Ocularsurfacechangesindiabetes 窑ClinicalResearch窑 OcularsurfacechangesintypeIIdiabeticpatientswith proliferativediabeticretinopathy

1ShanxiEyeHospital,Taiyuan030002,ShanxiProvince, morphologicalabnormalitiesinthecornealepitheliaand China nervefiberswerealsoobservedinthePDRpatients. 2 CollegeofOptometryandOphthalmology,TianjinMedical · CONCLUSION: Ocular surfacechanges, including University,TianjinMedicalUniversityEyeInstitute,Tianjin bluntedcornealsensitivity,reducedtearsecretion,tear MedicalUniversityEyeHospital,Tianjin300384,China filmdysfunction,progressivelossofcornealepithelia 3DepartmentofOphthalmology,ShanxiMedicalUniversity anddegenerationofnervefibers,arecommonintypeII FirstHospital,Taiyuan030001,ShanxiProvince,China diabeticpatients,particularlyinthediabeticpatientswith 4DepartmentofOphthalmology,BeijingChuiyangliuHospital PDR.Thecornealsensitivity,fluoresceinstainingscores, AffiliatedtoTsinghuaUniversity,Beijing100022,China andthedensityofcornealepithelialcellsandnerve Co-firstauthors: YanGaoandYanZhang fibersinthediabeticpatientscorrelatewiththeduration Correspondenceto: BingLi.ShanxiEyeHospital,Taiyuan ofdiabetes.Therefore,ocularsurfaceofthepatientswith 030002,ShanxiProvince,[email protected] PDRshouldbeexaminedregularlybyconventional approachesandconfocalmicroscopytofacilitateearly Received:2014-05-20 Accepted:2014-06-17 diagnosisandtreatmentofkeratopathy. · KEYWORDS: typeIIdiabetes;proliferativediabetic Abstract retinopathy;ocularsurface;cornealsensitivity;confocal · AIM:Todetectandanalyzethechangesonocular microscopy;tearfilmbreak-uptime surfaceandtearfunctionintypeIIdiabeticpatientswith DOI:10.3980/j.issn.2222-3959.2015.02.26 proliferativediabeticretinopathy (PDR),anadvanced stageofdiabeticretinopathy (DR),usingconventional GaoY,ZhangY,RuYS,WangXW,YangJZ,LiCH,WangHX,Li ophthalmictestsandthehigh-resolutionlaserscanning XR,LiB.OcularsurfacechangesintypeIIdiabeticpatientswith confocalmicroscopy. proliferativediabeticretinopathy. 2015;8(2):358-364 ·METHODS:Fifty-eightpatientswithtypeIIdiabetes wereselected.Basedonthediagnosticcriteriaandstage INTRODUCTION classificationofDR,thepatientsweredividedintothe urrently,anestimateof347millionpeopleintheworld non-DR (NDR)groupandthePDRgroup.Thirty-six C hasdiabetes,makingitoneofthemostcommon patientswithcataractbutnootherocularandsystemic medicalconditionsworldwide [1].Diabeteshasreceived diseasewereincludedasnon-diabeticcontrols.Allthe widespreadattentioninthatitcauseslife-threateningor patientsweresubjectedtotheconventionalclinicaltests debilitatingcomplicationsinheart,kidney,brain,andeye [2]. of cornealsensitivity,Schirmer Itest, andcorneal Intheeye,diabeticretinopathy(DR),cataract,glaucoma, fluoresceinstaining.Thenon-invasivetearfilmbreak-up keratopathy,chronicdryeye,andrefractiveabnormalitiesare time(NIBUT)andtearinterferometrywereconductedby [3] aTearscopePlus.Themorphologyofcornealepithelia thediseasesassociatedwithdiabetes .Amongthese andnervefiberswasexaminedusingthehigh-resolution diseases,DR,characterizedbyexudates,microaneurysms, confocalmicroscopy. andhemorrhages,isthemajorocularcomplicationof diabetes [4].Besidesthedisordersinretina,theincidenceof · RESULTS:TheNDRgroupexhibitedsignificantly cornealabnormalitiesisalsohighindiabetes.Literatures declinedcornealsensitivityandSchirmerItestvalue,as haveshownthatthediabeticshaveanincreasedriskof comparedtothenon-diabeticcontrols ( <0.001).The PDR group showed significantly reduced corneal developingcornealepithelialfragilityanddefects,decreased sensitivity, Schirmer I test value, and NIBUT in cornealsensitivityandthickness,abnormalwoundhealing, [5-9] comparisontothenon-diabeticcontrols ( <0.001). andincreasedsusceptibilitytoinfectedcornealulceration . Cornealfluoresceinstainingrevealedtheprogressively Forexample,Schultz [10] reportedthat47%-64%of injuredcornealepitheliainthePDRpatients.Moreover, diabeticpatientssufferedfromkeratopathies.Didenko [11] significantdecreaseinthecornealepithelialdensityand showedthatashighas73.6%ofthepatientswithdiabetes 358 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 8熏晕燥援 2熏 Apr.18, 圆园15 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-82210956 耘皂葬蚤造押ijopress岳员远猿援糟燥皂 hadcornealcomplications,includingpunctatekeratopathy, females(22eyes),theageofthePDRpatientsrangedfrom pannus,endothelialdystrophy,andcornealulcer. 