Simulationinophthalmology 窑Review窑 Malingeringorsimulationinophthalmology-visual acuity

1S.BKonyaEg姚itim-Ara tirmaHastanesiGzKlinig姚i, Konya, INTRODUCTION 鬤 觟 Turkey imulationcanbedefinedasintentionallycounterfeiting 2GATAG zKlinig姚i,Ankara,Turkey 觟 S a diseasewithbenefitinstinctlikeincaseof Correspondence to: AliIhsanIncesu.S.BKonya Egitim- malingering,ormisattributinghis/hersymptomstoanother Ara tirmaHastanesiG zKlinig姚i,Konya,Turkey.aiincesu@yahoo. 鬤 觟 irrelevantclinicalentitylikeincaseofexaggerating.Ifthe com subjectbelievesthathe/sheisreallyill,thenitiscalled Received:2011-01-20Accepted:2011-05-06 'conversionreaction'or'hysteria'.Incaseofconversion, subjectreallyliveshis/hersymptomsandcan'tcontrolor Abstract evenknowthattheyarepsychogenicinorigin [1-5]. Inall ·Simulationcanbedefinedasmalingering,orsometimes casesofrealsimulationornegativesimulationthereisonly functionalvisualloss(FVL).Itmanifestsaseithersimulating oneinstinct:Benefitmaybemonetaryornonmonetary.It anophthalmicdisease(positivesimulation),ordenialof maybesometimesescapeofmilitaryserviceorwork,get ophthalmicdisease(negativesimulation).Consciousbehavior reductionofcourtpenalty,getcompensationfromsocial andcompensationorindemnityclaimsareprominentfeatures securityagenciesorinsurancecompanies,getunnecessary ofsimulation.Sincesomeauthorssuggestthatthisisa freemedicinesormedicalequipments.Theaimisrarely manifestationofunderlyingpsychopathology,even attractionofsympathy,helpoffamilyorsocialenvironment. conversionisincludedinthiscontext.Intoday'sworld, Determiningrealincidenceorprevalenceofsimulationis everyophthalmologistcanfacewithsimulationofophthalmic difficult,becausemajorityofcasesisarenotreported. diseaseordisorder.Incaseofsimulationsuspect,the VillegasandIlsenreportedthat10%-30%ofoutpatient physician'sresponsibilityistoprovethesimulation consideringthedisease/disorderfirst,andsimulationasan populationofneurologyclinicshasnoorganicpathologyand exclusion.Insimulationexaminations,thephysicianshould 1/3tohalfofpopulationapplyingtoprimaryandsecondary [1] befirmandsmarttoselectappropriatetest(s)toconvince caresettingshavenopathologicallesions .Inastudyof17 notonlythesubject,butalsothejudgeincaseofindemnity casesofidiopathicintracranialhypertensionNey [2] orcompensationtrials.Almostallophthalmicsensoryand reportedthatallpatientsimitatedfunctionalvisualacuity motorfunctionsincludingvisualacuity,visualfield,color andfieldlossand88%alsopresentswithsignificant visionandnightvisioncanbethesubjectofsimulation. psychiatric,psychosocialorothermedicalcoexistent Examinermustbeskillfulinselectingthemostappropriate pathologies.Insomeresearchpapers,1-7%ofalleyeclinics test.Apartfromthoseintheliterature,weincludedallkinds outpatientpopulationisreportedassimulation [3,5].Someof ofsimulationinophthalmology.Inaddition,simulation thesepercentagesarereportedfromatertiaryuniversityor examinationtechniques,suchas,useofOCT(optical military referenceclinics;therefore,realincidenceor coherencetomography),frequencydoublingperimetry(FDP), prevalencehasnotyetbeendetermined.Moststrikingly, andmodifiedpolarizationtestswerealsoincluded.Inthis 13%ofallpsychiatryoutpatientcases,45%ofsocial review,wemadeathoroughliteraturesearch,andaddedour securitycompensationsorlegalclaimsarereportedas experiencestogivethereadersup-to-dateinformationon [1,4] malingeringorsimulationinophthalmology. simulation .AnarticleGandhiandAmulareportedthat59 billionUSDdollarswerepaidtosimulationcasesby ·KEYWORDS:malingering;simulation;conversion;hysteria insurancecompaniesin1995inUSA [5].VillegasandIlsen DOI:10.3980/j.issn.2222-3959.2011.05.19 reportedthat5-12%ofpatientspresentwithvisuallosstoa neuroophthalmologistarediagnosedasfunctionalvisualloss IncesuAI,Sobac G.Malingeringorsimulationinophthalmology- [1] 覦 (FVL) .Inclinicalexamination,ifthesubjectexpectsa visualacuity. 2011;4(5):558-566 monetarybenefitorifcomplaintsandexaminationfindings donotfitintoadiagnosisornotcoincidingtoeachother,

558 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 4熏晕燥援 5熏 Oct.18, 圆园11 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-83085628 耘皂葬蚤造押陨允韵援圆园园园岳员远猿援糟燥皂 thenclinicianmustsuspectthatitwouldbeasimulation andinnocentdiagnosisandfollowedcloselywithoutthe case [3,4,6-8]. subject'sawareness. Sobaci [3] andThompson [9] classifiedthoseproblematic CONVERSION casesintothreeclasses.Thefirstoneisintentional Conversiontermcomprisesdefinitionsofpsychogenic simulationcase,thesecond,hystericsthatareinnocentbut diseaseor'hysteria.Sometimesrealsimulationor opentoautosuggestions,andthethirdisthesubjects misdiagnosedconversioncaseswouldbeattributedto exaggeratingsymptoms.Understandingthepsychological hysteria.Ontheotherhandsimultaneouslyfunctionalvisual natureofvisuallossandsubjectivefindingsmaybe lossandorganicvisuallossoccurinthesamecaserarely relativelyeasy.Butlookingforcounterevidenceslikevisual andthosecasesarecalled"functionaloverlay" [11]. acuitytests,visualfieldanalyses,electrophysiologicaltests Functionaloverlayincidenceisreportedas16.7%oreven etc.provingsimulationisadifficulttask.Inthesecasesall 25-53% [6,12,13].Anconversionorhysteria,subjectdoesn't subjectiveandobjectivetestsshouldbeapplied.During imitateavisualpathologyintentionally.He.shedoesbelieve subjectivetestslikevisualacuity,contrastsensitivityand sincerelythathe/sheisillanddoesn'twanttocheat visualfieldtestssincerecooperationofsubjectisneeded. ophthalmologist.Afterapsychicshockhe/sheasadmittedto Butifthesubjectisuncooperativeandsaysthathe/shedoes emergencyclinic,ingeneral,withthediagnosisofsudden