The ophthalmic branch of the Gutenberg Health Study: study design, cohort profile and self

16 Pages·2015·0.6 MB·English

The ophthalmic branch of the Gutenberg Health Study: study design,
cohort profile and self-reported diseases
Höhn, R., Kottler, U., Peto, T., Blettner, M., Münzel, T., Blankenberg, S., Lackner, K. J., Beutel, M., Wild, P. S., &
Pfeiffer, N. (2015). The ophthalmic branch of the Gutenberg Health Study: study design, cohort profile and self-
reported diseases. PLoS ONE, 10(3), [e0120476]. https://doi.org/10.1371/ journal.pone.0120476
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RESEARCHARTICLE
The Ophthalmic Branch of the Gutenberg
Health Study: Study Design, Cohort Profile
and Self-Reported Diseases
RenéHöhn1,2*,UlrikeKottler1,TundePeto3,MariaBlettner4,ThomasMünzel5,
StefanBlankenberg6,KarlJ.Lackner7,ManfredBeutel8,PhilippS.Wild5,9,10☯,
NorbertPfeiffer1☯
1 DepartmentofOphthalmology,UniversityMedicalCenterMainz,Mainz,Germany,2 KlinikPallas,Olten,
Switzerland,3 NIHRBiomedicalResearchCenteratMoorfieldsEyeHospital,NHSFoundationTrust,and
a11111 UCLInstituteofOphthalmology,London,UnitedKingdom,4 InstituteforMedicalBiostatistics,Epidemiology
andInformatics,UniversityMedicalCenterMainz,Mainz,Germany,5 PreventiveCardiologyandPreventive
Medicine/DepartmentofMedicine2,UniversityMedicalCenterMainz,Mainz,Germany,6 ClinicforGeneral
andInterventionalCardiology,UniversityMedicalCenterHamburg-Eppendorf,Hamburg,Germany,
7 InstituteforClinicalChemistryandLaboratoryMedicine,UniversityMedicalCenterMainz,Mainz,
Germany,8 DepartmentofPsychosomaticMedicineandPsychotherapy,UniversityMedicalCenterMainz,
Mainz,Germany,9 CenterforThrombosisandHemostasis,UniversityMedicalCenterMainz,Mainz,
Germany,10 GermanCenterforCardiovascularResearch(DZHK),partnersiteRhine-Main,Mainz,
Germany
OPENACCESS
☯Theseauthorscontributedequallytothiswork.
Citation:HöhnR,KottlerU,PetoT,BlettnerM,
* [email protected]
MünzelT,BlankenbergS,etal.(2015)The
OphthalmicBranchoftheGutenbergHealthStudy:
StudyDesign,CohortProfileandSelf-Reported
Diseases.PLoSONE10(3):e0120476.doi:10.1371/ Abstract
journal.pone.0120476
AcademicEditor:JamesT.Rosenbaum,Oregon Purpose
Health&ScienceUniversity,UNITEDSTATES
Thispaperdescribesthestudydesign,methodology,cohortprofileandself-reporteddis-
Received:September15,2014 easesintheophthalmologicalbranchoftheGutenbergHealthStudy(GHS).
Accepted:January22,2015
Methods
Published:March16,2015
TheGHSisanongoing,prospective,interdisciplinary,single-center,population-basedco-
Copyright:©2015Höhnetal.Thisisanopen
accessarticledistributedunderthetermsofthe hortstudyinGermany.Themaingoalsoftheophthalmologicalsectionaretoassessthe
CreativeCommonsAttributionLicense,whichpermits prevalenceandincidenceofoculardiseasesandtoexploreriskfactors,geneticdetermi-
unrestricteduse,distribution,andreproductioninany
nantsandassociationswithsystemicdiseasesandconditions.Theeyeexaminationat
medium,providedtheoriginalauthorandsourceare
baselineincludedamedicalhistory,self-reportedeyediseases,visualacuity,refractiveer-
credited.
rors,intraocularpressure,visualfield,pachymetry,keratometry,fundusphotographyand
DataAvailabilityStatement:Theanalysispresents
tearsampling.The5-yearfollow-upvisitadditionallyencompassedopticalcoherenceto-
clinicaldataofalarge-scalepopulation-basedcohort
withongoingfollow-upexaminations.Thisproject mography,anteriorsegmentimagingandopticalbiometry.Thegeneralexaminationinclud-
constitutesamajorscientificeffortwithhigh edanthropometry;bloodpressuremeasurement;carotidarteryultrasound;
methodologicalstandardsanddetailedguidelinesfor
electrocardiogram;echocardiography;spirometry;cognitivetests;questionnaires;assess-
analysisandpublicationtoensurescientificanalyses
mentofmentalconditions;andDNA,RNA,bloodandurinesampling.