34to62y(mean50 9y). 依 TheprevalenceandinterventionsofDRhavebeenstudied Thediabeticpatientsandthecontrolswererecruitedfrom extensively [12-15].However,theocularsurfacedisordersinthe December2011toMay2013inourhospital.TheHbA1Cof diabeticpatientswithDRhavebeenrarelystudied,andthe allthediabeticpatientswasmaintainedbetween6%and7% correlationbetweentheseverityofthesedisordersandthatof byeithermedicinaltreatmentordietarycontrolandexercise. DRremainsunknown,despitethattheincidenceoftheocular Noneofthepatientshadahistoryofophthalmictraumaor surfacedisordersisashighasretinaldisordersinthepatients operation,andnoneworecontactlenses.Thecorneas withDR [16,17].Therefore,thisstudyaimstoexaminethe appearedtransparentbyslip-lampexamination,andthe functionalandpathologicalchangesonocularsurfaceinthe intraocularpressurewasnormalforallthepatients. diabeticpatientswithproliferativeDR (PDR),anadvanced CornealSensitivityTest Cornealsensitivitywasexamined stageofDRandthediabeticpatientswithoutDR.The usingaCochet-Bonnetesthesiometer(LuneauSA,France). cornealsensitivity,tearsecretion,tearfilmfunction,corneal Thepatientsatandfacedforward.Afullyextendednylon epitheliaandnervefiberswereexaminedbyconventional filament(length:60mm;diameter:0.12mm)wasusedfor andconsideredassensitiveapproaches.Theresultsofthis theexamination.Thetipofthenylonfilamentwasapplied studydemonstratedtheincidenceandseverityofocular perpendicularlytothesurfaceofcentralcorneaand surfacedisordersinthediabeticswithPDR,indicatingthe progressedsteadily.Thelengthofthefilamentwasdecreased importanceofearlydiagnosisandtreatmentofkeratopathyin 5mmeverytimetillthepatientreportedthesensationof thesepatients. foreignbodyonthecornea.Thelengthofthenylonfilament SUBJECTSANDMETHODS wasthenrecorded.Thetestsofallthepatientswererepeated Subjects Fifty-eightpatients(74eyes)werediagnosedwith threetimesbythesameexperienceddoctorwhohadbeen non-insulin-dependentdiabetesmellitus [(NIDDM)27men maskedforpatientgrouping.Thetestresultswereconfirmed and31women]accordingtothediagnosticcriteriafor byanotherdoctor. NIDDMapprovedbyWorldHealthOrganization [18].The SchirmerITest Apieceoffilterpaper(5 35-mm2)was 伊 meanageofthediabeticpatientswas50 8y(rangingfrom foldedinoneend.Thefoldedendwasplacedintotheaccus 依 32to62y)withthedurationofdiabetesrangingfrom5to conjunctivaeat1/3mid-exteriorofthelowereyelidwithout 15y(mean9 3y).Inaddition,36cataractpatients(21males topicalanesthesia.Thepatientwasaskedtoclosetheeye 依 and15females)betweentheageof34and61y(mean52 gently.Thefilterpaperwaswithdrawn5minlater,andthe 依 8y)withoutanyotherocularandsystemicdiseasewere lengthofthewettedcreasewasmeasured. recruitedascontrolsubjects.Thecataractpatientswere CornealFluoresceinStaining Thestainingstripcoated enrolledforthecontrolsubjectsbecauseoftheirabundance withfluoresceinwasplacedintheconjunctivasacofthe andavailabilityinourhospital.Althoughthechangesin patient'slowereyelid.Thepatientwasaskedtocloseeyes cornealopticalproperties,suchasastigmatismandhighorder for5sandblinkseveraltimes.Corneastainingwasthen aberrations,havebeenreportedinthepre-operativecataract examinedusingaslitlampunderthecobaltbluelightand patients,thechangesintheparameterstobemeasuredinthis scored0-3accordingtotheareaandintensityofthestaining. studyhaverarelybeenreportedinsuchpatients [19,20].All 0:nostaining;1:sporadicpunctuatedstaining;2:dense proceduresofthisstudywereapprovedbytheethical