notseesatallorevenhe/shetriestofakeophthalmologist visualloss,sometimeswith visualfieldloss,diplopia, overtly,itishardtointerprettheexaminations.Inthese -pain, asthenia,dyschromatopsia,blepharospasmor casestheexaminationsandtestsarewidelyexpanded. ptosis [1].Thenhe/sheistransferredtoophthalmologyclinic Inthissituation,techniquesthatexaminelightsensation fromemergency.Subjectisgenerallyayoungpersonand (visuallyevokedpotentials(VEP), sincerelycooperatesinexamination.He/sheisverycalm, (ENG),electroretinography(ERG) ),visualacuity evensurprisinglyindifferentagainsthis/hergravecomplaints [1]. (optokineticnystagmus,patternVEP )andprobesretinal Afterexamilation,whenhe/sheistoldhe.sheishealthyand pathologyanditsburdenonvision(opticalcoherence hasnoprobleminhis/hereyes,he/sheadmitsdiagnosis tomography(OCT),ERG,fluoresceinangiography(FA)or easilyandcalmlythankstheophthalmologist.He/sheand indocyaninangiographyICG )areneeded.Complexand his/herrelativesneveroppose ophthalmologist [1]. diversifiedtestsandequipmentsmakesimulationmore Ophthalmologistoughttotalktosubjectsoftly,sayinghe/she difficultandriskyforthesubject.Itisannecessityfor is`healthy,his/hereyesarenormal,andsymptomswould clinicianstocategorisethecaseasapositivesimulationor disappearinfewdays.Ifthesubjectisaccompaniedwitha negativesimulation.Simulationcasesareguiltyand cleverandcooperative`adult,heisalsoinformedalone psychopathicbutbravecharactersandtheyareguidedonly aboutthesituationthatthesymptomsarepsychologicalin bybenefitinstinct [3,7,10].Toundercoverthesimulation originandsubjectperhapswillneedsupportofhis/her requiresaprecautions,fast,kind,skilledanddiscreet familyandfriends;thesubjectmayneedprofessional ophthalmologistandathoroughexamination. psychiatrichelpifthesymptomsdonotsubside.In Anotheraimofthispaperistoremindophthalmologists conversion,almostallsensorial(afferent)symptomsare FVLcasesarenotalwaysguidedbyeventssuchasearly seen.Motorsymptomsareveryrare [14].Insomeconversion retirement,immunitytomilitaryservice,salaryofdisabled, patientsthalamichypoactivityisreportedinPETscan) [1]. escapefromcourtpenaltylikebenefits;sometimesitwould Thisisinaccordwithfunctionaloverlaycases.Primarily beasimpleneurosismrconversioncase.Inthiscases visualacuity,thensometimesvisualfieldlosscomplaintsare withoutcomplextestsandexaminations,it'spossibleto reportedinconversioncases[1,11,16].Kathol [11] investigated makeadefinitediagnosiswithrelativelysimpleandeasy 54conversioncasescollected-overaperiodof24yearsand simulationexaminationtechniques.Simulation,ingeneral,is reportedthatthemostfrequentcomplaintwasvisualacuity metinmilitaryrecruitmentorearlyretirementordisabled loss.Then,isolatedvisualfieldlossandcombinedvisual salary,workortrafficaccidentsorcriminalfights acuityandfieldlossarereportedrespectively.Examination examinations.Inthesecases,subjectsometimescomeswith performedyearslaterreportedthatvisualacuityimprovedin simplechangesorverylittlepathologyinpalpebrae, 51to78%ofcases.Only22%ofcasesreporteddisabling conjunctiva,corneaorpupilsandattemptstointentional visualacuitylossyearslater.Again,visualprognosisis exaggerationorsimulation.Itisadvisablethat good,especiallyinyoungpeople [1,11,16].Visualacuity ophthalmologistshouldbeexperienced insimulation improvesinauncertaintimespantotalorpartially [1]. Visual examinationsandhassufficientequipment.Ifnoalternative acuityisgenerallybetween1/10to5/10range.Whenvisual existssubjectshouldbehospitalizedinventinganirrelevant fieldlossisreported,it'sgrossconcentricnarrowing(tubular 559 Simulationinophthalmology vision) [11,17].Inthesecases,generallypsychiatrichelpisnot helpstoexaminer [19].Incontrast,itmaycausefuture necessaryatthetimeofdiagnosis.Suggestion,patienceand administrativeorevenlegalproblems. reassurancehelpophthalmologisttorelieveconversioncase SchutzandMavrakanasintheirstudyof172casesof atfirsthand.Sometimesorganicbrainsyndromesmimic malingering,exaggerationormisattributingreportedthatthe conversionsyndrome.Eliminatingorganicbrainsyndrome mostfrequentexaggeratedormisinterpretedcomplaintsare requireslookingforlateralizationof findings,motor 74%visualacuityloss,28%discomfortfeeling,19%visual neurologicdeficitsandsometimesneurologyconsultation [15]. fieldloss,17%headacheand13%photophobia.Visual SIMULATIONORMALINGERING acuityandfieldloss,discomfort,headacheandepiphoraare Malingererdoeseverythingtocheatophthalmologist.In mostlysimulatedsymptoms.Medicalrecordsofcasesabout generalhe/sheistransferredfromcourt,localmilitarydraft pastmedicalhistorygaveusefulinformationin163of172 office,healthinsuranceorothergovernmentalorganizations. casesindiagnosisoffunctionalloss[20].Besideofconversion He/sheisveryattentivetodoctor'sattitudestounderstand andmalingering,somecaseswhoinflictedtemporaryor thenatureofexaminationsandhideshis/hersimulation longstandinginjuriesontheireyesarereported.Thosecases instinct.Thosetransferandattitudedifferencesareeven arecalledMunchausenSyndromeandoutofthescopeof sufficienttodistinguishsimulationfromconversion.They thispaper.It'sakindofselfinjury(passiveaggression)and seriouslychallengeiftoldhe/sheissimulating,become metgenerallyinyoungpeopleexperiencingpsychological furiousandmayevenassaultthephysician [14].Theyget problemswiththeirfamily,schoolandwork[21]. angryespeciallyteststakelongtime [4].Althoughatfirst,it's SIMULATIONOFVISUALACUITYLOSS logicalforophthalmologisttothinkcautiouslythatsubject SimulationofBilateralAmaurosis Fiftytoeightypercent wouldbereallyill. offunctionallosscomplaintsarebilateral [5].Butsimulation