Retinal metabolic and structural alterations in response to aflibercepttreatment in neovascular age-related macular degeneration
Jakobsen, D. B., Torp, T. L., Stefansson, E., Peto, T., & Graussland, J. (2018). Retinal metabolic and structuralalterations in response to aflibercept treatment in neovascular age-related macular degeneration. ActaOphthalmologica.
Published in:Acta Ophthalmologica
Document Version:Peer reviewed version
Queen's University Belfast - Research Portal:Link to publication record in Queen's University Belfast Research Portal
Publisher rightsCopyright 2018 Wiley. This work is made available online in accordance with the publisher’s policies. Please refer to any applicable terms ofuse of the publisher.
General rightsCopyright for the publications made accessible via the Queen's University Belfast Research Portal is retained by the author(s) and / or othercopyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associatedwith these rights.
Take down policyThe Research Portal is Queen's institutional repository that provides access to Queen's research output. Every effort has been made toensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws. If you discover content in theResearch Portal that you believe breaches copyright or violates any law, please contact [email protected].
Download date:24. Nov. 2020
1
Title
Retinalmetabolicandstructuralalterationsinresponsetoaflibercepttreatmentinneovascularage‐
relatedmaculardegeneration.
Authors
DitteBorupJakobsen1,2
ThomasLeeTorp1,2
EinarStefansson3,4
TundePeto2,5
JakobGrauslund1,2
Affiliations
1. DepartmentofOphthalmology,OdenseUniversityHospital,Odense,Denmark.
2. DepartmentofClinicalResearch,UniversityofSouthernDenmark,Odense,Denmark.
3. UniversityofIceland,Reykjavik,Iceland.
4. LandspitaliUniversityHospital,Reykjavik,Iceland.
5. CentreforPublicHealth,Queen'sUniversityBelfast,Belfast,UK.
Correspondingauthor
ProfessorJakobGrauslund,MD,PhD,DMSci
DepartmentofOphthalmology
OdenseUniversityHospital
Sdr.Boulevard29
DK‐5000OdenseC,Denmark
Phone:+4565412782
Fax:+4566126387
E‐mail:[email protected]
2
Abstract
Purpose
Non‐invasive retinalmarkers of disease activity couldpave theway for individualized treatment in
neovascularage‐relatedmaculardegeneration(nAMD).Weaimedtoevaluateifretinalvascularoxygen
saturationandcalibrescouldpredicttheinitialtreatmentresponseafteraloadingphaseofintravitreal
afliberceptinnAMD.
Method
A total of 149 eyeswere included (nAMD, n=76; dry AMD, n=30; normal eyes n=43). Of these, 57
treatment‐naïveeyeswithnAMDreceivedthreemonthlyinjectionswith2.0mgafliberceptandwere
subsequentlystratifiedaccordingto functionalandstructuralresponseaccordingtodevelopment in
best‐correctedvisualacuityandmacularretinalthickness.Theretinalvascularoxygensaturationand
calibresweremeasuredpriortotreatmentandonemonthafterthethirdinjection.
Results
PatientswithnAMDanddryAMDhadhigherretinalarteriolaroxygensaturationascomparedtonormal
eyes(94.3%vs.95.2%vs.92.6%,p=0.04).Thirty‐nine(68.4%)and12(21.1%)eyeswithnAMDwere
functionalandstructuralresponders.Aftertheloadingphase,structuralnon‐respondersdevelopeda
higher retinal arteriolar (95.3% vs. 93.3%, p=0.03) and venular (64.7 vs. 59.4%, p=0.02) oxygen
saturation,andrespondersdevelopedalowerretinalarteriolarcalibre(118.0µmvs.114.3µm,p<0.01).
Inamultiplelogisticregressionmodel,increasingretinalvenularoxygensaturationassociatedwitha
negativetreatmentoutcome(oddsratio1.17foreach1%increment,95%confidenceinterval1.01‐1.36,
p=0.03).
Conclusion
Changes in the retinal venular oxygen saturation associate independently with initial treatment
response innAMD,but functionalandstructural retinalmeasurementsprior to treatmentcouldnot
predictthetreatmentresponse.
Keywords
Neovascular age‐related macular degeneration, choroidal neovascularization, aflibercept, retinal
oximetry,retinalvascularcalibre,diseaseactivity.
3
Introduction
Neovascularage‐relatedmaculardegeneration(nAMD)isthemostcommoncauseofblindnessinthe
elderly population (Ferris et al. 1984;Hoeg et al. 2016) affecting annually 6100 eyes per 1million
inhabitantsintheDanishpopulation(Buchetal.2005).
Repetitive intravitreal injections of vascular endothelial growth factor (VEGF) inhibitors has
demonstratedefficacy(Rosenfeldetal.2006;Brownetal.2009;Heieretal.2012),buttreatmentwith
frequentandcontinuouslyinjectionsisahugeburdenforthepatientsandthehealthcaresystem.
MultiplemechanismsareinvolvedinthedevelopmentofnAMD,andhypoxiahasbeenproposedasa
centralmediator.ItstimulatestheproductionofVEGF,whichpromotesneovascularizationandvascular
leakage(Folkman& Klagsbrun1987;Adamis& Shima2005;Ng& Adamis2005;Stefanssonetal.
2011).