punctuatedstaining;and3:intensepatchystaining. committeeinShanxiEyeHospitalandinaccordancewiththe Non-invasive Tear Film Break-up Time The tenetsoftheDeclarationofHelsinki.Informedconsentwas non-invasivetearfilmbreak-uptime(NIBUT)wasmeasured obtainedfromalltheparticipants. byaTearscopePlus(Keeler,UK)aspreviouslydescribed[21]. Therewasnosignificantdifferenceinage(F=0.358, =0.701) Briefly,theimageofthepatient'scorneawasmonitoredby orgender(2=0.217, =0.897)betweenthediabeticand thedoctorfromthemonitoringholeinthemirrorat1to2cm controlgroups.Basedontheresultsofbinocularindirect infrontofthepatient'seye.TheNIBUTwascalculatedfrom ophthalmoscope,fundusfluoresceinangiography,aswellas thetimewhenpatientstartedgazingaheadafterseveral theclassificationcriteriaofDR,thediabeticsweredivided blinkstowhenthecorneaangularimageappeareddistorted. intotwogroups.Thepatientswithoutdetectablefundus TearInterferometryTest Thetearinterferometrytestwas changeswereincludedasnon-DR (NDR)group,andthose conductedusingaDR-IITearscopePlus(Kowa,Japan). withPDRchangesinfunduswereincludedasPDRgroup. Underilluminationofawhitelightbeam,theinterference TheNDRgroupwascomposedof28patients(34eyes),13 patternsofthetearfilmlipidlayerwereanalyzedandgraded ofwhomweremale(16eyes)and15female(18eyes),aging fromItoVaccordingtotheYokoistandardsofgrading [22]. from32to59y(mean49 8y).ThePDRgroupcontained30 GradeIorgradeIIwasconsiderednormal,whereasgradeIII 依 patients(40eyes),including14males(18eyes)and16 oraboveabnormal. 359 Ocularsurfacechangesindiabetes CornealConfocalMicroscopy Thecornealendotheliaand nervefiberswereexaminedbyalaserscanningconfocal microscope(HeidelbergRetinaTomographyII,HRTII, Germany)equippedwithaRostockCornealModule.Briefly, thepatient'sheadwaspositionedanteroposterior,withthe mandiblerestingonthecheckbracketandtheforeheadin contactwiththeheadbandbracket.Theobjectivelens coveredwithadisposablesterilecontactcapforcorneawas positionedat5-10mminfrontofthepatient'scornea.The laserbeamwasadjustedtofocusonthecenterofthecornea. Theobjectivelenswasthenmovedforwardtillthecontact capslightlytouchedthecornea.Theimagesofcornea epitheliaandnervefiberswithdifferentdepthsandangles werecapturedandarchived. Figure1CornealsensitivitywasmeasuredbyaCochet- StatisticalAnalysis Datawereexpressedasmean SD.The 依 Bonnet esthesiometer Cornealsensitivitywas significantly differencesofcorneasensitivity,SchirmerItest,NIBUT,and reducedinbothNDRandPDRgroupincomparisontothe cornealnerveaxonaldensitybetweenthestudygroupswere non-diabeticcontrols;cornealsensitivityinthePDRgroupwasalso analyzedbyone-wayANOVAfollowedbyTukey -test.The significantlylowerthanthatintheNDRgroup. b <0.001. correlationsbetweentheexaminedparametersandthe diabeticdurationwereexaminedby Spearman'srank correlationanalysis.Thedifferencesinthepercentageofthe patientsgradedmorethanIIIintearinterferometrytest,and inthe percentage ofthepatientspositiveforcornea fluoresceinstainingwereanalyzedbyChi-squaretest.The differencesingendercompositionandcorneafluorescein stainingscorewereanalyzedbyranksumtest.Allthe statisticalanalyseswereperformedusingthesoftware SPSS13.0(SPSSInc.,SanDiego,CA,USA).A <0.05was consideredstatisticallysignificant. RESULTS CornealSensitivityTest Cornealsensitivitywasdecreased inbothdiabeticgroups(NDR:44 9mm,PDR:34 18mm) 依 依 Figure2BasictearsecretionwasmeasuredbySchirmerI ascomparedtothatinthecontrolgroup(53 7mm),and test BasictearsecretionintheNDRandPDRgroupwasboth 依 therewasstatisticalsignificancebetweeneitherdiabetic significantlylowerthanthatinthenon-diabeticcontrols.Thetear groupandthecontrolgroup(Figure1,both <0.001,NDR sectioninthePDRgroupwasalsosignificantlydiminishedas control,PDR control).Moreover,thecorneal comparedtothatintheNDRgroup. d <0.001. sensitivitymeasuredinthePDRgroupwasalsosignificantly lowerthantheNDRcounterpart(Figure1, <0.001,NDR thecontrolgroup(Figure2,both <0.001,NDR control, PDR),suggestingthatcornealsensitivitywasmore