

thereisnoPVD.

o一Asymptomaticretinalbreakinanaphakicorpseudophakic

eye,aneyeinwhichtheinvolvedorthecontralateraleye

hashadanRD,orinahighlymyopiceye.

Follow-Up

•Patientswithpredisposingconditionsorretinalbreaksthatdonot

requiretreatmentarefollowedevery6to12months.

•Patientstreatedforaretinalbreakarereexaminedin1week,1

month,3months,andthenevery6to12months.

•RDsymptoms(anincreaseinfloatersorflashinglightsorthe

appearanceofacurtain,shadow,orbubbleanywhereinthefield

ofvision)areexplainedandpatientsaretoldtoreturnimmediately

ifthesesymptomsdevelop.

11.3RetinalDetachment

Therearethreedistincttypesofretinaldetachment(RD).Allthreeforms

showanelevationoftheretina.

RhegmatogenousRetinalDetachment

Symptoms

Flashesoflight,floaters,acurtainorshadowmovingoverthefieldof

vision,peripheralorcentralvisualloss,orboth.

Signs

(SeeFigures11.3.1,11.3.2,and11.3.3.)

Critical.ElevationoftheretinafromtheRPEbyfluidinthesubretinal

spaceduetoanaccompanyingfull-thicknessretinalbreakorbreaks.See

11.2,RetinalBreak.

Other.Anteriorvitreouspigmentedcells,vitreoushemorrhage,PVD,

usuallylowerIOPintheaffectedeye,nonshiftingclearsubretinalfluid,

sometimesfixedretinalfolds.The

P.277

detachedretinaisoftencorrugatedandpartiallyopaqueinappearance.

AmildRAPDmaybepresent.

Figure11.3.1.Rhegamatogenousretinaldetachment.

Note

Achronicrhegmatogenousretinaldetachment(RRD)oftenshowsapigmented

demarcationlineattheposteriorextentoftheRD,intraretinalcysts,

fixedfolds,orwhitedotsunderneaththeretina(subretinalprecipitates)

oracombinationofthese.Itshouldbedifferentiatedfromretinoschisis,

whichproducesanabsolutevisualfielddefect.

Figure11.3.2.Retinaldetachmentwithretinalbreakinlattice

degeneration.

Figure11.3.3.B-scanUSofretinaldetachment.

Etiology

Aretinalbreakallowsfluidtomovethroughtheholeandseparatethe

overlyingretinafromtheRPE.

Work-Up

•Indirectophthalmoscopywithscleraldepression.Slit-lamp

examinationwithcontactlensmayhelpinfindingsmallbreaks.

•B-scanUSmaybehelpfulifmediaopacitiesarepresent.

ExudativeRetinalDetachment

Symptoms

Minimaltoseverevisuallossoravisualfielddefect;visualchanges

mayvarywithchangesinheadposition.

Signs

Critical.Serouselevationoftheretinawithshiftingsubretinalfluid.

Theareaofdetachedretinachangeswhenthepatientchangesposition:

Whilesitting,thesubretinalfluidaccumulatesinferiorly,detachingthe

inferiorretina;whileinthesupineposition,thefluidaccumulatesin

theposteriorpole,detachingthemacula.Thereisnoretinalbreak;fluid

accumulationis

P.278

duetobreakdownofthenormalinnerorouterblood-retinalbarrier.The

detachmentdoesnotextendtotheoraserrata.

Other.Thedetachedretinaissmoothandmaybecomequitebullous.Amild

RAPDmaybepresent.

Etiology

•Neoplastic:Choroidalmalignantmelanoma(MM),metastasis,

choroidalhemangioma,multiplemyeloma,capillaryretinal

hemangioma,etc.

•Inflammatorydisease:Vogt-Koyanagi-Harada(VKH)syndrome,

posteriorscleritis,sympatheticophthalmia,otherchronic

inflammatoryprocesses.

•Congenitalabnormalities:Opticpit,morning-glorysyndrome,and

choroidalcoloboma(althoughtheseusuallyhavearetinalbreak).

•Vascular:Coatsdisease,malignanthypertension,andpreeclampsia.

•Nanophthalmos:Smalleyeswithasmallcorneaandashallowanterior

chamberbutalargelensandathicksclera.

•Idiopathiccentralserouschorioretinopathy(CSCR):Maybeseen

withbullousRDfrommultiple,largeRPEdetachments.See11.15,

CentralSerousChorioretinopathy.