Measurement of the retinal oxygen saturation can be performed non‐invasively by a
spectrophotometric retinal oximeter. In a cross‐sectional study, Geirsdottir et al. reported that in
patientswithtreatment‐naïvenAMD,retinaloxygensaturationandagewerepositivelycorrelatedas
compared to normal controls (Geirsdottir et al. 2014). This could indicate that the retinal oxygen
metabolismisalteredinnAMDandthatitmightserveasapotentialbiomarkeroftreatmentresponse.
Previous studies have also investigated structural changes in retinal vessel calibres after VEGF
inhibitionwithranibizumaborbevacizumabinnAMD(Papadopoulouetal.2009;Fontaineetal.2011;
Micielietal.2012;Tatlipinaretal.2012;Wickremasingheetal.2012;Mendrinosetal.2013;Pekeletal.
2015;Kurtetal.2017).Resultshavebeenconflicting,andasfarasweknow,thishasnotbeentestedin
responsetoaflibercepttreatment,whichhasreplacedranibizumabandbevacizumabinmanycentres.
Thisstudyaimedtoinvestigateifretinalmetabolismandstructureasgivenbyretinalvascularoxygen
saturation and calibresmay be used as non‐invasivemarkers for early treatment response after a
loadingphaseofthreemonthlyintravitrealafliberceptinjectionsineyeswithtreatment‐naïvenAMD.
Materialsandmethods
Recruitmentofpatients
AllpatientswererecruitedattheDepartmentofOphthalmologyatOdenseUniversityHospitalbetween
October2016andJanuary2017.Patientswithtreatment‐naïveeyeswithnAMDwereincludedinthe
prospectivestudy,andinacross‐sectionalcomparison,patientswithdryAMDaswellaseyeswithout
maculardiseasewererecruitedforbaselinecomparison.
Eyeswithpreviousretinallasertreatmentofanykindwereexcludedfromthestudy.Allpatientswere
only allowed to participate in the studywith one eye. If patients in the non‐nAMDgroupshad two
eligible eyes,we included the eyewith best imagequality (and chose the right eye if therewas no
differenceinimagequality).IntheprospectivestudyofnAMD,iftwoeyeswereeligible,weincluded
4
theeyethathadfollow‐upimaging,orifthiswasobtainedinbotheyes,weusedthesamealgorithmas
forthenon‐nAMDgroups.
Datawerecollectedonage,gender,smoking,diabetesandformercataractsurgery.Questionsabout
smokingweredivided into four categories: current smokers, smokingcessation<10years, smoking
cessation>10years,andnon‐smokers.Inthedataanalysis,thefirsttwogroupswerecombinedand
definedasthe“smoking”groupandthelasttwogroupsasthe“non‐smoking”group.
AllparticipantswereCaucasian.
Baseline
Allexaminationsweredoneineyesdilatedwithtropicamide10mg/mlandphenylephrinhydroclorid
10%. All diagnoses were initially given by trained physicians at the department, based upon
ophthalmoscopyandsweptsourceopticalcoherencetomography(SSOCT)(DRIOCTTriton,Topcon,
Tokyo, Japan). If nAMDwas suspected, fluorescein and indocyanine green angiography (Heidelberg
Spectralis, Heidelberg Engineering, Heidelberg, Germany) were performed. For all patients, the
diagnosiswassubsequentlyconfirmedbyaretinalspecialist(JG).DryAMDweredefinedasanynumber
ofmaculardrusenorgeographicatrophyseenonadisc‐centredfundusimage.
Best corrected visual acuity (BCVA) was measured according to the Early Treatment Diabetic
Retinopathy Study (ETDRS) scale. Intraocular pressure (IOP)was recorded (Icare tonometer, Icare
FinlandOy,Helsinki,Finland),andcentralretinalthicknesswasmeasuredbySSOCT.
Non‐invasiveretinalmeasurements
Measurement of retinal oxygen saturation and calibre was performed on disc‐centred 50° fundus
imagescapturedbyOxymapT1andanalysedwiththeOxymapAnalysersoftware(OxymapmodelT1,
Oxymap,softwareversion2.5.0,Reykjavik,Iceland).
Thecamera isbasedona funduscamera, takingtwo fundus imagessimultaneouslyat twodifferent
wavelengths. The 570 nm wavelength image is insensitive to oxygen as opposed to the 600 nm
wavelength. By calculating the difference in absorbance of light in the two images, the software
measuresandvisualises theoxygensaturation inone single imageusinga colourgridonall traced
vessels(Figure1)(Geirsdottiretal.2012).
Twocircleswereplacedontheopticdisccentredimage.Thefirstcirclewasmanuallyplacedaround
theedgeoftheopticdisc,20‐35pixelsawayfromtheedgeofthedisc.Thiswasdonetoavoidreflection
oflightfromtheretinalnervefibrelayeraroundthedisc,asthiscouldinfluencethemeasurementof
oxygensaturation.Thesecondcirclewasplacedconcentricaroundthefirstcircle,withadiameterat
threetimesthediameterofthefirstcircle.Allvesselmeasurementsweredonebetweentheinnerand
theoutercircle.Ineachimage,vesselmeasurementsweredoneon8vessels(oneretinalarterioleand
venuleineachquadrant).Vesselslargerthan6μmwereautomaticallydetectedandtracedforalength
of50‐200pixels.Measurementswereperformedineachvesselfromtheinnercircleuntilalengthof
5
maximumof200pixelswasreachedortothefirstbranchingofthevessel.Ifthebranchingoccurred
beforereachinga lengthof50pixels, thebranchwasmeasured instead.Thesoftwareautomatically
measured the mean retinal vascular oxygen saturation and vascular calibre in each chosen vessel
segment.Retinalarteriolarandvenularsaturationandcalibreweredefinedas themeanof the four
arteriolesandvenulesineachimage.