PDR control).Thepercentageofthepatientswith severelyaffectedinthepatientswiththeadvancedstageof SchrimerItestvaluelessthan5mmwas8.82%(3/34eyes) DR.Anegativecorrelationwasfoundbetweencorneal intheNDRgroup,15%(6/40eyes)inthePDRgroup,and sensitivityandthediabeticdurationbySpearman'srank only2.78%(1/36eyes)inthecontrolgroup.However, correlationanalysis(Spearman'scorrelationcoefficient=-0.657, Spearman'srankcorrelationanalysis showed thatthe =0.02).Thesefindingssuggestthereducedcorneal SchrimerItestvaluedidnotcorrelatewiththedurationof sensitivityalongwiththecourseofdiabetes. diabetes(Spearman'scorrelationcoefficient=-0.164, =0.122). Schirmer I Test Thevolumeoftearsecretionwas Theseresultssuggestthatsignificantreductionintear examinedbytheconventionalSchirmerItest.Theaverage secretionmightoccurevenbeforepathologiesofDRwere valueofSchirmerItestinthecontrolgroupwas20 5mm, detectedinfundus,andthisteardeficiencymightbe 依 whereasthevaluewasreducedto12 6mmintheNDR exacerbatedwhenDRprogressedintoanadvancedstage, 依 group,andevento9 6mminthePDRgroup(Figure2). althoughitdidnotcorrelatewiththedurationofdiabetes. 依 Highlysignificantdifferencewasfoundamongthegroups Corneal Epithelial Fluorescein Staining Thecorneal (F=19.2, <0.001)andalsobetweentheNDRorPDRand epithelialconditionwasexaminedbytheconventional 360 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 8熏晕燥援 2熏 Apr.18, 圆园15 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-82210956 耘皂葬蚤造押ijopress岳员远猿援糟燥皂 Table 1 Percentage of the patients positive for corneal fluorescein staining or graded higher than III in tear interferometry test Percentage of the patients positive for cornea fluorescein Percentage of the patients graded > III in tear Group staining interferometry test NDR 52.9% (18/34 eyes) 29.4% (10/34 eyes) PDR 85% (34/40 eyes) 52.5% (21/40 eyes) Control 38.9% (14/36 eyes) 16.7% (6/36 eyes) Χ 2 10.73 11.29 P <0.005 <0.004

fluoresceinstaining.Positivestainingwasdetectedin52.9% (18/34eyes)oftheNDRgroup,85%(34/40eyes)ofthe PDRgroup,and38.9%(14/36eyes)ofthecontrolgroup (Table1).ThecornealstainingscoreinthePDRgroupwas significantlyhigherthanthatinthecontrolgroup( <0.001, PDR control)andtheNDRgroup(<0.05,PDR NDR;Table1),andthestainingscoreinallthediabetic patientswaspositivelycorrelatedwiththediseaseduration (Spearman'scorrelationcoefficient=0.46, <0.05).These resultssuggestthatthedamagetotheintactnessofcorneal epitheliamaystartindiabeticpatientswithoutretinopathy, andthedamagebecomesmoresevereasdiabetesprogresses. Non-invasiveTearFilmBreak-upTime Thetearfilm Figure3NIBUTwasmeasuredbyaTearscopePlus The stabilitywasexaminedbyNIBUT.TheaverageNIBUTin NIBUTinthePDRgroupwassignificantlyshorterthanthatinthe thePDRgroupwas8 3s,beingonly53.3%and57.1%of NDRgroupandthecontrolgroup.TheNIBUTintheNDRgroup 依 f thatinthecontrolandtheNDRgroup(both <0.001,PDR wasnotsignificantlydifferentfromthatinthecontrols. <0.001. control,PDR NDR),respectively(Figure3).The 2 NIBUTmeasuredintheNDRgroupwassimilartothatinthe densityof4670 522cells/mm (Figures4A,4D).Afew 依 controls(Figure3, >0.05,NDR control).Thecorrelation swelledcellswithirregularshapewereobservedinthe wasnotfoundbetweentheNIBUTandthedurationof epitheliaoftheNDRgroup (Figure4B),andthedensityof 2 diabetes(Spearman'scorrelationcoefficient=-0.163, = theepithelialcellsinthisgroup(4612 601cells/mm )was 依 0.142).Theseresultssuggestthattearfilmstabilityhasnot comparabletothatinthecontrols (Figure4D).Incontrast, beenaffectedinthetypeIIdiabeticpatientswithoutDR,but manyexfoliated andedematousepithelialcellswere isprofoundlycompromisedinthepatientswithPDR. observedinthecorneaofthePDRpatients(Figure4C),and Thistestisdesignedtoanalyze thecelldensity(4121 474cells/mm2)wassignificantlylower TearInterferometryTest 依 thelipidlayerofthetearfilm,andhasbeenwidelyusedfor thanboththeNDRgroup(Figure4D, <0.05,PDR thediagnosisofdryeye.Thepercentageofpatientswhose