•Uvealeffusionsyndrome:Bilateraldetachmentsoftheperipheral

choroid,ciliarybody,andretina;leopard-spotRPEchanges(when

retinaisreattached);cellsinthevitreous;dilatedepiscleral

vessels.

Work-Up

•Intravenousfluoresceinangiography(IVFA)mayshowsourceof

subretinalfluid.

•B-scanUSmayhelpdelineatetheunderlyingcause.

TractionalRetinalDetachment

Symptoms

Visuallossorvisualfielddefect;maybeasymptomatic.

Signs

Critical.Thedetachedretinaappearsconcavewithasmoothsurface;

cellularandvitreousmembranesexertingtractionontheretinaare

present;retinalstriaeextendingfromtheseareasmayalsobeseen.

DetachmentmaybecomeaconvexRRDifatractionalretinalteardevelops.

Other.Theretinaisimmobile,andthedetachmentrarelyextendstothe

oraserrata.AmildRAPDmaybepresent.

Etiology

Fibrocellularbandsinthevitreous(e.g.,resultingfromproliferative

diabeticretinopathy,sicklecellretinopathy,retinopathyof

prematurity,familialexudativevitreoretinopathy(FEVR),toxocariasis,

trauma,previousgiantretinaltear)contractanddetachtheretina.

Work-Up

•Indirectophthalmoscopywithscleraldepression.Slit-lamp

examinationwithcontactlensmayhelpinfindingsmallbreaks.

•B-scanUSmaybehelpfulifmediaopacitiesarepresent.

DifferentialDiagnosisForAllThreeTypesofRetinalDetachment

•Acquired/age-relateddegenerativeretinoschisis:Commonly

bilateral,usuallyinferotemporal,nopigmentedcellsor

hemorrhagearepresentinthevitreous,theretinalvesselsinthe

innerretinallayersareoftensheathedperipherally,white

“snowflakes”areoftenseenontheinnerretinallayers.See11.4,

Retinoschisis.

•X-linkedretinoschisis:Petaloidfovealchangesarepresentover

90%ofthetime.Dehiscencesoccurinthenervefiberlayer50%of

thetime.See11.4,Retinoschisis.

•Choroidaldetachment:Orange-brown,moresolidinappearancethan

anRD,oftenextends360degrees.Hypotonyisusuallypresent.See

11.27,ChoroidalEffusion/Detachment.

P.279

Treatment

•PatientswithanacuteRRDthatthreatensthefoveashouldbeplaced

onbedrestuntilsurgicalrepairisperformedurgently.Surgical

optionsincludelaserphotocoagulation,cryotherapy,pneumatic

retinopexy,vitrectomy,andscleralbuckle.

•AllRRDsthatdonotthreatenfixationoraremacula-off,or

tractionalretinaldetachments(TRDs)thatinvolvethemaculaare

repairedpreferablywithinafewdays.Visualoutcomesfor

macula-offdetachmentsdonotchangeifsurgeryisperformedwithin

10daysoftheonset.

•ChronicRDsaretreatedwithin1week.

•Forexudativeretinaldetachment,successfultreatmentofthe

underlyingconditionoftenleadstoresolutionofthedetachment.

Follow-Up

PatientstreatedforRDarereexaminedat1day,1week,2weeks,1month,

2to3months,thenevery6to12months.

11.4Retinoschisis

Retinoschisis,asplittingoftheretina,occursinX_1inked(juvenile)

andage-relateddegenerativeforms.

X-Linked(Juvenile)Retinoschisis

Symptoms

Decreasedvisionduetovitreoushemorrhage(25%)andmacularchanges,

orasymptomatic.Theconditioniscongenital,butmaynotbedetectedat

birthifanexaminationisnotperformed.Afamilyhistorymayormaynot

beelicited(X-linkedrecessive).

Signs

(SeeFigure11.4.1.)

Critical.Fovealschisisseenasstellatemaculopathy:Cystoidfoveal

changeswithretinalfoldsthatradiatefromthecenterofthefoveal

configuration(petaloidpattern).Unlikethecystsofcystoidmacular

edema(CME),theydonotstainorleakonintravenousfluorescein

angiography(IVFA),butcanbeseenwithindocyaninegreen(ICG).The

macularappearancechangesinadulthood.

Other.Separationofthenervefiberlayerfromtheouterretinallayers

intheretinalperiphery(bilaterallyintheinferotemporalquadrant,

mostcommonly)withthedevelopmentofnervefiberlayerbreaks;this

peripheralretinoschisisoccursin50%ofpatients.However,schisismay

occurbetweenanytworetinallayers.RD,vitreoushemorrhage,and

pigmentarychangesalsomayoccur.Pigmenteddemarcationlinesmaybeseen

eventhoughtheretinaisnotdetachedatthetime,unlikeacquired

age-relateddegenerativeretinoschisis.