Measurementsandgradingwerecarriedoutbythesametrainedgrader(DBJ),accordingtoapredefined
protocol.Eyeswithanimagequalityoflessthan6.0(duetoblurrymedia)wereexcludedfromthestudy.
Atfollow‐up,measurementswererepeatedatthesamevessel‐segmentsthatwereusedatbaseline.Ifa
vesselgradedatbaselinewasungradableatfollow‐up,thequadrantwasleftungradedatfollow‐up.
Follow‐upandoutcomemeasurements
EacheyediagnosedwithnAMDreceived threemonthly injectionsof intravitreal2.0mgaflibercept.
Follow‐upwas conducted approximately onemonth after the last injection.At follow‐up, eyeswith
nAMDwereclassifiedasfunctionalandstructuralrespondersandnon‐respondersbasedonchangein
visualacuityandmacularthicknessfrombaselinetofollow‐up.Eyeswereclassifiedasfunctionalnon‐
responders if any decrease in BCVA were seen (≥1 ETDRS‐letters). In addition, structural non‐
respondersweredefinedasnochangeorincreaseinmacularthickness.
Statisticalanalyses
Demographicdataarepresentedasmedianwithinterquartilerange(IQR)forcontinuousdataandas
percentageforcategoricaldata.ComparisonofthethreegroupsatbaselinewasdoneusingKruskal‐
Wallisequalityofpopulationsranktestforcontinuousdata,andchi‐squaretestforcategoricaldata.For
statistical significant differences between groups,Wilcoxon rank‐sum test was used to identify the
groupthatdifferedfromthetwoothergroups.Forcontinuousdata,differencesbetweenresponders
andnon‐responderswerecalculatedbyWilcoxonrank‐sumtest,andforcategoricaldata,weusedchi‐
squaretest.Within‐groupdifferencesfrombaselinetofollow‐upwerecalculatedbyWilcoxonsigned‐
rank test for paired data. We tested the association between retinal oxygen saturation and best
correctedvisualacuity(continuousvariables)byusingthePearsoncorrelationcoefficient.
Multiplelogisticregressionanalysiswasperformedwithretinalvascularoxygensaturationandcalibre
as predictors for treatment outcome in a model adjusted for age, sex, smoking, diabetes and time
betweenlastinjectionandfollow‐up.P‐valuesunder0.05weredefinedasstatisticallysignificant,and
STATA14.2(StataCorp,CollegeStation,TX)wasusedforallstatisticaltests.
Approvals
TheprojectwasapprovedbytheRegionalScientificEthicsCommittee(IDS‐20160102),andtheDanish
Data Protection Agency (ID 16/35476). The project was conducted according to the tenets of the
DeclarationofHelsinkiandstandardgoodclinicalpractice.Allparticipantsgavewrittenconsentbased
onbothwrittenandoralinformationpriortoinclusion.
6
Results
Atotalof149eyesfrom149patientswereincludedinthestudy.Ofthese,76weretreatment‐naïveeyes
withnAMD,30wereeyeswithdryAMD,and43wereeyeswithoutretinalpathology(Table1,Figure
2).InthenAMDgroup,10eyesdidnotreceivetreatment,fiveeyeswerelostduringfollow‐up,retinal
imaging at follow‐upwas not possible in two eyes, and two eyes received two injections andwere
therefore excluded. Hence, 57 eyes with nAMDwere included in the prospective part of the study
(Figure2).Alleyesreceivedthreeinjections,andthetimebetweenthelastinjectionandfollow‐upwas
37.0±13.0days(median±IQR).
Patientswithtreatment‐naïvenAMD,dryAMDandnormaleyesarecomparedinTable1.Thegroup
withnormaleyeswereyounger thantheothergroups(p<0.01andp<0.01)andhada lowerretinal
arteriolar oxygen saturation thanpatientswith nAMD (p=0.02) anddryAMD (p=0.03). In addition,
patientswithnAMDhad lowerBCVAascompared toeyeswithdryAMD(p<0.01)andnormaleyes
(p=0.02).Thethreegroupsdidnotdifferaccordingtogender,smoking,diabetes,IOP,retinalvenular
oxygensaturationorretinalvascularcalibres.
Atbaseline,patientswhowere laterclassifiedas functional respondersandnon‐respondersdidnot
differaccordingtoage,sex,smoking,diabetes,formercataractsurgery,CNVtype,BCVA,IOP,andcentral
retinalthickness(Table2).However,atfollow‐up,BCVAwasbydefinitionhigheramongrespondersas
comparedtonon‐responders(70.0±24.0ETDRSlettersvs.56.5±23.0ETDRSletters,p=0.02).
Atbaselineandfollow‐upfunctionalrespondersandnon‐respondersdidnotdifferaccordingtoretinal
oxygensaturationorvascularcalibre,butbetweenbaselineandfollow‐uprespondersshowedatrend
towardsan increase inretinalarteriolaroxygensaturation(94.3±5.4%vs.95.0±4.4%,p=0.05)and
decreaseinretinalarteriolarcalibre(115.3±15.0μmvs.110.5±12.3μm,p<0.03)(Table3).
Atbaseline,patientswhowerestratifiedasstructuralrespondersandnon‐respondersdidnotdiffer
accordingtoage,sex,smoking,diabetes,formercataractsurgery,CNVtype,BCVA,andIOP.However,
macularthicknesswashigherinrespondingthannon‐respondingpatients(293.0±101.0μmvs.230.0
±44.5μm,p<0.01)(Table2).Nodifferenceswerefoundatfollow‐upbetweenthetwogroups.