NDR)andthecontrols (Figure4D, <0.05,PDR tearfilmwasgradedmorethanIIIwas29.4%(10/34eyes)in controls).Moreover,thecelldensityofthecornealepithelia theNDRgroup,52.5%(21/40eyes)inthePDRgroup,and indiabeticpatientswasnegativelycorrelatedwiththe 16.7% (6/36eyes)inthecontrolgroup(Table1).The durationofdiabetes(Spearman'scorrelationcoefficient=-0.311, Chi-squareanalysisrevealedasignificantdifferenceamong <0.05),indicatingaprogressivelossofepitheliaoverthe thegroups( 2=38.46, <0.001),andthepercentagesofthe courseofthedisease. patientsgradedhigherthanIIIintheNDRandPDRgroup Cornealconfocalmicroscopyalsoshowedthatcornealnerve werebothsignificantlygreaterthanthatinthecontrolgroup fibersinthePDRpatientshadslimaxons.Theseaxons (Table1, <0.05,NDR control; <0.001,PDR branchedlessandweremoretorturousthanthoseinthe control).Theseresultsindicatethatthequalityoftearfilm non-diabeticcontrolsandNDRgroup(Figure5A,5B,5C). lipidlayerwassignificantlycompromisedinpatientswith TheaxonaldensityofthenervefibersinthePDRgroup diabetes,anddryeyemaybemoreprevalentinthediabetics (802 264 m/field)reduced33.8%ascomparedtothatin 依 滋 thanthenon-diabeticpopulation. thecontrols(1212 223 m/field, <0.001,PDR control), 依 滋 Corneal Confocal Microscopy Cornealconfocal butwasnotsignificantlydifferentfromthatintheNDRgroup microscopyrevealedthatthethicknessoftheepitheliallayer (1118 234 m/field, =0.283,PDR NDR)(Figure5D). 依 滋 averagedat17 5 minalltheparticipants.Cornealepithelia Thedensityofnervefibersinthediabeticpatientswas 依 滋 ofthecontrolpatientsexhibitedregularcellshapewitha negativelycorrelatedwiththedurationofthedisease 361 Ocularsurfacechangesindiabetes

Figure4Cornealepithelialcellswereexaminedbyahigh-resolutionconfocalmicroscope A:Cornealepitheliafromthecontrols wereinaregularshapeandwithadiscernedcontour;B:TheirregularandswelledcornealepitheliawereobservedsporadicallyintheNDR group;C:Cornealepithelialexfoliationandedemawereseenmorefrequently,andtheepithelialcelledgeswereirregularandblurredinthe patientswithPDR;D:Scalebar=25 m.DensityofcornealepithelialcellswasmeasuredbyaHRT-IIconfocalmicroscope.Theepithelial 滋 celldensityinthePDRgroupwassignificantlylowerthanthecontrolsandtheNDRgroup. h <0.001.

Figure5Cornealnervefiberswereexaminedbyconfocalmicroscopy A:Inthecontrolgroup,nervefiberswerestraightandthick.The axonalfibersbranchedatacuteangles;B:IntheNDRgroup,nervefibersweremoretortuousandbranchedlessthanthoseinthecontrol group;C:ThenervefibersinthePDRpatientsweresparse,thinanddiscontinued.Thefibershadevenfewerbranchesandexhibitedmore tortuousaxonaltrajectoriesthantheNDRgroup.Scalebar=25 m;D:ThedensityofcornealnervefiberswasexaminedbyaHRT-II 滋 confocalmicroscope.ThenervefiberdensityinthePDRpatientswassignificantlydecreasedascomparedtothatintheNDRandthecontrol group. j <0.001.

(Spearman'scorrelationcoefficient=-0.473, =0.010).These importanceofexaminingand treatingocularsurface confocalmicroscopicobservationsreflecttheprogressive disordersinthediabeticpatients,particularlythepatients diabeticneuropathyonthecornea,whichmightbethe withPDR. neuroanatomicalbasisofthebluntedcornealsensitivityinthe Tearfilmprovidesnutritiontothecorneaandpreventsthe diabeticpatientswithPDR(Figure1). corneafromdrynessandkeratinization [24].Abnormalitiesin DISCUSSION tearamountortearfilmfunctionleadtoocularsurface AlthoughDRisoneofthemajordiabeticcomplicationsand disorders,suchaschronicdryeyeandkeratitis [25].The theleadingcauseofblindnessintheworkingagepopulation Schrimer'stestandtearfilmbreak-uptimeareconventional worldwide,theocularsurfacedisordersinthepatientswith methodsformeasurementoftearquantityandtearfilm DRhavenotacquiredasmuchattention [23].Therefore,the stability,respectively;whereastheDR-IITearscopePlus ocularsurfacechangeswereexaminedinthecurrentstudyin deviceemployedinthisstudyobjectivelyandnon-invasively thetypeIIdiabeticpatientswithPDRandthosewithoutDR. quantifiestheamountoftearproductionandanalyzesthetear