onhighestlevel.Therefore,dataarenotmade
availableforthescientificcommunityoutsidethe
establishedandcontrolledworkflowsandalgorithms. Results
Tomeetthegeneralideaofverificationand
Of15,010participants(aged35-74yearsatthetimeofinclusion),oculardataareavailable
reproducibilityofscientificfindings,weofferaccessto
dataatthelocaldatabaseinaccordancewiththe for14,700subjects(97.9%).Themeanvisualacuity(standarddeviation),meanspherical
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 1/15
GutenbergHealthStudyandOphthalmicStudyDesign
ethicsvoteuponrequestatanytime.TheGHS equivalent,mediandecimalvisualacuity,andmeanintraocularpressurewere0.08(0.17)
steeringcommittee,whichcomprisesamemberof logMar,-0.42(2.43)diopters,0.9and14.24(2.79)mmHg,respectively.Thefrequenciesof
eachinvolveddepartmentandtheheadofthe
self-reportedstrabismus,glaucoma,surgeryforretinaldetachmentandretinalvascularoc-
GutenbergHealthStudy(PSW),convenesoncea
month.Thesteeringcommitteedecidesoninternal clusionswere2.7%,2.3%,0.2%and0.4%,respectively.
andexternalaccessofresearchersanduseofthe
dataandbiomaterialsbasedonaresearchproposal
tobesuppliedbytheresearcher.Interested
Conclusions
researchersmaketheirrequests
totheheadoftheGutenbergHealthStudy(PhilippS.
TheGHSisthemostextensivedatasetofophthalmicdiseasesandconditionsandtheirrisk
Wild; [email protected]).More
factorsinGermanyandoneofthelargestcohortsworldwide.Thisdatasetwillprovidenew
detailedcontactinformationisavailableatthe
homepagesoftheGHS(www.gutenberghealthstudy. insightintheepidemiologyofophthalmicdiseasesandrelatedmedicalspecialties.
org)ortheophthalmicbranchoftheGHS(www.
unimedizin-mainz.de/augenklinik/startseite/ghs.html).
Funding:TheGutenbergHealthStudyisfunded
throughthegovernmentofRheinland-Pfalz(“Stiftung
Rheinland-PfalzfürInnovation”,contractAZ961-
386261/733),theresearchprograms“Wissenschafft
Zukunft”and“CenterforTranslationalVascular Introduction
Biology(CTVB)”oftheJohannesGutenberg-
Severalepidemiologicalstudieshavereportedtheprevalence,incidenceandriskfactorsof
UniversityofMainz,anditscontractwithBoehringer
majorophthalmicdiseases.However,theremaybelargedifferencesbetweenpopulationsand
Ingelheim,PHILIPSMedicalSystemsandNovartis
Pharma,includinganunrestrictedgrantforthe evenwithinthesamepopulationatdifferentpointsintime[1].Thisvariabilitymightbedueto
GutenbergHealthStudy.PSWisfundedbythe demographicdifferencesorgeneticandenvironmentalfactors,oritmightbepartlyexplained
FederalMinistryofEducationandResearch(BMBF bymethodologicaldifferences[2,3].
01EO1003).TPwassupportedbytheNIHR
Knowledgeofthepreciseepidemiologicalfeaturesofapopulationisessentialforplanning
BiomedicalResearchCenteratMoorfieldsEye
thefutureuseofmedicalresources[4].Aspopulationageandenvironmentalriskfactors
HospitalNHSFoundationTrustandtheUCLInstitute
change,thoroughepidemiologicalresearchisnecessarytoacquiretheknowledgetoensuresuf-
ofOphthalmology.Funderswereinvolvedinthe
developmentofthestudydesignasscientific ficientmedicalcare,publichealthscreeningsandtheefficientuseofmedicalresources.