Structuralnon‐respondershadanincreaseinarteriolarandvenularoxygensaturationfrombaselineto
follow‐up,(arteriolar93.3±3.3vs.95.3±2.8,p=0.03,venular59.4±11.1vs.64.7±6.5,p=0.02)andthis
incrementwashigherwhencompared tonon‐responders (arteriolar1.6±2.3.vs.0.5±1.7,p=0.03,
venular 3.9 ±7.9 vs. 0.1 ±5.3, p=0.03). In addition, the arteriolar calibre decreased frombaseline to
follow‐upinresponders(118.0±14.5.vs.114.3.±14.5,p=0.01)(Table3).
Inamultiplelogisticregressionmodel,adjustedforage,sex,smoking,diabetesandtimebetweenlast
injection and follow‐up, an increase in retinal venular oxygen saturation associatedwith anegative
7
initial structural treatment outcome (odds ratio for a full treatment response 1.17 for each 1.0%
increment,95%confidenceinterval1.01‐1.36,p=0.03,Table4).
Finally,anegativecorrelationwasseenbetweenbaselineretinalvascularoxygensaturationandchange
inretinalmacularthickness.Patientswithahigherretinaloxygensaturationatbaselinehadalarger
decreaseinmacularthicknessatfollow‐up(arteriolarp<0.01,venularp=0.03)(Datanotshown).
Discussion
Inthisstudy,weprospectivelydemonstratedretinalmetabolicandstructuralalterationsasashort‐
termresponsetointravitrealaflibercepttherapyinpatientswithtreatment‐naïvenAMD.
Theretinalarteriolarandvenularoxygensaturationwere foundto increaseat follow‐upinpatients
withanegativestructuralresponsetotheinitialtreatment.Inaddition,increasedretinalvenularoxygen
saturation independently associated with a 17% increased risk of an unchanged/higher macular
thickness after the loading phase. This could reflect underlying damage of the retinal vasculature
inducedbythepersistentdiseaseactivityinpatientswithoutapositivetreatmentresponseoftheinitial
treatment.
Inpreviousstudies,higherretinalvenularoxygensaturationshavebeendemonstratedinpatientswith
ischemicmaculardiseasessuchasnAMDanddiabeticretinopathy(DR)(Geirsdottiretal.2014;Rilven
etal.2017).Theremightalsobehigherretinalarteriolaroxygensaturationinsuchpatients,butthishas
notbeendemonstratedconsistently,potentiallyduetotheceilingeffectoftheretinalarteriolaroxygen
saturation,whichisoftencloseto100%(Rilvenetal.2017).Thefactthatwedidfindmetabolicchanges
in the retinal arteriolarandvenularoxygensaturationcouldbe seenas anexpressionof the subtle
vascularchangesseeninnAMD.Thediseasemechanismshouldbetakenintoaccountwhencomparing
studiesofnAMDandDR.IncontrasttothedisturbancesofthechoroidalbloodsupplyinAMD,DRaffects
theinnerretina,whichissuppliedfromtheretinalcirculation(Stefanssonetal.2011).
Inaprospectiveclinicalstudy,Bek&Jorgenseninvestigatedretinalmarkersfortreatmentresponsein
eyeswithdiabeticmacular oedema treatedwith three injectionsof ranibizumab (Bek& Jorgensen
2016).Theauthors foundthathighermeanarterialbloodpressureandarteriolaroxygensaturation
before treatmentwas associatedwith a decrease in visual acuity and an increase in central retinal
thickness. In contrast, innAMDwe foundhigher retinal arteriolarandvenularoxygensaturationat
baselinetobecorrelatedwithalowermacularthicknessatfollow‐up.Furthermore,developmentofa
higher arteriolar oxygen saturation after aflibercept loading associated with a negative structural
treatmentresponse.
As far as we know, the concept of retinal oxygen metabolism in nAMD, has only been tested by
Geirsdottir et al. that compared retinal oxygen saturation in eyes with nAMD and healthy eyes
(Geirsdottiretal.2014).Theyfoundtheretinalvenularoxygensaturationtobepositivelycorrelated
8
withageineyeswithnAMD(andviceversainhealthyeyes),butincontrasttoourstudy,theyfoundno
differences in retinal arteriolar oxygen saturation between eyes with nAMD and healthy eyes.
Geirsdottiretal.pointstowardsacorrelationbetweenhighervenularoxygensaturationandamore
severestateofnAMD.Methodologicaldifferencesbetweenthestudiescouldaccountforthedifferent
results.
Severalpreviousstudieshaveinvestigatedtheeffectofranibizumaborbevacizumabonretinalvascular
calibreineyeswithnAMD,andonerecentstudyhasinvestigatedtheeffectofaflibercept(Tetikogluet
al.2017).Thelatterwasaretrospectivestudythatincluded15treatment‐naïveeyeswithnAMDthat
weretreatedwiththreeafliberceptinjectionswith30daysfollow‐upafterthelastinjection.Theyfound
astatisticallysignificantretinalarteriolarvasoconstrictionaftertreatment,inpatientswithapositive
treatmentresponse,thesameresultswerefoundinourstudy.Furthercomparisonsbetweenthestudies
werenotpossible,giventhatonlytheirabstracthasbeenpublished.