Someoftheimportantpointstoberememberedindoubtful ofbilateralamaurosiswithoutgettingcaughtisdifficult. casesare: Therefore,itismetingenerallyinconversioncasesrather (1)Nevergiveimpressionthatyoususpectsimulation.This thanmalingerers [22].Asinallfunctionallossexaminations, leadsthesubjecttobemuchmoreattentiveandcautious. thefirstthingtodoisvisualacuityexamination.Ifthe Performexaminationcalm,fastandasifadaily,routine subjectentersandwalksaroundtheexaminationroomeasily work. withoutanyhesitationit'sanindicationforovertsimulation. (2)Dowriteallcomplaintsandmanifestationsincluding Belowarethemostusefulclinicaltestsforbilateral contradictoryoneswithsubject'sownwordswithall amaurosissimulationexamination. symptoms,beginningtime,moodwhenenteringtheroom, SubjectiveTestsforBilateralAmaurosis typeofsitting,psychologicalprofileandreactions.Those Eyecontact Eyecontactmaybeanimportantindicator recordswouldbenecessaryincaseoffuturejudicial discriminatingsimulationfromorganicdisease.Ifasubject investigations. claimsthathe/sheistotallybilateralblindandgetscaught (3)Doaserious,detailedandfastexamination;writethe witheyecontactwithexaminers,itisdefinitelyacaseof testsandresultswithdetails.Alwaysfirstobtainbilateral simulation [1]. bestcorrectedvisualacuitywithobjectiveandsubjective Roomwithobstaclestest Roomwithobstaclestestcould tests [3,18].Routinerefractionexaminationmaynotbe beperformedasafirstchoice [3,4,23].Wastebasket,chairsetc sufficientandperformseveraltechniquesofrefraction areplacedinthemiddleofexaminationroombefore examination. subject'sentry.Inthisenvironment,itisnoticeablethat (4)Donotletanyfriendorrelativeofsubjectstayin simulating subject playsainteresting,artificialand examinationroom.It'scrucial. constrainedroleofamaurosis.Arealblindwalksheadup, (5)Doperformtestsandexaminationsyouknowwellina butasimulatingpersonheaddownandupsetwithfearof fastandperfectwaywithoutlettingsubjectobserve,think gettingcaught,simulatingpersonsometimeswearsdark andadapttothetest [19].Dorememberthatsubjectwouldbe glassesandholdsawhiteblindwalkcane.Wearingdark aclever,foxy,attentiveandprobablyasimulatingcase. sunglassesallthetimeisasignofsimulation [24].Simulators (6)Dohaveatleastoneattentiveprofessionalperson,a hitobstaclesintheroomintentionallyandhurtthemselves, doctorifpossible,asaneyewitnesswithyouduring walkinattentively,evenrefuseswalkintheroomwithoutthe examination asaprecautionagainstfuturejudicial helpofothers [25,26].Realblindpeoplearecalm,walkinthe investigationsagainstyouoryourinstitutions [13]. roomcalmlyandattentivelyexaminingtheirfront,sensing (7)Managementofsimulationormalingeringcasesneeds theobstaclesandwalkperipheral.Conversioncasescan understandingandpositiveapproach.Confrontationnever easilywalkaroundofobstacleswithouthitting [3,4,22,23]. 560 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 4熏晕燥援 5熏 Oct.18, 圆园11 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-83085628 耘皂葬蚤造押陨允韵援圆园园园岳员远猿援糟燥皂 Lookathand (Schmidt-Rimpler)test [3,4].Subjectistoldto Pupillaryexamination Pupillaryexaminationisanother lookathis/herhand.Realblindextendshis/herhand,looks usefuldiscriminationtest.Presenceofbilateraldirectand atitandsays"Iknowwheremyhandisbutcannotseeit". indirectlightreflexesshowsthatinferiorvisualpathwaysare Simulatingsubjectextendshis/herhandtoandfrobutdoes intact,andatleastlightperceptionandprojectionispresent. notlookatitandsaysshortcut"Icannotseeit" [4]. Veryrare But,eveninthepresenceoflightreflexes,corticalor casesofcorporealagnosiacannotperformthistesttoo. subcorticalblindnesscan'tberuledout [3]. Ontheotherhand Signaturetest[4] Whenthesubjectisgivenapenandpaper incasesoffunctionalloss,secondarymyosisormydriasis andaskedtosign,simulatingcasescribbles.Realblind mightbeobserved.Simulatorcouldexploitmyoticor easilyandregularlysignsmultipletimes [3,4]. mydriaticdrops [5].Ifsubjectisreallybilaterallyamaurotic, Menace test Whensubjectsittinginhis/herchair theyshouldhavealsobilateralfixeddilatedpupilsandno comfortably,examinerpasseshis/herhandcloseinfrontof responsetolight.Onlyexceptionisbilateraloculomotor subject'seyesuddenly.Ifthesubjectcloseshiseyes,it paralysis.Inthiscaseptosisandesotropiaarenoted. meansthathe/shesees.Evenifsimulatordoexercisesbefore Headrotationtest Headofsubjectcanberotatedfast toholdhimselfduringthetesthe/shecan'tstoptachycardia about30degreesinoppositedirectionsandifnystagmus occurringduringthetest [3,4,17].Againexaminercansuddenly occursitmeansthatthecasecouldn'tseeatall.Ifno makeahandmovementwithshamefulandsexualmeanings nystagmusispresent,atleastonefixationmechanismand towardsthesubject,ifthesubjectlaughsorsmilesitmeans indirectlysomedegreeofvisionispresent [4]. thathe/shecouldseeit [3]. Ifchangesinbasaloccipital Mirrortest It'sararelyapplied,butusefultestincasesof rhythmrecordingsareobservedwhenlightisprojectedto bilateralamaurosisordeepamblyopia.