consultants.However,theyplayednoroleindata Severalmajorophthalmologicaldiseasesarelinkedtosystemicdiseasessuchasatheroscle-
collection,analysis,decisiontopublish,or rosis,diabetesmellitusorarterialhypertension.Changesintheprevalence,incidenceandtreat-
preparationofthemanuscript.KlinikPallasprovided
mentofthosesystemicriskfactorswillchangetheoccurrenceandcourseoftheassociated
supportintheformofasalaryforauthorRH,butdid
ophthalmologicaldiseases.Furthermore,thereiseminentneedtoinvestigatetheassociation
nothaveanyadditionalroleinthestudydesign,data
collectionandanalysis,decisiontopublish,or betweeneyediseasesandrelatedcardiovascular,neurodegenerative,metabolicand
preparationofthemanuscript.Thespecificrolesof immunologicalconditions.
theauthorsarearticulatedintheauthorcontributions TheophthalmologicalbranchoftheGutenbergHealthStudy(GHS)wasdesignedandes-
section.
tablishedto
CompetingInterests:BoehringerIngelheim,
a. estimatetheprevalenceandincidenceofmajoroculardiseases(suchasglaucoma,age-related
PHILIPSMedicalSystemsandNovartisPharma
maculardegeneration,diabeticretinopathy)andtheirriskfactorsinGermany,whichisthe
providedfundingtowardsthisstudy.RHisan
employeeofKlinikPallas,Switzerland.Thereareno Europeancountrywiththelargestpopulation,
patents,productsindevelopmentormarketed
b. reportdistributiononbiometricocularparameterswithinapopulation-basedstudydesign,
productstodeclare.Thisdoesnotaltertheauthors'
adherencetoallthePLOSONEpoliciesonsharing
c. providedataonassociationsbetweenocularparameters(e.g.intraocularpressure,refractive
dataandmaterials.
error,centralretinalthickness)anddiseases(e.g.diabeticretinopathy,age-relatedmacular
degeneration,glaucoma)withinparticularcardiovascularparametersanddiseases,genetic
variants,mentalandgeneralconditions,
d. establishalargebiobankforfutureresearchprojects.
ThisarticledescribesthestudystructureandmethodsoftheophthalmicbranchoftheGHS,
presentsitsothermajorpartsandresearchtopicsandprovidesdataonthecohortprofileand
self-reportedoculardiseases.
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 2/15
GutenbergHealthStudyandOphthalmicStudyDesign
MaterialsandMethods
TheGutenbergHealthStudy(GHS)isanongoingpopulation-based,interdisciplinary,pro-
spective,single-centercohortstudyatthemedicalcenterofJohannesGutenbergUniversity
MainzinGermany.Allparticipantsprovidedinformedconsent.Thestudydesignfollowedthe
tenetsoftheDeclarationofHelsinki.TheGHSwasapprovedbythelocalethicscommittee
(EthicsCommissionoftheStateChamberofPhysiciansofRhineland-Palatinate)andbythe
localandfederaldatasafetycommissioners.
Studyaim
TheGHSaimstoassesstheprevalenceandincidenceofcardiovascular,metabolic,ophthalmo-
logicalandmentaldisordersinthepopulationofthecityofMainzandtheMainz-Bingendis-
trictinthemid-westernpartofGermany(Rhine-Mainregion).Theprimarygoalofthestudy
istoimprovethepredictionofdiseasebytakingintoaccountpsychosocial,environmentaland
lifestyleriskfactors,subclinicaldisease,proteinpatternandgeneticvariants.Thesamplesize
calculationwasbasedontheprimaryendpointsofthestudy,myocardialinfarctionand
cardiovasculardeath.
Studydesign
Apilotstudyoffeasibilityandforestablishingprocesssequenceswasconductedbetween2005
and2007.Thebaselineassessmentofthepopulation-basedcohortof15,010menandwomen
aged35to74atthetimeofinclusionstartedinApril2007andwascompletedinMarch2012.
Aninterdisciplinaryexaminationprotocolwasapplied,includinggeneral,anthropometric,car-
diovascular,psychologicalandophthalmologicaltestslasting5hours.Acomputer-assistedin-
terviewandquestionnaireselucidatedtheclassicpsychosocial,environmental,physicalactivity,
nutritionalandlifestyleriskfactors.Twoandahalfyearsafterthebaselineexamination,thepar-
ticipantswerecontactedforafollow-upinvestigationbycomputer-assistedtelephoneinterview,
whichrecordedtheend-points,medicalhistoryandself-reportedmedicationandlifestylefac-
tors.Fiveyearsafterthebaselinevisit,theparticipantsareinvitedtothestudycenterforafol-
low-upvisit,comprisingofrepeatedmeasurementswithanextendedexaminationprotocol
lastingnearly6hours.Asecondtelephoneinterviewwilltakeplace7.5yearsafterthebaseline
visit.Furthermore,a10-yearfollow-upofthewholecohortisplannedcommencingin2017.