The same pattern was also seen in studies of other VEGF‐inhibiting agents. Papadopoulou et al.
demonstrated adecrease in retinal arteriolar calibre in nAMDeyes treatedwith three ranibizumab
injections(n=11)(Papadopoulouetal.2009).Fontaineetal.alsofoundadecreaseinretinalarteriolar
calibreafterthefirstbevacizumabinjection,andthedecreasewasstillpersistentattheendofthestudy,
fiveweeksafterthethirdinjection(n=23)(Fontaineetal.2011).InthestudybyMicielietal.,therewas
asignificantdecreaseinarteriolarcalibreineyeswithnAMD,whichpreviouslyhadthreeorlessanti‐
VEGFinjectionswithranibizumab,butnochangewasseeninthegroupwithmorethanthreeinjections
priortotreatment.Onlytwoeyesinthestudygroupweretreatment‐naïve(n=15)(Micielietal.2012).
InthestudybyMendrionosetal.,decreasedretinalarteriolarcaliberwereseenafterthefirstofthree
injections with ranibizumab, and the difference was still present at 12 months follow‐up (n=10)
(Mendrinosetal.2013).Incontrasttothesestudies,Pekeletal.reportedofunchangedretinalvessel
calibrethreemonthsafterthreeinjectionswithranibizumab(n=32)(Pekeletal.2015).
The two biggest studies investigating the effect of ranibizumab and bevacizumab treatment on the
retinalcalibreinnAMDeyeswereperformedbyWickremasingheetal.(n=88)andKurtetal.(n=68)
(Wickremasingheetal.2012;Kurtetal.2017).InthestudybyKurtetal.,theycomparedbevacizumab
withranibizumabtreatmentineyeswithnAMD(Kurtetal.2017).Patientsweregivenoneinjectionand
followedforonemonth.Theyfoundanarteriolarvasoconstrictionineyestreatedwithranibizumab,
butnotineyestreatedwithbevacizumab.Nochangeswerefoundintheretinalvenularcalibreineither
group.InthestudybyWickremasingheetal.,patientswithnAMDweretreatedwiththreeranibizumab
injectionsandfollowedfor12months(Wickremasingheetal.2012).Theirstudypopulationwasvery
similartooursaccordingtoage(79.1±7.9years)andsex(64.2%females).Theyfoundthatpatients
whohaddecreasedvisualacuityatfollow‐uphadhigherretinalvenularcalibreatbaselinecomparedto
9
thosewhohadstableorimprovedvisualacuity.Noassociationwasfoundbetweenthearteriolarcalibre
andtreatmentoutcome.
Asinourfunctionalfindings,Kurtetalfoundarteriolarvasoconstrictiononeweekandonemonthafter
treatmentwithranibizumab,butnotbevacizumab,ineyeswithnAMD(Kurtetal.2017).
Asasecondaryendpoint,wefoundtheretinalarteriolaroxygensaturationtobehigherinAMD(dryand
neovascularalike)ascomparedtohealthyeyes,eventhoughthegroupswerenotperfectlybalanced
accordingtoage.Thus,wecannotconcludeifthehigheroxygensaturationwascausedbythedisease
orreflectedbythehigherageintheAMDgroups.
Strengthsofourstudyincludetheprospectivedesignwithastrictclassificationoftreatmentresponse
basedonclinicallyrelevantwell‐definedcriteria.Inaddition,allpatientsweretreatedwiththesame
drugatthesamehospital.Ontheotherhand,limitationsshouldbeacknowledged.Intheprospective
partofthestudy,weonlyfollowedpatientsaftertheloadingphasewithnointermediarymeasurements,
thenumberofparticipantswaslimited,andinfluencebymasssignificancecannotberuledoutinthe
statisticalanalysis.Inaddition,systemicmeasurementslikearterialbloodpressurewerenotavailable.
In conclusion, we found higher retinal arteriolar and venular oxygen saturation in patients with a
structuralnegativetreatmentresponse,andadecreaseinretinalarteriolarcalibreinpatientswitha
positive treatmentresponse toaflibercept treatment.Even thoughretinalmetabolismandstructure
prior to therapy could not be used to predict treatment response after three monthly aflibercept
injections, our findings points to a metabolic alteration in eyes with nAMD who do not respond
sufficiently.Long‐termstudieswouldbeneededtotellifthiscouldbeusedasapotentialmarkerthat
canbeusedforclinicalguidanceintherapy.
Acknowledgements
ThestudywasfinanciallysupportedbytheVeluxfoundation.ThestudywaspresentedattheEuropean
AssociationforVisionandEyeResearch(EVER)congressinNicethe29thofSeptember2017.
10
References
AdamisAP&DTShima(2005):Theroleofvascularendothelialgrowthfactorinocularhealthand
disease.Retina25:111‐118.
BekT&CMJorgensen(2016):TheSystemicBloodPressureandOxygenSaturationinRetinal
ArteriolesPredicttheEffectofIntravitrealAnti‐VEGFTreatmentonDiabeticMaculopathy.
Invest.Ophthalmol.Vis.Sci.57:5429‐5434.
BrownDM,MMichels,PKKaiser,JSHeier,JPSy,TIanchulev&ASGroup(2009):Ranibizumabversus
verteporfinphotodynamictherapyforneovascularage‐relatedmaculardegeneration:Two‐
yearresultsoftheANCHORstudy.Ophthalmology116:57‐65e55.
BuchH,NVNielsen,TVinding,GBJensen,JUPrause&MlaCour(2005):14‐yearincidence,
progression,andvisualmorbidityofage‐relatedmaculopathy:theCopenhagenCityEyeStudy.