Theconventionalclinicaltests,suchascornealsensitivity, filmlipidlayer [26,27].Tothebestofourknowledge,thisisthe SchirmerItest,andcornealfluoresceinstaining,the firstdynamicobservationoftearfilmintypeIIdiabetic non-invasiveapproachesusingtheTearscopePlus,andthe patientsusingthisdevice.Theresultsofourstudyshowed consideredmoresensitiveconfocalmicroscopy were thatthestabilityofthetearfilm,asindicatedbyNIBUT,in employedintheexaminations.Asaresult,theocularsurface theNDRpatientswasnotsignificantlydifferentfromthe changes,includingthedeterioratedcorneal sensitivity, non-diabeticcontrols(Figure2),however,thetearfilm reducedtearsecretion, compromisedcornealepithelial functiondetectedbyinterferometrytestinthisgroupwas intactnessandtearfilmquality,aswellastheprogressive significantlycompromised(Table1).Theseresultsare lossofcornealepitheliaanddegeneratedcornealnervefibers, consistentwiththosefromthepreviousstudiesusing werefoundinthesepatients.Thesefindingshighlightthe conventionalSchirmerItestandtearfilmbreak-uptimein 362 陨灶贼允韵责澡贼澡葬造皂燥造熏灾燥造援 8熏晕燥援 2熏 Apr.18, 圆园15 www.IJO.cn 栽藻造押8629原愿圆圆源缘员苑圆 8629-82210956 耘皂葬蚤造押ijopress岳员远猿援糟燥皂 diabetic patients [6,28,29].More importantly,theresults observedinthePDRpatientsbyconfocalmicroscopy measuredbytheDR-IITearscopePluscouldbeabnormal (Figure5).Theseresultsareconsistentwiththeprevious eveniftheconventionalSchirmerItestvaluewasnormal. reportsfrombasicandclinicalresearch.Forexample,Li Thisisprobablyduetoanincreasedtearreflectivity [30] and [40] observedsparsenerveplexuses,thinaxonfibers, suggeststhattheDR-IITearscopePluscouldbemore irregularfibrildistributionanddegenerationofmitochondria sensitiveandobjectivethantheSchirmerItest,supporting inalloxan-induceddiabeticrabbits.Moreover,Chang [41] thefurtherclinicalusageofthisdevice. showedthatthepatientswithtypeIIdiabetesexhibited Duetotheinstabilityandmalfunctionoftearfilm,diabetic significantlyreducedcornealnervefiberandnervebranch patientsaresusceptibletodryeye.Ithasbeendemonstrated density,aswellaselevatednervetortuositycoefficientas thattheincidenceofdryeyeis70%intypeIIand57%in comparedtothehealthycontrolsubjects.Furthermore,taken typeIdiabeticpopulation[31].Indeed,theresultsofourcorneal togetherwiththeresultsofcornealsensitivitymeasuredin interferometrytestshowedthatdryeyesyndromewasmore thisstudy(Figure1),theprogressivedamageinthecorneal prevalentindiabeticpatientsthaninthecontrols (Table1), nervefiberscausedbydiabeticneuropathymay,atleastin whichisconsistentwiththepreviousreportthatthereisan part, accountforthereducedcornealsensitivitythat associationbetweendryeyesyndromeanddurationoftypeII correlateswiththeseverityofDRandthedurationof diabetes [32].Themechanismsunderlyinghigherincidenceof diabetes(Figures1and5).Ontheotherhand,corneal dryeyeindiabeticpatientsremaintobeinvestigated.Grus confocalmicroscopyisconsideredasasensitiveapproach [33] havespeculatedthatthediminishedstimulatingsignals thatdetectsmorphologicalchangesincornealnervefibers fromocularsurfacetolachrymalglandcausedbytheblunted beforeasignificantreductionincornealsensitivityoccurs, cornealsensitivityandthe weakenedlachrymalgland hence,itallowsforearlierdetectionofsubtlediabetic regulationmayaccountforthehigherincidenceofdryeyein neuropathyinthecorneathanconventionaltestofcorneal thediabetics.Inaddition,theimpairedmainlachrymalgland sensitivity. secretiontogetherwiththedecreasedmucinproductionin Ingeneral,ocularsurfacechangesareassociatedwiththe diabeticpatientsmayalsoprovideanexplanation [34]. typeIIdiabeticpatientswithPDRthatmanifestasreduced Thequalityoftearlipidlayerandthestabilityoftearfilmare tearproduction,compromisedtearfilmquality,progressive correlatedwiththeindexofsuperficialpunctatekeratopathy[35]. lossanddamageofcornealepithelia,anddegenerationof Therefore,thedecreasedproductionoftearsandtheimpaired cornealnervefibers.Correlationanalysesfurthersuggestthat