Studypopulation
OutofallresidentsofthecityofMainz(n=196,425)andthedistrictofMainz-Bingen
(n=201,371)210,867subjectsaged35to74yearsatthetimeofinclusionwereeligibletopar-
ticipateintheGHS.Ofthese,asampleof35,008subjects,stratifiedbygender,decadeofage
andresidence(ruralvs.urban),wasselectedviathelocalresidents’registrationoffices.Astudy
sampleofintended15,000participantswasdrawninwavesofequalstratificationtomeeta
standardizedrecruitingandtoallowdefinedsubsampleanalysesafterinclusionof5,000and
10,000subjects.TheexclusioncriteriawereinsufficientknowledgeoftheGermanlanguage
andphysicalormentalinabilitytoparticipateintheexaminationsatthestudycenter.Atotal
of15,010subjectswereenrolledinthestudysampleandtheoverallresponseratewas60.3%.
Enrollmentmethods
Thestudyparticipantswereselectedrandomlyfromlocalresidents’registrationoffices.Accord-
ingtoGermanlaw,itismandatoryforeachindividualtoregisterhis/herpersonalandresidential
datawithinaweekaftermovingtoorfromanylocationwithinGermany.Selectedparticipants
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 3/15
GutenbergHealthStudyandOphthalmicStudyDesign
Table1. Summaryofnon-ophthalmologicaltests,questionnairesandinterviewsoftheGutenberg
HealthStudy(baselineexamination).
Generaldata Anthropometry
Bodytemperature
Currentweatherdata
Physicalactivity
Nutrition
Medications
Cardiology,angiologyand Electrocardiography
pulmonologytests
Echocardiography
Bloodpressureandpulse
Sonographyofneckvessels
Neurocardiacregulation
Occlusionpressuremeasurementandanklebrachialindex
Spirometry
Flow-mediatedvasodilationandarterialstiffness,volume
plethysmographyoffingerartery,digitalphotoplethysmographical
pulsecurveanalysis
Carbonmonoxideinalveolarair
Laboratorytests Bloodcount,electrolytes,renalandliverfunctionparameters,blood
fatparameters
Basicandspecialbloodcoagulationparameters,cardiacenzymes
Inflammatoryparameters,selectedvitaminsandhormones
Parametersofoxidativestress,basicurinetests
Psychologicalandsocialdata Socialdemographicdata
Accesstoanduseofmedicalcare
Cancerprevention
Gender-relatedquestions
Fullmedicalhistory
Classiccardiovascularriskfactors
Disease-relatedcomplaintsandpathologies
Familymedicalhistory
Children
Healthcarebehavior
Hobbies
Smoking,passivesmoking,alcoholconsumption
Occupationalhistory
Exposuretoairbornepollutantsandnoise
Generalhappinessandenvironmentalfactors
Domesticenvironment
Neurocognitivefunction
Personality,psychiatricdiseasesandmentaldisorders
Everydayduties
Socialintegration
Psycho-socialstressatwork
Lifeevents
Visualqualityoflife
Biomaterials Plasma,serum,DNA,RNA,urine,gingivalsulcusswab,lacrimalfluid
doi:10.1371/journal.pone.0120476.t001
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 4/15
GutenbergHealthStudyandOphthalmicStudyDesign
werecontactedbyletterandinvitedforthebaselineexamination.Iftheydidnotrespond,then
therecruitmentteamcontactedthembyphone.Persons,whowereunabletocometothestudy
centerordidnotwanttoparticipate,wereaskedtorespondtosomequestionsaboutdemo-
graphicsandtheirreasonsfornon-participation(non-responderquestionnaire).Astagedcon-
sentprocesswasestablishedfornon-invasivetesting,bloodsamplingandgeneticassessments.
Theparticipantscouldwithdrawfromthestudyatanypointwithoutaneedforjustification.
Consentingwithdrawalimmediatelyresultedindisposalofallbio-samples.
Datamanagement/Steeringcommittee
Thedatawerecollected,managedandanalyzedatacentraldatabankunderthesupervision
andresponsibilityoftheGHSstudycoordinator.Plausibilitychecksanddataqualitycontrols
wereperformedonaregularbasis.TheGHSsteeringcommitteedecidedontheinternaland
externalaccessanduseofthedataandbiomaterials.