Ophthalmology112:787‐798.
FerrisFL,3rd,SLFine&LHyman(1984):Age‐relatedmaculardegenerationandblindnessdueto
neovascularmaculopathy.Arch.Ophthalmol.102:1640‐1642.
FolkmanJ&MKlagsbrun(1987):Angiogenicfactors.Science235:442‐447.
FontaineO,SOlivier,DDescovich,GCordahi,EVaucher&MRLesk(2011):Theeffectofintravitreal
injectionofbevacizumabonretinalcirculationinpatientswithneovascularmacular
degeneration.Invest.Ophthalmol.Vis.Sci.52:7400‐7405.
GeirsdottirA,SHHardarson,OBOlafsdottir&EStefansson(2014):Retinaloxygenmetabolismin
exudativeage‐relatedmaculardegeneration.ActaOphthalmol92:27‐33.
GeirsdottirA,OPalsson,SHHardarson,OBOlafsdottir,JVKristjansdottir&EStefansson(2012):
Retinalvesseloxygensaturationinhealthyindividuals.Invest.Ophthalmol.Vis.Sci.53:5433‐
5442.
HeierJS,DMBrown,VChong,JFKorobelnik,PKKaiser,QDNguyen,BKirchhof,AHo,YOgura,GD
Yancopoulos,NStahl,RVitti,AJBerliner,YSoo,MAnderesi,GGroetzbach,BSommerauer,R
Sandbrink,CSimader,USchmidt‐Erfurth,View&VSGroups(2012):Intravitrealaflibercept
(VEGFtrap‐eye)inwetage‐relatedmaculardegeneration.Ophthalmology119:2537‐2548.
HoegTB,CEllervik,HBuch,MLaCour,KKlemp,JKvetny,DErngaard&BMoldow(2016):Danish
RuralEyeStudy:EpidemiologyofAdultVisualImpairment.OphthalmicEpidemiol.23:53‐62.
KurtMM,OCekic,CAkpolat,MAslankurt&MNElcioglu(2017):ComparativeRetinalVesselSize
StudyofIntravitrealRanibizumabandBevacizumabinEyeswithNeovascularAge‐Related
MacularDegeneration.Ophthalmologica.238:147‐153.
11
MendrinosE,GMangioris,DNPapadopoulou,GDonati&CJPournaras(2013):Long‐termresultsof
theeffectofintravitrealranibizumabontheretinalarteriolardiameterinpatientswith
neovascularage‐relatedmaculardegeneration.ActaOphthalmol91:e184‐190.
MicieliJA,ETsui,WCLam,MHBrent,RGDevenyi&CHudson(2012):Retinalbloodflowinresponse
toanintravitrealinjectionofranibizumabforneovascularage‐relatedmaculardegeneration.
ActaOphthalmol90:e13‐20.
NgEW&APAdamis(2005):Targetingangiogenesis,theunderlyingdisorderinneovascularage‐
relatedmaculardegeneration.Can.J.Ophthalmol.40:352‐368.
PapadopoulouDN,EMendrinos,GMangioris,GDonati&CJPournaras(2009):Intravitreal
ranibizumabmayinduceretinalarteriolarvasoconstrictioninpatientswithneovascularage‐
relatedmaculardegeneration.Ophthalmology116:1755‐1761.
PekelG,SAcer,ENCetin,RYagci,AKasikci&ACevik(2015):Ocularpulseamplitudeandretinal
vesselcaliberchangesafterintravitrealranibizumab.Int.Ophthalmol.35:657‐662.
RilvenS,TLTorp&JGrauslund(2017):Retinaloximetryinpatientswithischaemicretinaldiseases.
ActaOphthalmol95:119‐127.
RosenfeldPJ,DMBrown,JSHeier,DSBoyer,PKKaiser,CYChung&RYKim(2006):Ranibizumabfor
neovascularage‐relatedmaculardegeneration.N.Engl.J.Med.355:1419‐1431.
StefanssonE,AGeirsdottir&HSigurdsson(2011):Metabolicphysiologyinagerelatedmacular
degeneration.Progressinretinalandeyeresearch30:72‐80.
TatlipinarS,UADinc,NMYenerel&EGorgun(2012):Short‐termeffectsofasingleintravitreal
bevacizumabinjectiononretinalvesselcalibre.Clin.Exp.Optom.95:94‐98.
TetikogluM,MMKurt,HMSagdik,SAktas,MAYildirim&FOzcura(2017):RetrospectiveAnalysisof
theEffectofAfliberceptLoadingDoseontheRetinalVesselDiametersinPatientswith
Treatment‐NaiveNeovascularAMD.Cutan.Ocul.Toxicol.:1‐18.
WickremasingheSS,LBusija,RHGuymer,TYWong&SQureshi(2012):Retinalvenularcaliber
predictsvisualoutcomeafterintravitrealranibizumabinjectiontreatmentsforneovascular
AMD.Invest.Ophthalmol.Vis.Sci.53:37‐41.
12
Figurelegends
Figure1:
A:OpticdisccentredimagetakenbyOxymapT1ofthelefteye(withoutoverlayingcolour‐grid). B:
Sameopticdisccentredpictureas(A)butwithoverlayingcolour‐grid.Thehighlightedpartoftheretinal
vesselsbetweenthetwocirclesisusedformeasurementofretinaloxygensaturationandcalibre.The
oxygenation‐colour‐scaleisshowntotheright.