[3-5].Amobilefullsize ,itindicatesthereisatleastslightvisualactivity [4]. mirrorisplacedinfrontofthesubject,andhe/sheistoldto Pattern visually evoked potentials Patternvisually lookatitbotheyesopen.Whenmovingthemirrorslightly evokedpotentialsiswell-knownmethodforevaluationof toandfroexaminerlooksatthesubject'seyessecretly.Ifthe afferentvisualpathwaydysfunctionsincludingthemacula subjectlooksathimselfinthemirror,itmeanshe/shecan andtheopticnerve.Incaseofunilateralamblyopiaor see.Inunilateralamblyopia,soundeyeisclosedandsubject blindness, asymmetrical recordingsoftwoeyesare isobservedsecretlywhilehe/shelooksintothemirror. expected.PVEP caneasilydiscriminateexistenceof Fingertonosetest Fingertonosetesthasthesame unilateralblindnessbutmaynothelptoquantificationof physiologicalmechanismanddiagnosticvalueoffingerto visualacuitybetween2/10andfullvision,10/10.Normal fingertestbelow [1].Subjectisaskedtotouchhis/herindex PVEPandERGisnotcompatiblewithvisualacuityless fingertonosewheneyesareclosed.Simulator,againplaysa than6/10 [14].Ontheotherhand,patternVEPrecordings rolethathe/shetriesbutcan'tdoit. using5differentpatternsizeshasbeenshowntoquantifythe Indexfingerorproprioceptiontest[4,5,14] Subjectistoldto visualacuitylevelandpatternVEPiswellcorrelatedwith holdhis/herarmsupinshouldersandhandsopentosides visualacuitylevelswithsensitivity97%andspecificity whenhis/hereyesshut.He/sheistoldtoputhis/herindex 62%[3,38]. fingersend-to-endinthefront.Realblindcandothatdueto HOSPITALISATION deeplemniscalsensitivity.Malingererplaysrolehe/shetries Afterallthesetests,ifthediagnosisofmalingeringcannot butcan'tdoit.Onlycorporealagnosiscasescan'tperform beconfirmed,he/sheishospitalizedwithanirrelevantanda thistest [5]. fakediagnosisandfollowedcloselywithoutlettinghim/her ObjectiveTestsforBilateralAmaurosis notice.Nursesandclinicstaffareinformedandaskedto Optokineticnystagmustest Whilethesubjectislooking followsecretlydayandnight.Whenthesubjectforgets atBarany'scylinder,ifnystagmusappears,itmeanshe/she playinghis/herblindroleorfeelsthathe/sheissafe,he/she seesit [3-5].Itmeansatleast1/20or1/10Snellenlinevision [5,27]. mightdofreemovesthatindicateshe/sheisseeing [3,14]. Thistestneedsstrictlightingconditionsandstandard Anothertrickisthat,ifanappointmenttimeissetbeforeand Barany'scylinder.It'susefultodiagnoseinconversionand aphotoofsubjectisathand,preferablyonephysicianwould malingering [5]. watchsecretlywhilethesubjectcomestotheclinicfromthe Psychogalvanictest Subjectsitsinfrontofaslitlampand parkinglot.Ifthisprecautioncouldbeperformed,examiner suddenlyabrightlightreflectedonhissocalledweakeye.If andcliniccansavelotsofmoneyandtime.Againanother he/sheblinksorwateringoccurs,itmeansthathe/shesees solutionistofollowupthesubjectuponhis/herleavefrom thelight [3,4].Lightsweatingandvasomotorstimulationalso clinictothestreet. couldbeobservedandisinterpretedagainassimulation. Insomesuspiciouscases,examinermighthavetoperform 561 Simulationinophthalmology objectiveteststoeliminatearetinalblindingetiology.Ifa discordancebetweenanswersitisnecessarytorepeatthis pathologysecondarytoopticneuropathyisconsidered, examination [14] fundusexamination,swingingflashtest,directandindirect Snellentestinmirror Snellentestinmirrormaybe lightreflexes,VEPandsometimescomputedtomographyor performed.Six-meterofregularvisualacuityassessment magneticresonanceimaging(MRI)ofopticnervetractwith distancecouldbeeasilydoubledviamirrorandsubjectis contrastdyeare performed.Again,alltestsand madethinkhis/hervisualacuityirregularlyreduced.In examinationsperformedmustbeincludedinmedicalfiles reality,ifdistanceisdecreasedtoitshalfthenvisualacuity andthecomputerindetailasaprecautionforfuturelegal mustbedoubled.Differentresultsmeanmalingering.Visual investigations.Resultsoflaboratorytestsareadvisedtobe acuitytestcouldbeperformedfirstfrom6metersthen3 gluedorstapledtofile.Allfilesmustberecordedatthe metersandresultscompared [4]. computerwithextraprotectivemeasuresagainstfile Reassurancetest Reassurancetestisalwaysamongthe smuggling. mostusefuloptions.Ophthalmologistbeginsexamination Toruleoutcorticalblindness,coincidentsymptomsand firstshowof20/10optotypesandwhenthecasecan'tsee, signslikedisorientation,confusion,epilepticattacksand thenembarrassedexaminershows20/15optotypes.Andif otherneurologicaldeficitshavetobesearchedinmedical thesubjectsayshe/shealsodoesnotsee,examinerexpresses historyandexamination.Inrealcorticalblindness,pupillary extremewonderandsayshecannotbelievethatthesubject reflexes,fundusexaminationandoculomotortestsshouldbe couldnotsee20/15optotypesandinsiststhatthesubject normal.SubjectasinAntonSyndromemightbeunawareof mustseeatleast10/10optotypes [3].Evensays"theletters his/herblindness.He/shehasnopalpebralmenacereflexes. nowaredoublesizeofformer" [27].Examinationcouldbe Bilaterally,heseesnothingormaximumlikeviewingfrom repeatedwithreadingchartsofdifferentoptotypes. apipe.VEPabnormalityisevident.Insuspiciouscases, Lyttontest Lyttontestmaybeperformed.Beforeofweak neurologyconsultationisaskedafterinformingthe eye+1.0Din90degreesand-1.0Din45degreesglasses neurologistaboutthecase.Corticalblindnessisencountered placedandsoundeyeclosed.Subjectistoldtofindthe ingeneralwithinfarctsorveryrarelytumorsplacedin brightestview.Anhonestsubjectneutralizestwoglassesin bilateraloccipitallobes.Hemorrhagesarenotexpected. 90or45degreesandreadshonestly.Simulatordoesn't Sometimescoup-countercoupheadtrauma,deepuremia, neutralizethelensesproperlyandreadsmaximumhalfof postpartumamnionembolism,postcoronaryangiography his/herrealvision [4]. spasm,incontinentiapigmenti,orsimilartoxicreasonsmay Baudrytest Examinerwantsthesubjecttoreadnearchart. beresponsible [1,28].Ifcorticalblindnessisduetotraumano He/shewillsaythathe/shecan'tread.Thenexaminerplaces MRIsignscouldbeseenatfirst.Visualfielddefectsleanto +6.0Dintrialsetandasksthesubjecttoreadnearchartin verticalmeridianandit'susefulindifferentiationfrom tipofnoseandthensaysthatthepowerofglasseswillbe simulationincaseofpipevision [24,28]. doubled.Incontrast,examinerplaces-6.0Dglassesandat SimulationofBilateralAmblyopia It'sfrequentlymetand thesametimedrawsnearcharttoreaddistance.Ifthe easilymimickedtypeofsimulation.Sixty-fivepercentof