Generalandnon-ophthalmologicaltests
Alldataacquisitionandtestswereperformedinastandardizedmannerbytrainedandcertified
personnelattheGHSstudycenter.Thesequenceofexaminationsandinterviewswaspredeter-
mined.Table1givesanoverviewofnon-ophthalmologicaltests,questionnairesandinterviews.
Ophthalmologicalexaminations
Table2summarizestheophthalmologicalexaminationsoftheGHS,whichlasted25minutes
perparticipantandwereperformedbetween11a.m.and8p.m.Duringthebaselinevisitall
Table2. GutenbergHealthStudyeyeexaminationsatbaseline(2007–2012)andatthe5-yearfollow-
up(2012–2017).
Manufacturer/Methods/Specifications
Baseline Follow-up
Autorefraction HumphreyAutomatedRefractor/Keratometer
Correctedvisualacuity (HARK)5991
Pachy-andkeratometry Pachycam2 Pentacam2
Visualfieldscreening FDTHumphreyMatrixPerimeter1
Intraocularpressure NidekNT-2000Noncontacttonometer3
Biometry - LenstarLS9004
Slit-lampexamination Haag-StreitBM9004 -
Fundusphotography VisucamPRONM,145°fieldfundus,30°field
opticdiscandmaculararea
OpticalCoherenceTomography Spectralis-OCT5,6 Spectralis-OCT5
SchirmerIITearTest7/collectionoftearfluid Oxybuprocaine-hydrochloride0,4%eyedrop8,
SchirmerTearTestOphthalmicStrips9
1CarlZeissMeditecAG,Jena,Germany
2Oculus,Wetzlar,Germany
3NidekCo.,Japan
4HaagStreit,Koeniz,Switzerland
5HeidelbergEngineering,Heidelberg,Germany
6partoftheexaminationsince2011
7performedonlyatbaselinevisit
8OmniVision,Puchheim,Germany
9OptitechEyecare,Allahabad,India,
doi:10.1371/journal.pone.0120476.t002
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 5/15
GutenbergHealthStudyandOphthalmicStudyDesign
investigationswereperformedbyaboard-certifiedophthalmologist.Startingwiththe5-year
follow-upinApril2012,allexaminationswerebeingperformedbywell-trainedandcertified
studyassistants.Thestudyprotocolwasmodifiedwiththefollow-upphase;allchangesare
showninTable2.
RefractionandVisualacuity. Autorefractionandcorrectedvisualacuityweremeasured
usingaHumphreyAutomatedRefractor/Keratometer(HARK)599(CarlZeissAG,Jena,Ger-
many).Therighteyewasmeasuredfirst.Afterobtainingautorefraction,correctedvisualacuity
wasrecordedusingthebuilt-inSnellencharts,rangingfrom20/400to40/20(decimal0.05to
2.0).Ifthevisualacuitywasbelow20/400(decimal0.05),furthertestingwasperformedusinga
visualacuitychartatadistanceofonemeterupto20/800,andfurtherdowntocountingfin-
gers,handmovements,lightperceptionandnolightperceptionatthelowestlevel.Thespheri-
calequivalentwascalculatedasthesphericalcorrectionvalueplushalfthecylindricalpower.
Intraocularpressure. Intraocularpressurewasmeasuredwithanoncontacttonometer
andautomaticair-puffcontrol(NidekNT-2000;Nidek,Co.,Gamagori,Japan).Alwaysstarting
withtherighteye,themeanofthreemeasurementswithina3-mmHgrangewasobtainedfor
eacheye.
Visualfieldtesting. Frequencydoublingtechnology(FDT)HumphreyMatrixPerimeter
wasusedforvisualfieldtesting(programN-30-5).Theparticipantswereaskedwhetherthey
hadanyexperiencewithvisualfieldtesting(yes/no)andstartedthetestwiththeirrighteye,
whilethosewithanoddstudyIDnumberstartedwiththelefteye.Toallowtheparticipantto
relax,themeasurementofcornealthickness(describedbelow)wasperformedinbetweenthe
visualfieldtestingofthefirstandthesecondeye.Subjectswitharefractiveerrorbetween+5.0
and-5.0diopterssphericalequivalentunderwenttheexaminationwithoutcorrection;subjects
witharefractiveerrorhigherorlowerthan+5.0or-5.0diopterssphericalequivalentusedtheir
correctivedevices(glassesorcontactlenses).Ifdefectswithathresholdofeitheroneabnormal
cluster/fieldwithP<1%ortwoadjacentclusters/fieldswithP<5%becameapparent,theexam-
inationwasimmediatelyrepeatedfortheaffectedeye.Theexaminationresultwaspromptly
classifiedasa)normalorb)conspicuous.