Figure2:
Flowchart showing the included eyes divided in the three groups (neovascular age‐relatedmacular
degeneration(AMD),dryAMDandnormaleyes).
13
Table1
Comparisonofthethreegroupsatbaseline.
nAMD
Median±IQR
DryAMD
Median±IQR
Normaleyes
Median±IQR
Pvalue
Eyes,n 76 30 43
Age,years 79.0±12.5 77.0±9.0 71.0±9.0** <0.01*
Sex(men),% 38.2 43.3 34.9 0.77
Smokers,% 32.0 14.3 35.7 0.17
Diabetes,% 12.0 10.7 14.6 0.94
BCVA,ETDRSletters 61.0±32.5** 75.0±22.0 75.0±15.0 <0.01*
IOP,mmHg 15.0±6.0 16.0±6.0 15.0±4.0 0.50
Retinalvasculararteriolar
saturation,%94.3±5.2 95.2±5.5 92.6±5.8** 0.04*
Retinalvascularvenular
saturation%60.4±13.6 62.0±15.1 58.3±10.5 0.28
Retinalvasculararteriolar
calibre,μm114.6±17.0 111.1±18.0 113.5±16.0 0.20
Retinalvascularvenular
calibre,μm151.9±22.8 151.9±25.0 155.0±29.5 0.21
ContinuousdataarecalculatedusingKruskal‐Wallisequalityofpopulationsranktestandpresentedas
median and interquartile range (IQR). Categorical data are calculated using chi‐squared test and
presentedaspercentage.Forstatisticallysignificantpvalues,**marksthegroupthat isstatistically
differentfromthetwoothergroups(calculatedusingWilcoxonrank‐sumtest).*p<0.05
nAMD:neovascularage‐relatedmaculardegeneration.BCVA:Best‐correctedvisualacuity.ETDRS:
EarlyTreatmentDiabeticRetinopathyStudy.IOP:intraocularpressure.
14
Table2
Characteristicsofpatientswithtreatment‐naïveneovascularage‐relatedmaculardegenerationasstratifiedbyinitialfunctionalandstructuralresponseto
loadingwiththreemonthlyinjectionswithintravitrealaflibercept.
Functionalresponse Structuralresponse
Yes
Median±IQR
No
Median±IQRPvalue
Yes
Median±IQR
No
Median±IQR Pvalue
Baseline
Eyes,n 39 18 12 45
Age,years 79.0±11.0 81.5±14.0 0.40 78.0±7.5 8.1±13.0 0.79
Sex(men),% 46.2 27.8 0.18 50.0 37.8 0.44
Smoking(smokers),% 30.8 22.2 0.60 25.0 28.9 0.83
Diabetes(diabetes),% 16.7 2.6 0.48 25.0 6.6 0.16
Cataractsurgery(former),% 64.1 50.0 0.31 41.7 64.4 0.15
TypeofCNV(classic/occult/other),% 38.5/61.5/0.0 44.4/55.6/0.0 0.66 25.0/75.0/0.0 44.4/55.6/0.0 0.22
BCVA,ETDRSletters 60.0±31.0 67.5±23.0 0.91 66.5±25.0 64.0±29.0 0.75
IOP,mmHg 15.0±6.0 15.5±7.0 0.65 15.0±4.0 15.0±7.0 0.43
Centralretinalthickness,μm 284.0±97.0 277.0±145.0 0.91 293.0±101.0 230.0±44.5 <0.01*
Follow‐up
Timefromlastinjectiontofollow‐up,
days37.0±12.0 35.5±13.0 0.16 40.0±14.0 36.0±13.0 0.20
BCVA,ETDRSletters 70.0±24.0 56.5±23.0 0.02* 67.5±20.5 65.0±33.0 0.71
Centralretinalthickness,μm 237.0±55.0 226.0±61.0 0.20 232.0±57.0 249.0±62.0 0.19
StructuralandfunctionalresponsedefinedaccordingtochangeinBCVAandretinalmacularthicknessbetweenbaselineandfollow‐up.Atfollow‐uppatients
withapositivestructuralandfunctionalresponsehadnolossinBCVAandthinnerretinalmacularthickness,respectively.Continuousdataarecalculatedusing
15
Wilcoxonrank‐sumandarepresentedasmedianandinterquartilerange(IQE).Categoricaldataarecalculatedusingchi‐squaredtestandarepresentedas
percentage. CNV: Choroidal neovascularization. BCVA:Best‐corrected visual acuity. ETDRS: Early TreatmentDiabeticRetinopathy Study. IOP: intraocular
pressure.*p<0.05
16
Table3
Retinalmetabolicandstructuralmeasurementsasstratifiedbyinitialfunctionalandstructuralresponseto
intravitrealafliberceptloadinginpatientswithtreatment‐naïveneovascularage‐relatedmaculardegeneration.