subjectsimulates,he/shecaneasilyreadthechart,then visualfunctionallosscaseshavebilateralamblyopia [29]. his/herrealvisionismeasured [4]. Bothsubjectiveandobjectiveexaminationtechniquescanbe Statisticalcalculations Statisticalcalculationsisanewtest usedforthispurpose. developedforvisualacuityorfieldevaluation.Forvisual SubjectiveExaminationTechniquesforSimulationof acuityevaluation,atleast16optotypesdesignedforevery BilateralAmblyopia Snellenlineinmixedstyleisshowedtothesubjectat Specialoptotypes Specialoptotypesisoneofclassical random.Correctanswerstopresetnnumberoptotypeswith examinationsofsimulationandprobablytheeasiest. correctanswersofthesubjectcomparedandcalculated Optotypesareprintedonthesamesizecartoonsandhave accordingtodispersionfunctionofbinomialformulaof identicalsizesandpresentedtothesubjectunder everySnellenline.Pvaluesof 0.01indicatesthatanswers 臆 standardizedlightingconditions.Therearelotsofcartoons areintentionallywrong.LandoltCoptotypeson32white thathavethesameordifferentvisualequivalents.Optotypes' platesareprojectedfor2secondsandanswersarerecorded. numberandleglengthsandtotalsurfacefieldsaredifferent. Correctanswersrateiscomparedtodispersionofbinomial Thedistancesofspacesbetweenoptotypesandtheirlengths formulawhichcouldprovidethisratebypurechance. aresamebutvisualequivalentsaredifferent.Simulating Accordingtoareport,74%of20voluntarypseudosimulators personcannotknowthatbigsizeoptotypesmayhavethe and80%of15realsimulatorscouldbedetermined [30]. samevisual equivalentwithsmallones.To correct Thesetestareveryusefulindeliberateuncooperative 562 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 4熏晕燥援 5熏 Oct.18, 圆园11 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-83085628 耘皂葬蚤造押陨允韵援圆园园园岳员远猿援糟燥皂 malingerers.Thismethodcouldalsobeusedinvisualfield maycauselossofsubject'srights.Forexample,early simulations.Invisualfieldexamination,saccadicresponses Stargardt'sDisease,earlyonsetmaculardystrophy, oftheeyetostimulithatarecompletelyatrandomprojected amblyopia,conedystrophy,atypicalretinitispigmentosa tofourquadrantsofeyeareobservedandresultsare (sinepigmento),keratoconus,centralserousretinopathy, calculated.Preferencesofsaccadestooppositedirectionsof retrobulbarneuritis,opticnervecompression,chiasmal projectedstimuliagainindicatessimulation [31]. tumors,hereditaryopticneuropathiesandcorticalblindness Stereoscopy Stereoscopycanbeusedforevaluationof couldbeconsideredinthiscontext. [4,5,22,29]. Inordernotto simulation.Thereseemstobedirectrelationbetweenvisual missoutatleastsomeofthesecases,it'simportanttopay acuityandstereoscopy [27].Subjectistoldthatit'sashort, attentiontopupillaryreactionsduringswingingflashtest.In fast,routineandsimpletest.ThenTitmustestisperformed. caseofsuspicion,someadvancedtestslikefluorescein Allfly,animalandcircleoptotypesseeingrequiresadefinite angiography,indocyaninegreenangiography,ERG,VEP, fullbinocularvisionlevel.Thatistosay,seeingofnine darkadaptation,cornealtopographycouldbeperformed. circlesmean40secondarcorfullbinocularvision [5].A Evenindetailedexamination,asreported2.2%ofthecases personthatclaimshandmoveandperforms52secondsarc whichdiagnosedasmalingeringhaveprovedtohavean stereoscopyshouldhaveinreality7/10Snellenvisionof underlyingorassociatedorganicpathology [29].Thereisno botheyes [27] oridentificationoffourofninecirclesneedsat doubtthatsomespecificproceduresmayenabletimely least2.5/10Snellenlinevision [25].Itisagoodmeasureof diagnosisofpathologiesmentionedabove.Mostfrequently visualacuity [4,12,17].Unfortunatelyattentivemalingerers encounteredofthesepathologiesaccountingforvisualacuity rapidlyrealizesthattestneedsbotheyesandcloserapidly decreaseinseeminglyhealthyeye. oneeye,soexaminermustbevigilantandcatchthis Amblyopia Inotherwisehealthyeyeswithnoremarkable maneuverofsubject. ocularsignexplainingvisualacuitydecreaseamblyopiais ObjectiveExaminationTechniquesforSimulationof thought.Amblyopiagenerallycanbediagnosedinpresence BilateralAmblyopia ofmorethan+1.0Dasymmetricalrefractiondifference. Optokineticnystagmus Itisidealfordeterminationof Visiononweakeyeisnobelowof1/10ingeneral.Agood grossvisualacuitywithoutcooperationofcase.Thistest history,open-closetest,streakretinoscopywetifnecessary requiresfixedlightningconditionsandBaranycylinderbut andcrowdingphenomenononfundoscopyareperformed resultsarenotalwaysdefinitive.Fromdistancewhich andanisometropiaislookedfor [22,32]. subjectclaimsthatcannotseeoptotypesBaranycylinderis Conedystrophy Bilateralbutasymmetricalandslowpace rotatedandifnystagmusturnsout,itmeanssimulatorcan visualacuityandcolorvisiondecreaseisnotedinchildren seeatleastfromthatdistanceandhe/sheislying.Positive andyoungpeoplebeforethirddecade.Dayvisionisworse resultmeansatleast1/20or/10Snellenlinevision [4,27]. thannightanddimlight.Familyhistory,hemeralopia, PVEPtestisdescribedabove. photophobia,dyschromatopsiaandnystagmuscanbenoted SimulationofUnilateralAmblyopiaorBlindness It buttheydon'texistaltogethernecessarily [33,34]. Cone seemsrelativelyeasytomimicunilateralblindnessor functionsaredecreasedinERGaswellasVEP.Fundus amblyopia.Beforediagnosingassimulation,it'snecessaryto findingsarenotedlately.Bull'seyemaculopathyand ruleoutrealfunctionalororganicproblemsfromamblyopia, temporalopticatrophymayhelptodiagnose [14,23].Visual strabismus,orcornea,lens,vitreous,retinaandmaculaand fieldexaminationmayexposenormalorsometimespresent retrobulbarpathwaysproblems.Therearelotsofexamination ringorcentraldefectsandevenhemianopia.Diagnosis techniquestoinvestigateclaimsbutexaminermustperform