Pachymetry/Keratometry. Anoncontact,Scheimpflug-basedopticaldevice(Pachycam,
Oculus,Wetzlar,Germany)wasusedtomeasurethecornealthicknessandcurvatureduring
thebaselineexaminationofallparticipants.Onlymeasurementswithaqualityscoreabove
90%wereaccepted.PachymetryisbasedonScheimpflugimagesofahorizontal4-mmsection
andrevealsthecentralandthinnestcornealthicknesses.ThePachycamhasanintegratedker-
atometerthatmeasuresthecentralK-valueaswellastheK-valuesinthecentral30°.Beginning
withthe5-yearfollow-up,wereplacedthePachycamwiththePentacamHR(Oculus,Wetzlar,
Germany)forcornealthicknessmeasurementsandkeratometry.ThePentacamusesthesame
measurementtechnology,butitprovidesadditionaldataonthearchitectureoftheanterior
segmentoftheeye(seeanteriorsegmenttomography).Allofthesetestsstartedwiththe
righteye.
PRONM
Posteriorsegmentphotography. AVisucam nonmydriaticfunduscamera(Carl
ZeissAG,Jena,Germany)wasusedtotakethreedigitalfunduspicturesthroughanon-
pharmacologicallydilatedpupil.Theparticipantswerepositionedinadarkenedroomtoallow
fornaturalpupildilationinpreparationforposteriorsegmentphotography.Twoimageswere
centeredontheopticdisc(30°and45°field)andoneonthemacula(30°).Wealwaysstarted
withtherighteye.Atbaseline,theophthalmologistconductedasimpleevaluationofthefun-
duspicturesaccordingtotheparameterslistedinTable3.
Slit-lampbiomicroscopyoftheanteriorsegment. Aslit-lampexaminationwasper-
formedwithundilatedpupilsinadarkenedroomtodetectpathologiesoftheanteriorsegment.
Table3providesasummaryofrecordedparametersandconditions.
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 6/15
GutenbergHealthStudyandOphthalmicStudyDesign
Table3. Summaryofrecordedophthalmicparametersintheelectroniccasereportfile(eCRF,base-
lineexamination).
Oculomotoric Eyepositionaccordingtocornealreflexes
characteristics
Heterotropiarelatedtonervepalsy
Eyelid Gradingofblepharitis(normal/mild/moderate/severe)
Lidposition(normal/entropion/ectropion)
Anteriorsegment Conjunctiva(hyperemia,LIPCOF,pinguecula)
Cornea(generalpathologies)
Anteriorchamber(cells,flare)
Iris(color,atrophicareas,pigmentdispersion,rubeosis,synechiae)
Lens(status,cataract,secondarycataract,pseudoexfoliation)
Posteriorsegment Pathologiesingeneral(yes/no)
Coneattheopticdisc(yes/no)
Glaucomatousdiscatrophy(no/suspicious/beginning/advanced)
Otheropticnerveatrophies(yes/no)
Hypertensiveretinopathy(gradingaccordingtoKeith-Wagener-Barker
classification[32])
Maculardrusen(yes/no)
Age-relatedmaculardegeneration(no/dry/geographicatrophy/wet/scar)
Diabeticretinopathy(no/mild/moderate/proliferative)
Retinalveinocclusion(no/branch/hemi-central/central)
Retinalarterialocclusion(no/branch/hemi-central/central)
Retinaldetachment(yes/no)
doi:10.1371/journal.pone.0120476.t003
Anteriorsegmenttomography. Non-contactanteriorsegmenttomographywasintro-
ducedtothestudyprotocolinApril2012asthe5-yearfollow-uptestingcommenced.ThePen-
tacamHR(Oculus,Wetzlar,Germany)usesanautomaticallyrotatingScheimpflugcamerato
measureanteriorsegmentarchitecture,includingtheentirecornea,anteriorchamberandlens.
ThePentacamprovidesdataonthefollowingparameters:centralcornealradii,cornealthick-
nessandasphericity,coloredmapsofcurvatureandelevation,chamberangle,volumeandele-
vation,aswellaslenstransparency.Pharmacologicalpupildilationwasnotapplied.Photo
documentationwasperformedontherighteyefirst.