nBaseline
Median±
IQR
Follow‐up
Median±
IQR
Difference
Median±
IQR
Baselineto
follow‐up,
paired
Pvalue
Functionalresponse
Retinal
arteriolar
saturation,%
Responders 39 94.3±5.4 95.0±4.4 0.8±1.8 0.05
Non‐responders 18 94.7±4.1 95.2±3.6 0.3±2.8 0.39
Pvalue 0.93 0.98 0.70
Retinalvenular
saturation,%
Responders 39 61.5±12.8 63.5±12.1 1.4±6.7 0.37
Non‐responders 18 59.5±17.0 60.0±17.5 0.3±6.0 0.14
Pvalue 0.71 0.55 0.82
Retinal
arteriolar
calibre,μm
Responders 39 115.3±15.0 110.5±12.3 ‐1.3±7.3 0.05
Non‐responders 18 118.6±20.5 118.5±24.5 ‐1.9±4.3 0.19
Pvalue 0.63 0.28 0.69
Retinalvenular
calibre,μm
Responders 39 152.0±22.8 149.8±21.9 1.0±9.3 0.34
Non‐responders 18 155.3±16.8 155.5±22.0 ‐1.0±9.3 0.98
Pvalue 0.63 0.51 0.59
Structuralresponse
Retinal
arteriolar
saturation,%
Responders 12 95.2±4.9 95.0±4.9 0.5±1.7 0.23
Non‐responders 45 93.3±3.3 95.3±2.8 1.6±2.3 0.03*
Pvalue 0.14 0.86 0.03*
Retinalvenular
saturation,%
Responders 12 61.7±14.9 62.0±14.3 0.1±5.3 0.50
Non‐responders 45 59.4±11.1 64.7±6.5 3.9±7.9 0.02*
Pvalue 0.55 0.53 0.03*
Retinal
arteriolar
calibre,μm
Responders 12 118.0±14.5 114.3±14.5 ‐1.3±5.0 0.01*
Non‐responders 45 111.8±12.6 111.0±12.6 ‐1.0±6.9 0.45
Pvalue 0.39 0.52 0.68
17
Retinalvenular
calibre,μm
Responders 12 152.0±18.8 152.0±19.0 1.0±7.5 0.27
Non‐responders 45 156.2±25.1 147.3±23.7 ‐1.5±12.6 0.78
Pvalue 0.72 0.68 0.40
Functionalandstructuralresponsedefinedaccordingtochangeinbest‐correctedvisualacuity(BCVA)andretinal
macularthicknessbetweenbaselineandfollow‐up.Atfollow‐uppatientswithapositivestructuralandfunctional
response had no loss in BCVA and thinner retinal macular thickness, respectively. Data is calculated using
Wilcoxonrank‐sumtest.Thepvalueforthechangesfrombaselinetofollow‐upforbothgroupswascalculated
usingWilcoxonsigned‐ranktest (paireddata).Dataarepresentedasmedianwith interquartilerange(IQR). *
p<0.05
18
Table4
Multiplelogisticregressionmodelindicatingoddsratios(ORs)and95%confidenceintervals(CIs)of
structuralandfunctionaltreatmentresponseafterintravitrealafliberceptloadingintreatment‐naïve
neovascularage‐relatedmaculardegenerationaccordingtoretinalvascularoxygensaturationand
calibre.
OR(95%CI) Pvalue
Functionalresponse
Retinalarteriolaroxygen
saturation,%
Baseline 1.03(0.87‐1.22) 0.69
Follow‐up 1.06(0.91‐1.23) 0.43
Difference 1.08(0.86‐1.34) 0.50
Retinalvenularoxygen
saturation,%
Baseline 1.04(0.95‐1.13) 0.34
Follow‐up 1.05(0.97‐1.13) 0.19
Difference 1.05(0.93‐1.18) 0.44
Retinalarteriolarcalibre,
μm
Baseline 0.98(0.92‐1.02) 0.36
Follow‐up 0.97(0.92‐1.02) 0.24
Difference 0.97(0.86‐1.09) 0.67
Retinalvenularcalibre,μm
Baseline 0.97(0.93‐1.01) 0.16
Follow‐up 0.98(0.94‐1.01) 0.22
Difference 1.01(0.97‐1.84) 0.07
Structuralresponse
Retinalarteriolaroxygen
saturation,%
Baseline 0.91(0.75‐1.08) 0.28
Follow‐up 1.02(0.86‐1.20) 0.85
Difference 1.34(0.97‐1.84) 0.07
Retinalvenularoxygen
saturation,%
Baseline 0.98(0.90‐1.07) 0.65
Follow‐up 1.05(0.95‐1.16) 0.28
Difference 1.17(1.01‐1.36) 0.03*
Retinalarteriolarcalibre,
μm
Baseline 0.98(0.92‐1.03) 0.39
Follow‐up 0.98(0.91‐1.04) 0.44
19
Difference 1.02(0.90‐1.16) 0.74
Retinalvenularcalibre,μm
Baseline 0.99(0.95‐1.03) 0.70
Follow‐up 0.99(0.95‐1.03) 0.49
Difference 0.95(0.86‐1.06) 0.38
StructuralandfunctionalresponsedefinedaccordingtochangeinBCVA(bestcorrectedvisualacuity)
andretinalmacular thicknessbetweenbaselineand follow‐up.At follow‐uppatientswithapositive
structuraland functionalresponsehadno loss inBCVAand thinnermacular thickness,respectively.
Dataiscalculatedusingmultiplelogisticregressionanalysis,adjustedforage,sex,smoking,diabetes
andtimebetweenlastinjectionandfollow‐up.*p<0.05
20
Figure1
(A)
(B)
21
Figure2
nAMD
76eyes
nAMDfollow‐up
57eyes
Functionalresponse
57eyes
Responders
39eyes
slet
Non‐responders
18eyes
Structuralresponse
57eyes
Responders
12eyes
Non‐responders
45eyes
Notreatment
10eyesslet
Nofollow‐up
5eyesslet
Retinalimagingnotpossible
2eyes
Slet
Lessthan3injections
2eyes
DryAMD
30eyes
Normal
43eyes
Top Related