dependsonhighindexofsuspicionandcolorvisiontest, theonesthathe/sheknowsindetailandisaccustomedto. tangentscreenexaminationandespeciallydiffusenarrowing Duringtheperformanceofthetestsexaminermustpay ofretinalarterioles [33,34]. attentiontosubjectnottounderstandthedetails (tricks)of Retrobulbarneuritis Unilaterallossofvisionandafferent thetests.Preparationsoftestsandequipmentshavetobe pupillarydefect(RAPD)arenoted.Historyisimportant. performedinabsenceofsubjectandexaminermustnot Viralinfectioninrecentdays,similarattacksinthehistory discusstestseventhesimplestdetail.Bilateralcomplete andpainwithglobemovementsareasked.Unilateral refractionofsubjectbeforetestsmustbeexamined.During dyschromatopsia,centralorcentrochecalaltitudinalfield examination,examinermustobserveeyesofsubjectbecause loss,dimvisionofenvironmentcanbeobserved.Vision anysingleblinkmayinterfereresultsoftest. amelioratesinonemonthin mostofthecases. Ifsomeorganicdiseasesinearlyphasecouldnotberealized PeriventricularplaquelesionsarereportedinMRIwith intime,misdiagnosisofsimulationcanbeinevitableandit contrastmatter [22]. 563 Simulationinophthalmology Chiasmaltumours Visionlossisobservedbeforeoptic diminishes.Againmalingerersdonotknowthemechanism atrophyandasymmetricalbitemporalhemianopiamanifests. ofthetest [4]. Afferentpupillarydefect(RAPD)andmasseffectinMRIor Verticalbartest Similartoanotherversionofthistest, CTscanwithcontrastdyeisobserved. whilesubjectreadsnewspaperfrom50cmatongueplateis Cortical blindness Besidesofnormalanteriorand placedinfrontofhis/herfaceto20cm.Ifvisionisgood posteriorsegmentexaminationsandpupillaryreactions, bilaterally,subjectcankeepreading.Butifoneeyeisweak bilateraltotalorneartotal(tubularvision)lossofvision andtongueplateisplacedbeforesoundeye,subjectgets exist.Frequentlyoccipitalinfarct,veryrarelymasslesionis distractedandchangeshis/herheadposition [4,5]. observedinMRimagingwithcontrastdye.Hemorrhageis Encouragetest Thistestisdefinedbefore. notexpected.Rarelyamnionfluidembolism,seriousuremia, Insomesituations,suchascompensationtrials,reminding postcoronaryangiographyvascularspasmcancausecortical thesimulatortheLEGALIMPLICATIONSthathe/she blindness.Neurologicaldefectslikeconfusion,disorientation, wouldsufferincasehe/sheisprovedtobeasimulator, epilepticattackandlateralizingfindingsarelookedfor.If wouldbeenoughtogettheresult. perimetrycouldbeperformedincasesoftubularvision, Nearvisionreadingtest Subjectisaskedtoreadnear leaningofdefecttoverticalmeridiancouldbeobservedand chartwiththebadeye.Ifhe/shecanreadsmallerletter it'susefulindifferentiationfromsimulation [22,28]. paragraphs,it'sthoughtthathe/shesimulates,becausenear Cancerrelatedretinopathy Somerarecasesofcancer readingwellrequiresreadingfaralso [3].Inthistest,subject relatedretinopathywouldexpresswithnonspecific mustwearhis/hernearglassesifnecessary.Ifdistantvision symptomslike decreasedvisualacuityandvisual isgoodbutnearvisionisabnormalexaminermustcheck phenomenalikefloaters.Infundusexaminationperhapsonly mediaopacitieslikepolarorposteriorsubcapsularcataracts [27]. arteriolarnarrowingwouldbeobserved.Thosecaseswould Low vision AID instrumentssometimesmayhelp bediagnosedwithhighsuspicionrateandparaneoplastic differentiation.Anhandheld2.2aphocaltelescopiclensover antibodytests.Visualfieldnarrowing,abnormaldark distantcorrectionisexpectedtoenhancevisiontwotimes [27]. adaptationandERGwouldbeusefulindocumentation [27]. Thistestmayrevealmalingeringifpatientsinsistonhis SubjectiveTestsforSimulationofUnilateralAmblyopia claimatbadnearvisiononly. orBlindness Pupillaryreactiontest Pupillaryreactiontestmaybe Optokinetictest Optokinetictest(mentionedabove)also helpful.Incaseofopticnervepathology,monocularvisual couldbeperformed.First,Baranycylinderrotatedwhentwo lossarelativeafferentpupillarydefect(RAPD)mustbe eyesopenedandnystagmusisobserved.Then,while observedonthateye [3,4,27].Butsomesmallmacularlesions cylinderkeepsrotatingexaminerclosesrapidlysoundeyeof maycausepoorvisionwithoutrelativeafferentpupillary subject,ifnystagmuspersistsitindicatesthatsubjectsees defect.Againbinocularvisuallossisobservedwithout withso-calledbadeye [3-5]. relativeafferentpupillarydefect [27]. Specialoptotypes Specialoptotypescouldalsobeused.If Pinholetest Apinholeisplacedbeforeofsoundeye,bad subjectwhocannotknowrealvisualequivalentofoptotypes eyeisleftopenandsubjectisaskedtoreadoptotypesatfar. cooperatesandreadshonestly,his/hervisualacuitycouldbe Whilesubjectreadsletters,examinerslowlyplaysbuttonsof determined. trialframeanddrawspinholeoutofsoundpupilwithout Rulertest Whilesubjectreadsnearchartfrom50-60cm,a subject'sawareness.Ifsubjectkeepsreading,examinerlets rulerortongueplateisplacedinfrontofnosehorizontally himgoreadingtillthebottom[5,17]. from15-20centimeters(cm)andisagainaskedtoread. Convexlensfoggingtest Itisusedincaseswhichsubject Becauseofvisualfieldssuperposebinocularpersonsread complaintsasymmetricalvisualloss.Itisthemost easily.Arealmonocularsubjecthesitatesandcannotread [4,5]. performedvisualacuityassessmenttest [3-5].Infrontofthe Penciltest Similartorulertest,whilesubjectreadsanear soundeye,theconvexlensesareplacedwithgradually chart,examinerslowlyplaceapencilbeforethesoundeye increasingpowerupto+8.0dioptertopreventseeing withoutsubject'sawareness.Ifsubjectreallyhasaproblem optotypesfrom5meters.Everytimeofincreasesubjectis inbadclaimedeye,he/shecan'tkeepreadingeasily [3,17]. reassuredandvisualacuitiesreexaminedtoconfusehim/her. Mirrortest Thistestisdefinedbefore.Itcouldbe Another+3.0diopterlensisplacedinfrontofsocalled