DifferentialDiagnosis

•Age-relateddegenerativeretinoschisis(seethefollowing).

•RRD:Usuallyunilateralandacquiredandassociatedwitharetinal

tear.Pigmentinthe

P.280

anteriorvitreousisseen.See11.3,RetinalDetachment.

Figure11.4.1.Retinoschisis.

Work-Up

•Familyhistory.

•Dilatedretinalexaminationwithscleraldepressiontoruleouta

retinalbreakordetachment.

•Opticalcoherencetomography(OCT)canhelpdeterminethelayerof

theschisis.

Treatment

•Notreatmentforstellatemaculopathy.

•Forunresolvedvitreoushemorrhage,considervitrectomy.

•SurgicalrepairofanRDshouldbeperformed.

•Superimposedamblyopiashouldalwaysbeconsideredinchildren

youngerthan9to11yearswhenoneeyeismoreseverelyaffected,

andatrialofpatchingshouldbeconsidered.See8.7,Amblyopia.

Follow-Up

Every6months;sooneriftreatingamblyopia.

Age-RelatedDegenerativeRetinoschisis

Symptoms

Usuallyasymptomatic,mayhavedecreasedvision.

Signs

Critical.Theschisiscavityisdome-shapedwithasmoothsurfaceandis

usuallylocatedtemporally,especiallyinferotemporal1y.Usually

bilateralandmayshowsheathingofretinalvesselsand“snowflakes”

or“frosting”(persistentMuellerfibers)ontheelevatedinnerwall

oftheschisiscavity.UnlikeX-1inkedjuvenileretinoschisis,splitting

usuallyoccursattheleveloftheouterplexiformlayer.Theareaof

schisisisnotmobile,andthereisnoassociatedRPEpigmentation.

Other.Prominentcystoiddegenerationneartheoraserrata,anabsolute

scotomacorrespondingtotheareaofschisis,hyperopiaiscommon,no

pigmentcellsorhemorrhageinthevitreous,andabsenceofademarcation

line.ARRDmayoccasionallydevelop.

DifferentialDiagnosis

•RRD:Surfaceiscorrugatedinappearanceandcanbeseentomove

morewitheyemovements.Along-standingRDmayresemble

retinoschisis,butintraretinalcysts,demarcationlinesbetween

attachedanddetachedretina,andwhiteretroretinaldotsmaybe

seen.Onlyrelativescotoma.See11.3,RetinalDetachment.

•X-linkedjuvenileretinoschisis(seeprevious).

Work-Up

•Slit-lampevaluationforanteriorchamberinflammationand

pigmentedanteriorvitreouscells;neithershouldbepresentin

isolatedretinoschisis.

•Dilatedretinalexaminationwithscleraldepressiontoruleouta

concomitantRDoranouterlayerretinalhole,whichmayleadto

anRD.

•Afunduscontactlensevaluationoftheretinaasneededtoaidin

recognizingouterlayerretinalbreaks.

•OCTcanhelpdeterminewhichlayeroftheretinaissplit.

Treatment

•SurgeryisindicatedwhenaclinicallysignificantRDdevelops.

•AsmallRDwalledoffbyademarcationlineisusuallynottreated.

Thismaytaketheformofpigmentationattheposteriorborderof

outerlayerbreaks.

Follow-Up

Every6months.RDsymptoms(anincreaseinfloatersorflashinglights

ortheappearanceofacurtainorshadowanywhereinthefieldofvision)

areexplainedtoallpatients,andpatientsaretoldtoreturnimmediately

ifthesesymptomsdevelop.

P.281

11.5Cotton-WoolSpot

Cotton-WoolSpot

Symptoms

Visualacuityusuallynormal.Oftenasymptomatic.

Signs

(SeeFigure11.5.1.)

Critical.Whiteninginthesuperficialretinalnervefiberlayer(NFL).

Note

Thepresenceofasinglecotton-woolspot(CWS)inapatientthatdoes

nothavediabetesmellitus,acutehypertension,oracentralretinalvein

occlusion(CRVO)/branchretinalveinocclusion(BRVO)meritsawork-up

foranunderlyingsystemiccondition.