Ocularbiometry. Non-contactopticalbiometrywasaddedtothestudyprotocolinApril
2012,commencingwiththe5-yearfollow-up.LenstarLS900(Haag-Streit,Koeniz,Switzer-
land)employsopticallow-coherencereflectometrytechnologytocapturetheocularglobe's
axialdimensions.Asinglemeasurementyieldsdataonthefollowingparameters:centralcorne-
althickness,keratometry,white-to-whitecornealdistance,pupildiameter(indarkenedroom),
lensthickness,anteriorchamberdepth,theocularglobe'saxiallength,visualaxiseccentricity
andretinalthickness(distancebetweeninternallimitingmembraneandretinalpigmentepi-
thelium).Therighteyewasmeasuredfirst.
Opticalcoherencetomography(OCT). Spectraldomainopticalcoherencetomography
wasperformedwiththeSPECTRALIS(HeidelbergEngineering,Heidelberg,Germany).The
scansweretakenthroughnon-pharmacologicallydilatedpupilsinthedarkenedexamination
room.Onemacularvolumescan(amodifiedposteriorpolescan)withenhanceddepthimag-
ing(EDI)andtwoopticdiscscans—anopticnerveheadvolumescanwithEDIandaperipapil-
laryretinalnervefiberlayer(RNFL)scan—wereconducted.
Tearsampling/Biobanking. Tearfluidsamplesweretakenfrombotheyesofeachpartic-
ipantusingSchirmer’sTearOphthalmicstrips(OptitechEyecare,Allahabad,India)onemin-
uteafterapplicationoflocalanestheticdropsofOxybuprocaine-hydrochloride0.4%
PLOSONE|DOI:10.1371/journal.pone.0120476 March16,2015 7/15
GutenbergHealthStudyandOphthalmicStudyDesign
(OmniVision,Puchheim,Germany).Thestripswereplacedinthelowerconjunctivalsacfor
threeminutes.Ifthestripbecamesaturatedbeforethescheduledendofthetest,itwasimmedi-
atelyremovedfromtheconjunctivalsac.Atthebaselinevisit,theophthalmologistalsoclassi-
fiedtheamountoffluidintothreecategoriesa)normal,b)slightlyreducedorc)severely
reducedtearproduction.Asallbiomaterials,tearsamplesarestoredat-80°Cintwosegregated
roomsusingastandardizedandpartiallyautomatizedstoringsystem.Thetemperatureis
monitoredelectronically.
VisualFunctioningQuestionnaireandfamilyhistoryofage-relatedmaculardegenera-
tionandglaucoma. TheGermanversionofthe“NationalEyeInstituteVisualFunctioning
Questionnaire25”(NEIVFQ-25)wasused[5].Duringthecomputer-assistedpersonalinter-
view(CAPI),allparticipantswereaskedwhethertheywereawareofanyage-relatedmacular
degenerationorglaucomaintheirfamilyhistory(parentsorsiblings).
Self-reportedeyediseases
Self-reportedeyediseaseswereextractedfromthepatienthistorycollectedalongwiththeeye
examination.Everyparticipantwasaskediftheysufferfromanykindofglaucoma,macular
degenerationoranyothereyedisease.Thediseaseswereclusteredtotheirclinicalandcolloqui-
altermsandanalysedrespectively.
Classificationofmajoreyediseases
Thedefinitionstodetectglaucoma[6],age-relatedmaculardegeneration[7,8]anddiabetic
retinopathy[9]arelistedinTable4.
Geneticanalyses
GenomicDNAextractionwasobtainedfromtwobuffy-coatedEDTAbloodsamplesfrom
eachparticipant.TheDNAwasextractedaccordingtoMiller'smethod[10].DNAsamples
fromthefirst5000GHSparticipantsweregenotypedusingtheAffymetrixGeneChipGe-
nome-WideHumanSNPArray6.0inbatchesof94GHSsamples,includingonereferencege-
nomicDNAbyAffymetrix(Ref.103,50ng/μl)andonenegativecontrolwithoutgenomic
DNAperbatch[11].TotalRNAwasisolatedfrommonocytes(first1700participants)andpe-
ripheralbloodmononuclearcells(allremainingparticipants).RNAwasisolatedonlyforthose
participantspresentingatthestudycenterduringthemorningsession.
RNAwasisolatedwithin24hafterbloodsamplingtoensurerapidsampleprocessing.
Monocyteswereseparatedfromwholeblood,andRNAwaspreparedasdescribedpreviously
[11].TheintegrityoftheentireRNAwasassessedthroughanalysisonanAgilentBioanalyzer
2100(AgilentTechnologies,Böblingen,Germany).SampleswithanRNA-Integritynumber
(RIN)lessthansevenwereexcludedfromfurtheranalyses.