performedwiththehelpofalongmirrorandsimulatorscan weakeye.Thenbinocularitytests(Worthfourdot) notsuspectthemechanismandcannotstoptofollowtheir performedespeciallypayingattentionnottoblinkeyes. reflectioninmirror [3-5,22,35]. Afterthat,removing+3.0dlens,+1.0and-1.0diopter Ontheotherhand,inthesecondversionoftestwithSnellen lensesareplacedoneafteranotherrepeatedlyonweakeye Chartvisualacuitydoubleswhendistanceanhalf andatlastlefteyeisneutralizedwhilebotheyesareopen.It 564 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 4熏晕燥援 5熏 Oct.18, 圆园11 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-83085628 耘皂葬蚤造押陨允韵援圆园园园岳员远猿援糟燥皂 isaclassicalfoggingtest.Subjectthenbelievesthathe/she eye,andplaces4prismlensbaseuponsoundeyeandapex seesbilaterallyandhe/shereadsalloptotypeswithhis/herso oflensdividespupilintotwoparts.Ifprismisplacedin calledbadeye,buthe/shedoesn'tknowthereality.Ifsubject correctplace,monocularverticaldiplopiaoccurs.Examiner doesn'trespondsincerelyandrepliesinacontradictory asksifsubjectseestwolinesonfarreallyinthesameclarity, manner,thenexaminerplaces+8.0diopterlensinfrontof thepossibleanswerwillbeyes.Thenexamineropensthe soundandbadeyesoneafteranotherandconfoundsthe badeye,andjustatthattimehe/sheturnsbaseofthe subjectuntilhe/sherespondsthetruth. prismaticlensdown.Now,binoculardiplopiaturnsout,but Cycloplegia test Sightofsubjectisblurredwith subjectthinkshe/shehasmonoculardiplopiayet.Atthat cyclopentolatedrops2or3timesonthesoundeye,andon pointoptotypesatfarareaskedtoreadonebyone,subject thesocalledbadeyebutwithanotherdropperfilledwith thinksthathe/shereadswithsoundeyeandreadsallthe serumphysiologicalandlabeledthesamewiththe lettershe/shecould.Butinrealityhe/shereadswithbadeye. cyclopentolate.After45minutessubjectisaskedtoread Withthistest,it'spossibletogetperfectvisualacuity from5meterseyesseparatelyclosed,eyewith examinationresultsfromeventheworstcooperatedcases [17,36]. cyclopentolatereadsfrom5meterseasily,butsubject It'sagoodtestforsimulationevaluation. refusessincerelytoreadwithsocalledbadeye.Thennear Duanetest Similartoprismtest,whilesubjectisreading readingbarJ3orJ4isaskedtoreadwithbotheyesopenthat nearchartbilateraleyesopen,examinerputs10prism means subjectcanreadwithonlybadeyewithout diopterbaseuplensonbadeye,andifsubjecthesitateseven cyclopentolate.Subjectreadsbar'ssmallestparagrapheasily onesecond,it'ssimulation [5]. thinkingthathe/shereadsbinocular [5,17]. Synoptofortest Whentwofusionpictures(rabbitand Coloredlenstest Subjectisrefractedandcorrectedand cage)areshownandsubjectcanseesimultaneouslybothof toldthathe/shewillhavenoprobleminreadingwithcolored them,itmeansgoodbinocularvisionispresent [5]. lenses.Whenviewingwithcoloredlensofletterswith Polarisationtest Subjectwearslensesthatrefractslight differentcolorsonwhiteground,samecolorletterscan'tbe 180degreesinright,90degreesinleftandlooksto readwiththelenscoloredsame.Redlenstosoundeyeand polarizingoptotypesfrom6meters.Oneoptotypeinupperis greenlenstosocalledbadeyeareplacedandwhiteground seenwithoneeye,theotheroptotypeonbelowwiththe platewithsomelettersred,greenandblackonisshowedto othereye.Thatistosay,polarizinglensesdissociatethe subjectandaskedtoread.Ifsubjectisreallyamblyopicor eyes.Ifsubjectreadsalloptotypeswithbotheyesopen,it blindinoneeye,he/shereadsonlyblackletters,becauseeye meansthatsubjecteasilyseeswiththesocalledbadeyeto withredlensseesandreadsonlyblackletters,can'tseethe thesmallestoptotype.[5]. others.Ifsubjectcanseebinocular,thenreadsallthree Mojontest Thistestcomposedof10rowsofSnellenletter, coloredlettersasifblack.Becausegreeniscomplementary whichisofequalminimumangleofresolution.Malingering ofredandmakesreadgreenonesasifblack [12].Inanother isprovedifsuspectstateshe/shecannotreadtheletters versionofthistest,subjectwearscolorglasseswithredand below [37]. greenlenses,likeWorthtest.He/shereadlettersonthe Diploscopytest Inthistest,thereisascreendiameterof60 chart,onehalfred,theotheronegreen,reflectedfromchart cmperforatedbytransversholesandsubjectlooksfrom projectorwhenbotheyesopenwithglasses.Subjectcan screentoacartoonwrittenK,O,L,Awithmajiscules.Test readalllettersfilteredwithredandgreenlensesif principleisphysiologicaldiplopiaandrighteyeseesKand binocularlyhavegoodvision.Withthisprinciple,confused L,lefteyeOandA.Simulatorsittingfrontofdiploscopecan subjectcouldreadallletterswhichhis/hermaximum seealllettersifonlybotheyesaresound.Withthistest, capacityofvisionpermits [5]. visualacuitydiscriminationcouldalsobeassessedwith Thistestmaybeperformedwithishihara'scolorplates.Ifa appropriatesizeletters [29]. subjectcanreadIshiharaplatesitmeanshe/shecanseeat ObjectiveTestsforSimulationofUnilateralAmblyopia least5/10Snellenline [25]. orBlindness Prismtest [5,17] Thistestiswell-knownforthispurpose. Opticalcoherencetomography(OCT) OCTcanbeused Thistestcanbeperformedintwoforms.Inthefirstform, bothinunilateralandbilateralamaurosisexamination [38]. whilesubjectlookatoptotypesatfarwithsocalledweak Thistestisvaluableespeciallyforcasespresentingwith eye,4prismlensisplacedbaseoutinthateyeandthiseye opticdiscpallorresemblingopticatrophy.Inthistechnique, iscarefullyobservedwhilelookingatfarletters.Ifbadeye temporalnervefiberlayermeasurementisimportant.Cut-off moves,itmeansthattheeyeisfixedtothelettersprojected level,(whichisaround67.5 ,forparticularpopulation)can 滋 andcanseethem [5]. beusedincaseswithbilateralinvolvement.Normaltest Inthesecondformofthetest,examinerclosessocalledbad resultsmaydisclosemalingeringobjectively [38]. 