DifferentialDiagnosis

•Retinalwhiteningsecondarytoneuroretinitis,suchasthatseen

intoxoplasmosis,HSV,VZV,andcytomegalovirus(CMV).These

entitiestypicallyhavevitritisandretinalhemorrhages

associatedwiththem.See12.5,Toxoplasmosis,and12.8,Acute

RetinalNecrosis.

•Myelinatednervefiberlayer:Developspostnatally.Usually

peripapillarybutmaybeinretinalareasremotefromthedisc.

Figure11.5.1.Cotton-woolspot.

Etiology

Thoughttobeanacuteobstructionofaprecapillaryretinalarteriole

causingblockageofaxoplasmicflowandbuildupofaxoplasmicdebrisin

NFL.

•Diabetesmellitus:Mostcommoncause.Oftenassociatedwith

microaneurysms,dot-blothemorrhages,andhardexudates.See

Section11.12,DiabeticRetinopathy.

•Chronicoracutehypertension(HTN):Mayseeretinalarteriolar

narrowingandflamehemorrhagesinchronicHTN.AcuteHTNmayhave

hardexudates,opticnerveswelling,exudativeretinaldetachment.

SeeSection11.10,HypertensiveRetinopathy.

•CRVOorBRVO:Unilateral,multiplehemorrhages,venousdilation,

andtortuosity.MultipleCWS,usually>6to10,seeninischemic

varietyofCRVO/BRVO.See11.8,CentralRetinalVeinOcclusion,and

11.9,BranchRetinalVeinOcclusion.

•Retinalemboli:Oftenfromcarotidarteriesorheartwithresulting

ischemiaandsubsequentCWSdistaltoarterialocclusion.Patients

requirecarotidDopplerexaminationandechocardiography.See

10.22,TransientVisualLoss.

•Collagenvasculardisease:Systemiclupuserythematosis(most

common),Wegenergranulomatosis,polyarteritisnodosa,or

scleroderma.

•Giantcellarteritis(GCA):Age>55years.Symptomsincludevision

loss,scalptenderness,jawclaudication,proximalmuscleaches,

etc.See10.17,ArteriticIschemicOpticNeuropathy.

•HIVretinopathy:Singleormultiplecotton-woolspotsinthe

posteriorpole.See12.10,NoninfectiousRetinal

Microvasculopathy/HIVRetinopathy.

•Otherinfections:Toxoplasmosis,orbitalmucormycosis,Lyme,

leptospirosis,RockyMountainspottedfever,onchocerciasis,

subacutebacterialendocarditis.

P.282

•Hypercoagulablestate:Lupusanticoagulant,homocystinuria,

proteinCandSdeficiency,antithrombinIIIdeficiency.

•Radiationretinopathy:Followsradiationtherapytotheeyeor

periocularstructureswhentheeyeisirradiatedinadvertently.May

occuranytimeafterradiation,butoccursmostcommonlywithina

fewyears.Maintainahighsuspicioneveninpatientsinwhomthe

eyewasreportedlyshielded.Usually,3,000cGyisnecessary,but

ithasbeennotedtooccurwith1,500cGy.Resemblesdiabetic

retinopathy.

•Interferontherapy.

•Purtscherandpseudo-Purtscherretinopathy:MultipleCWSsand/or

superficialhemorrhagesinaperipapillaryconfigurationin

patientswithahistoryofsevereheadtraumaorcrushinjuryto

thechestorlowerextremities.Typicallybilateralbutcanbe

unilateralandasymmetric.See3.19,PurtscherRetinopathy.

•Cancer:Metastaticcarcinoma,leukemia,lymphoma.

•Others:Migraine,hypotension,intravenous(i.v.)druguse,

papilledema,papillitis,severeanemia,sicklecell,acuteblood

loss.

Work-Up

•History:Diabetesorhypertension?Ocularorperiocularradiation

inpast?GCAsymptomsincludingscalptenderness,jawclaudication,

etc.?Symptomsofcollagenvasculardiseaseincludingjointpain,

rashes,etc.?HIVriskfactors?

•Completeocularexamination,includingdilatedretinalexamination

withaslitlampanda60-or90-diopterlensandindirect

ophthalmoscopy.Lookforconcurrenthemorrhages,vascular

occlusion,vasculitis,hardexudates.

•Checkafastingbloodsugar.

•Checkbloodpressure.

•ConsiderESR,CRP,andplateletsifGCAissuspected.

•ConsidercarotidDopplerexaminationandechocardiog

温馨提示

  • 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
  • 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
  • 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
  • 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
  • 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
  • 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
  • 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

评论

0/150

提交评论