TranscriptomeanalysesofRNAwereperformedfor2200participantsusinganIllumina
Ht-12BeadChipV3(n=1700)andtheAffymetrixGeneChipHumanExon1.0STArray
(n=500)[11,12].Furthergenetictestingwillbepossibleusingthestoredbiosamples.Weplan
Table4. Definitionofglaucoma,age-relatedmaculardegenerationanddiabeticretinopathyintheGu-
tenbergHealthStudy.
Disease Definition
Glaucoma ISGEOglaucomaclassification[6]
Age-relatedMacularDegeneration RotterdamEyeStudyclassification[7,8]
DiabeticRetinopathy EarlyTreatmentDiabeticRetinopathyStudy(ETDRS)[9]
doi:10.1371/journal.pone.0120476.t004
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GutenbergHealthStudyandOphthalmicStudyDesign
tousenext-generationsequencingapproachesforfurthergeneticanalysesoftheDNAand
RNAsamples.Furthermore,sequencingofmiRNAinthetotalRNAsamplesaswellasepige-
neticassessmentswillbeperformed.
Qualityassurance
Allstudy-relatedactivitieswereperformedaccordingto“GoodClinicalPractice”,“GoodEpi-
demiologicalPractice”andthetenetsofthedeclarationofHelsinki.Standardoperatingproce-
dures(SOPs)wereavailableforalltests,andthesequenceofstudy-relatedactivitieswas
predeterminedandisbinding.TheSOPswereverifiedandsetduringthepilotphaseofthe
studyandbetweentheendofthebaselineexaminationandthebeginningofthe5-yearfollow-
up.Acentraldatamanagementteamisinchargeofperformingplausibilitytestsanddescrip-
tivestatisticsonaregularbasis.
Cardiovascularriskfactorassessment
Cardiovascularriskfactors(CVRFs)weredefinedasfollows:Smokingwasdichotomizedinto
non-smokers(neversmokersandex-smokers)andsmokers(occasionalsmokersandsmok-
ers).Arterialhypertensionwasdiagnosedifantihypertensivedrugsweretaken,ifthemeansys-
tolicbloodpressurewas(cid:1)140mmHginthe2ndand3rdstandardizedmeasurementafter8
and11minutesofrestorifthemeandiastolicbloodpressurewas(cid:1)90mmHginthe2ndand
3rdstandardizedmeasurementafter8and11minutesofrest.Diabeteswasstatedforindividu-
als,whoatleastholdoneofthefollowingconditions:(a)definitediagnosisandtreatmentofdi-
abetesbyaphysician,(b)abloodglucoselevel(cid:1)126mg/dlatthebaselineexaminationafter
overnightfastingofatleast8hoursor(c)abloodglucoselevelof(cid:1)200mg/dlatthebaseline
examinationafterafastingperiodofatleast8hours.Obesitywasdeterminedasabodymass
index(BMI)(cid:1)30kg/m².Dyslipidemiawasdefinedasadefinitediagnosisofdyslipidemiabya
physicianoraLDL/HDL-ratioof(cid:1)3.5.Anthropometricmeasurementswereperformedwith
calibrateddigitalscales(Seca862,Seca,HamburgGermany),ameasuringstick(Seca220,Seca,
Hamburg,Germany)andawaist-measuringtape.
Self-reportedcardiovasculardiseases
Self-reportedcardiovasculardiseasedatawerecollectedfromcomputer-assisted
personalinterviews.
Statisticalanalyses
Alldataunderwentqualitycontrolbyacentraldatamanagementteamandwerecheckedfor
completenessandcorrectnessbypredefinedalgorithmsandqualityplausibilitycontrols.Prev-
alences,ratesandmeanvaluesarealwayspresentedforthestudysample(nospecialindication,
onlyintablesindicatedas“unweighted”)andweightedforthelocalpopulationinthecityof
MainzandtheMainz-Bingendistrict(indicatedas“weighted”)becausetheolderagedecade
wasoverrepresentedinourstudysample.Weighteddataarenecessarytoprovidepopulation-
basedresultsandtoachievecomparabilitytootherpopulation-baseddata.
Results
Aftercompletingapre-studyphase,thestudybeganin2007,andthebaselineexaminationwas
completedinMarch2012.The5-yearfollow-upofthecohortstartedinApril2012.TheGHS
cohortcomprisedatotalof15,010participants.
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