565 Simulationinophthalmology Patternelectroretinography (PERG) PERGisauseful 1992;82(4):369-382 electrodiagnostictesttocomparebothretinasofsubjectas 17SinghalNC.Hystericalblindnessversusmalingering. 1972;20(4):173-178 wellasfordiagnosis,documentation,andquantificationof 18NuzziR,ChiadoPiatL.Outpatienttestsforvisualacuityevaluationin presentpathology.NormalPERGmeansbothoftheoptic malingerers:Areviewandpersonalexperience. 1994;26(5): nerveandthemaculaarefunctionallysound.PERGisof 175-82 useintwowaysinunexplainedvisuallosscases.First,it 19ChenCS,LeeAW,KaragiannisA,CromptonJL,SelvaD.Practicalclinical easilyidentifiesphotoreceptordysfunctionsyndromesthat approachestofunctionalvisualloss. 2009;14(1):1-7 20SchutzJS,MavrakanasNA.Thevalueoftheophthalmologicalindependent rarelymanifestinclinicalfundusexamination.Second, medicalexamination:Analysisof344cases. 2009;93(10): normalERGindicatesthatfixationisgoodandopticpicture 1371-1375 focusesgoodinretina [4].Thereforecombinationpattern 21ImrieFR,ChurchWH.Factitiouskeratoconjunctivitis(notanothercaseof ERGandVEPrecordingsarenecessaryinthemostof ocularMunchausensyndrome) 2003;17(2):256-258 [4] 22Ba ererT.[Functionalvisualloss-review]Fonksiyonel(organikolmayan) malingeringorconversioncases . 鬤 g rmekay plar -derleme. 2008;38(5):438-442 PVEPisdescribedabove. 觟 覦 覦 PVEP 23LawtonAW.Retrochiasmalpathways,highercorticalfunctionandnonorganic Multifocalelectroretinography(mfERG) mfERGcanbe visualloss.In:YanoffM,DukerJS.(Editors) ,MosbyElsevier usedtoassessfixationlosses,whichisnotrarein 2009,pp995-1000 malingerers.Also,increaseddiagnosticvalueofthistest 24BengtzenR,WoodwardM,LynnMJ,NewmanNJ,BiousseV.Thesunglasses whenusedcombinedwithPVEPhasbeendemonstrated [39]. signpredictsnonorganicvisuallossinneuroophthalmicpractise. 2008; 70(3):218-221 AnotherstudyreportsthatVEPandmfERGcombinationis 25ShindlerKS,GalettaSL,VolpeNJ.Functionalvisualloss. ofuseforbothlocalizetheareaofpathologyandcheckif 2004;6(1):67-73 visualpathwaysarenormal [39,40]. 26Kz ,Ayd nP.[Functionalvisualfieldloss]Fonksiyonelgrmekayb In: 觟 魻 覦 觟 覦 REFERENCES G rmealan elkitab .(Editor)Ayd nP.Istanbul,AksuKitabevi2005,pp 觟 覦 覦 覦 1VillegasRB,IlsenPF.Functionalvisionloss:Adiagnosisofexclusion. 229-237 2007;10(78):523-533 27LeavittJA.Diagnosisandmanagementoffunctionalvisualdeficits 2NeyJJ,VolpeNJ,LiuGT,BalcerLJ,MosterML,GalettaSL.Functionalvisual Options 2006;8(1):45-51 lossinidiopathicintracranialhypertension. 2009;9(116): 28KansuT.[Visualdisordersrelatedtocentralnervoussystem]Santralsinir 1808-1813 sistemihastal klar nabagl g rmebozukluklar .In:O爷DwyerPA,KansuT,Torun 覦 覦 覦 觟 覦 3Sobac G.[Functionallossinneurophthalmology]Nrooftalmolojidefonksiyonel N.(Editors)N rooftalmolojielkitab .Ankara,Güne Kitabevi2008,pp147-155 覦 觟 觟 覦 覦 kay plar.In:O'DwyerPA,KansuT,TorunN.(Editors)N rooftalmolojiElKitab . 29LimSA,SiatkowskiRM,FarrisBK.Functonalvisuallossinadultsand 覦 觟 覦 Ankara,G ne Kitabevi2008;pp.137-145 children. 2005;112(10):1821-28 俟 鬤 4BeattyS.Nonorganicvisualloss. 1999;75(882):201-207 30GrafMH,RoesenJ.Ocularmalingering.Asurprisingvisualacuitytest. 5GandhiR,AmulaGM.MalingeringinOphthalmology.eMedicinespecialties. 2002;120(9):756-760 .unclassifieddisorders.updatesep2,2009 31GrafMH.Informationfromfalsestatementsconcerningvisualacuityandvisual 6KeltnerJL,MayWN,JohnsonCA,PostRB.TheCaliforniasyndrome.Functional fieldincasesofpsychogenicvisualimpairment visualcomplaintswithpotentialeconomicimpact. 1985;92(3): 1999;237(1):16-20 427-435 32RodierDW,MayerDL,FultonAB.Assesmentofyoungamblyopes.Arrayvs 7ArnoldAC.Nonorganicvisualdisorders.In:AlbertDM,JacobiecFA(Editors) singlepictureacuities. 1985;92(9):1197-1120 PrinciplesandPractiseofOphthalmology.Philadelphia,Saunders;2000;pp 33ZervasJP,SmithJL.Neuro-ophtalmicpresentationofcondysfunction 4317-4324 syndromesintheadult 1987;7(4):202-218 8KeaneJR.Neuroophthalmicsignsandsymptomsofhyste 1982;32 34DhellemmesSD,VincentF,ArndtC,DrumareIB,HacheJC.Simplified (7):757-762 electroretinographyprotocolanddiagnosisofretinaldistrophiesinchidren 9ThompsonJC,KosmorskyGS,EllisBD.Fieldsofdreamersanddreamed-up 1999;22(3):383-387 fields.Functionalandfakeperimetry. 1996;103(1):117-125 35ZinkernagelSM,MojonDSDistancedoublingvisualacuitytest:areliabletest 10SavinoPJ.Thepatientwithfunctionalvisualdisorders.In:SavinoPJ,Feldon fornonorganicvisualloss. 2009;247(6): SE,KatzB,SlamowitzTL(Editors)Neuroophthalmology.SanFransisco 855-858 2003 36SlavinMLTheprismdissociationtestindetectingunilateralfunctionalvisual 11KatholRG,CoxTA,CorbettJJ,ThompsonHS.Functionalvisualloss.Follow loss. 1990;10(2):127-130 upof42cases. 1983;101(5);729-735 37MojonDS,FlueckigerP.Anewoptotypechartfordetectionofnonorganic 12ScottJA,EganRA.Prevalenceoforganicneuroophthalmologicdiseasein visualloss 2002;109(4):810-815 patientswithfunctionalvisualloss. 2003;135(5):670-675 38CiveleklerM,HaliliI,GündoganFC,Sobac G.Retinalnervefiberlayer 覦 13SlettebergO,BertelsenCT,HovdingG.Theprognosisofpatientswith thicknessanalysisinsuspectedmalingererswithopticdisctemporalpallor hystericalvisualimpairment. 1989;67(2):159-163 2009;57(5):365-370 14Ledoux-SkiveeC,LedouxA.Simulationetdissimulationenophtalmologie. 39WeinsteinGW,OdomJV,CavenderS.Visuallyevokedpotentialsand 2004;(291):29-36 electroretinographyinneurologicevaluation. 1991;9(1):225-242 15WellerM,WiedemannP.Hystericalsymptomsinophthalmology. 40RennerAB,KellnerU,TillackH,KrausH,FoersterMH.Recordingofboth 1989;73(1):1-33 VEPandmultifocalERGforevaluationofunexplainedvisualloss 16BarrisMc,KaufmannDI,BarberioD.Visualimpairementinhysteria. 2005;111(3):149-157

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