tearfilmfunctionindiabeticpatientsrenderthemsusceptible cornealchangesarecorrelatedwiththedurationandseverity tocornealepithelialexfoliationandedemaduringcataract ofdiabetes.Therefore,clinicalexaminationsofdiabetic andfundussurgery.Moreover,thesepatientsarealso patientsshouldincludethetestsperformedinthisstudy, afflictedbypersistentdefectsandslowregenerationof particularlythecorneasensitivityandtearfilmfunctiontests cornealepithelia,aswellasbullouskeratopathy [6,9].Infact, inthepatientswithalonghistoryofdiabetesandPDR. althoughthecorneasofthePDRpatientsinthecurrentstudy Confocalmicroscopyprovidesanon-invasiveandprecise appearedtransparentandundamagedunderaslitlamp, examinationofcornealepitheliaandnervefibers,and irregularshapeandedemaofthecornealepithelialcellswere facilitatesearlydiagnosisofdiabetic keratopathyand revealedunderahigh-resolutionconfocalmicroscope(Figure neuropathy,thusmaybeusedintheocularsurface 4A).Theseresultsareconsistentwithpreviousfindings [36]. examinationofthediabeticpatientswithPDR. However,thisstudyidentifiedasignificantreductioninthe ACKNOWLEDGEMENTS cornealepithelialdensitybyconfocalmicroscopyinthePDR Foundations: SupportedbyShanxiChinaScientificand patients,thephenomenonthatwasnotobservedbefore TechnologicalProject(No.2007031096-1);Ph.D.Program (Figure4B) [36,37].Thisisprobablyduetothestrictcriteria Foundationof MinistryofEducationofChina(No. usedforsubjectinclusioninthisstudy.Moreover,thecorneal 20111202110008). confocalmicroscopyusedinthisstudyexaminesand ConflictsofInterest:GaoY, None; ZhangY, None; Ru comparescorneasatthesamepreciselocation,whichcould YS, None; WangXW, None; YangJZ, None; LiCH, unveilthesite-specificdifferencesbetweengroupsthatmight None; WangHX, None; LiXR, None; LiB, None. bemissedinthepreviousstudies [36,37]. REFERENCES Peripheralneuropathyisacommondiabeticcomplication [38]. 1DanaeiG,FinucaneMM,LuY,SinghGM,CowanMJ,PaciorekCJ,Lin JK,FarzadfarF,KhangYH,StevensGA,RaoM,AliMK,RileyLM, Cornealsensoryfibersarederivedfromtheophthalmic RobinsonCA,EzzatiM;GlobalBurdenofMetabolicRiskFactorsof branchoftrigeminalnervewiththeinputfromautonomic ChronicDiseasesCollaboratingGroup(BloodGlucose).National,regional, [39] nerve,therefore,theymaybeaffectedbydiabeticneuropathy . andglobaltrendsinfastingplasmaglucoseanddiabetesprevalencesince Indeed,thecornealnervefiberswithreduceddensity, 1980:systematicanalysisofhealthexaminationsurveysand scattereddistributionandtortuousaxonaltrajectorywere epidemiologicalstudieswith370country-yearsand2.7million 363 Ocularsurfacechangesindiabetes participants. 2011;378(9785):31-40 21LiraM,SantosL,AzeredoJ,Yebra-PimentelE,RealOM.Theeffectof 2Smith-PalmerJ,BrandleM,TrevisanR,OrsiniFedriciM,LiabatS, lenswearonrefractiveindexofconventionalhydrogelandsilicone- ValentineW.Assessmentoftheassociationbetweenglycemicvariability hydrogelcontactlenses:acomparativestudy. anddiabetes-relatedcomplicationsintype1andtype2diabetes. 2008;31(2):89-94 2014;105(3):273-278 22YokoiN,TakehisaY,KinoshitaS.Correlationoftearlipidlayer 3JosifovaT,SchneiderU,HenrichPB,SchraderW.Eyedisordersin interferencepatternswiththediagnosisandseverityofdryeye. diabetes:potentialdrugtargets. 2008;8(2): 1996;122(6):818-824 70-75 23AntonettiDA,KleinR,GardnerTW.Diabeticretinopathy. 4FongDS,AielloLP,FerrisFR,KleinR.Diabeticretinopathy. 2012;366(13):1227-1239 2004;27(10):2540-2553 24King-SmithPE,BaileyMD,BraunRJ.Fourcharacteristicsandamodel 5InoueK,KatoS,OharaC,NumagaJ,AmanoS,OshikaT.Ocularand ofaneffectivetearfilmlipidlayer(TFLL). 2013;11(4):236-245 systemicfactorsrelevanttodiabetickeratoepitheliopathy. 2001;20 25StevensonW,ChauhanSK,DanaR.Dryeyedisease:an (8):798-801 immune-mediatedocularsurfacedisorder. 2012;130(1): 6CousenP,CackettP,BennettH,SwaK,DhillonB.Tearproductionand 90-100 cornealsensitivityindiabetes. 2007;21(6): 26GuillonJP.UseoftheTearscopePlusandattachmentsintheroutine 371-373 examinationofthemarginaldryeyecontactlenspatient. 7LjubimovAV,HuangZS,HuangGH,BurgesonRE,GullbergD,Miner 1998;438:859-867 JH,NinomiyaY,SadoY,KenneyMC.Humancornealepithelialbasement 27UchidaA,UchinoM,GotoE,HosakaE,KasuyaY,FukagawaK,Dogru membraneandintegrinalterationsindiabetesanddiabeticretinopathy. M,OgawaY,TsubotaK.Noninvasiveinterferencetearmeniscometryindry 1998;46(9):1033-1041 eyepatientswithSjogrensyndrome. 2007;144(2): 8LockwoodA,Hope-RossM,ChellP.Neurotrophickeratopathyand 232-237 diabetesmellitus. 2006;20(7):837-839 28GoebbelsM.Tearsecretionandtearfilmfunctionininsulindependent 9BikbovaG,OshitariT,TawadaA,YamamotoS.Cornealchangesin diabetics. 2000;84(1):19-21 diabetesmellitus. 2012;8(4):294-302 29YuL,ChenX,QinG,XieH,LvP.Tearfilmfunctionintype2diabetic 10SchultzRO,VanHornDL,PetersMA,KlewinKM,SchuttenWH. patientswithretinopathy. 2008;222(4):284-291 Diabetickeratopathy. 1981;79:180-199 30LiJ,ShenM,WangJ,MaH,TaoA,XuS,LuF.Clinicalsignificanceof 11DidenkoTN,SmoliakovaGP,SorokinEL,EgorovVV.Clinicaland tearmenisciindryeye. 2012;38(3):183-187 pathogeneticfeaturesofneurotrophiccornealdisordersindiabetes. 31SeifartU,StrempelI.Thedryeyeanddiabetesmellitus. 1999;115(6):7-11 1994;91(2):235-239 12HuB,ZhangY,ZengQ,HanQ,ZhangL,LiuM,LiX.Intravitreal 32ManaviatMR,RashidiM,Afkhami-ArdekaniM,ShojaMR.Prevalence injectionofranibizumabandCTGFshRNAimprovesretinalgene ofdryeyesyndromeanddiabeticretinopathyintype2diabeticpatients. expressionandmicrovesselultrastructureinarodentmodelofdiabetes. 2008;8:10 2014;15(1):1606-1624 33GrusFH,SabuncuoP,DickHB,AugustinAJ,PfeifferN.Changesin 13ZhangL,DongL,LiuX,JiangY,ZhangL,ZhangX,LiX,ZhangY. thetearproteinsofdiabeticpatients. 2002;2:4 α-Melanocyte-stimulatinghormoneprotectsretinalvascularendothelial 34MantelliF,Massaro-GiordanoM,MacchiI,LambiaseA,BoniniS.The cellsfromoxidativestressandapoptosisinaratmodelofdiabetes. cellularmechanismsofdryeye:frompathogenesistotreatment. 2014;9(4):e93433 2013;228(12):2253-2256 14RutaLM,MaglianoDJ,LemesurierR,TaylorHR,ZimmetPZ,ShawJE. 35InoueK,OkugawaK,AmanoS,OshikaT,TakamuraE,EgamiF,Umizu PrevalenceofdiabeticretinopathyinType2diabetesindevelopingand G,AikawaK,KatoS.Blinkingandsuperficialpunctatekeratopathyin developedcountries. 2013;30(4):387-398 patientswithdiabetesmellitus. 2005;19(4):418-421 15YauJW,RogersSL,KawasakiR, .Globalprevalenceandmajor 36LiuXW,PangGX,WangZ. confocalmicroscopyobservation riskfactorsofdiabeticretinopathy. 2012;35(3):556-564 andevaluationofsensationindiabeticcorneas. 16YoonKC,ImSK,SeoMS.Changesoftearfilmandocularsurfacein 2005;41(10):920-923 diabetesmellitus. 2004;18(2):168-174 37QuadradoMJ,PopperM,MorgadoAM,MurtaJN,VanBestJA. 17AragonaP,GiuffridaS,DiStefanoG,FerreriF,DiBenedettoA,Bucolo Diabetesandcornealcelldensitiesinhumansby confocal C,CroM.Ocularsurfacechangesintype1diabeticpatients. microscopy. 2006;25(7):761-768 2002;506(PtA):667-672 38CharnogurskyG,LeeH,LopezN.Diabeticneuropathy. 18AlbertiKG,ZimmetPZ.Definition,diagnosisandclassificationof 2014;120:773-785 diabetesmellitusanditscomplications.Part1:diagnosisandclassification 39MullerLJ,MarfurtCF,KruseF,TervoTM.Cornealnerves:structure, ofdiabetesmellitusprovisionalreportofaWHOconsultation. contentsandfunction. 2003;76(5):521-542 1998;15(7):539-553 40LiJ,MaiC,HuY.Astudyonhistochemistryandelectronmicroscopyof 19ChenW,ZuoC,ChenC,SuJ,LuoL,CongdonN,LiuY.Prevalenceof cornealnervesinexperimentaldiabeticrabbits. cornealastigmatismbeforecataractsurgeryinChinesepatients. 1996;32(4):258-259 2013;39(2):188-192 41ChangPY,CarrelH,HuangJS,WangIJ,HouYC,ChenWL,WangJY, 20WangJ,TangX,ZhangS,LiLH.Changesinhighorderaberrationsof HuFR.Decreaseddensityofcornealbasalepitheliumandsubbasalcorneal anteriorandposteriorsurfacesofcorneabeforeandafter nervebundlechangesinpatientswithdiabeticretinopathy. phacoemulsification. 2008;44(12):1066-1071 2006;142(3):488-490

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