Non-viral microbial keratitis in adults: clinical and laboratory aspects

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h tt p : / / w w w . b j m i c r o b i o l . c o m . b r /

Clinical

Microbiology

Non-viral

microbial

keratitis

in

adults:

clinical

and

laboratory

aspects

Eunice

Stella

Jardim

Cury

∗

,

Marilene

Rodrigues

Chang,

Elenir

Rose

Jardim

Cury

Pontes

UniversidadeFederaldoMatoGrossodoSul–UFMS,CampoGrande,MS,Brazil

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t

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c

l

e

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f

o

Articlehistory:

Received23December2017 Accepted10May2018

Availableonline14August2018 AssociateEditor:RosanaPuccia

Keywords: Keratitis Corneaulcer EyeInfections Bacterial EyeInfections Fungal Acanthamoebakeratitis

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Thisstudycomparespatientswithandwithoutnon-viralmicrobialkeratitisinrelationto sociodemographicvariables,clinicalaspects,andinvolvedcausativeagent.Clinicalaspects, etiologyandtherapeuticprocedureswereassessedinpatientswithandwithout kerati-tisthatwerediagnosedinanEyeCareCenterinCampoGrande,MS,Brazil.Patientswere dividedintotwogroups:(a)cases:64patientswithnon-viralmicrobialkeratitisdiagnosedat biomicroscopy;and(b)controls:47patientswithothereyedisordersthatwerenotkeratitis. Laboractivityrelatedtoagriculture,cattleraising,andcontactlensusewerealllinkedto keratitisoccurrence(p<0.005).Inpatientswithkeratitis,themostcommonsymptomswere painandphotophobia,andthemostfrequentlyusedmedicineswerefourth-generation ﬂu-oroquinolones(34.4%),amphotericinB(31.3%),andnatamycin(28.1%).Microbialkeratitis evolvedtocornealperforationin15.6%ofcases;transplantwasindicatedin10.9%ofcases. Regardingtheetiologyofthiscondition,23(42.2%)keratitiscaseswerecausedbybacteria (Pseudomonasaeruginosa,12.5%),17(39.1%)byfungi(Fusariumspp.,14.1%andAspergillusspp., 4.7%),and4(6.3%)byAcanthamoeba.Patientswithkeratitispresentwithapoorer progno-sis.Rapididentiﬁcationoftheetiologicagentisindispensableanddependsonappropriate ophthalmologicalcollectionandmicrobiologicaltechniques.

Introduction

Microbial keratitis is an infectious corneal disease associ-atedwith potential vision impairment and blindness. It is

one of the primary indications for corneal transplants in

Brazilandaroundtheworld.Thewidespreaduseofcontact

∗ _{Corresponding}_author.

E-mail:eunicejcury@gmail.com(E.S.Cury).

lenses,cornealsurfacediseases,trauma,andeyesurgeryhave beendescribedasmajorriskconditionsforitsoccurrence.1–4

Complicationsassociatedwithcontactlenswearhavebeen

observedworldwide,withthehighestincidenceoccurringin developedcountriesandpopulationsofhighersocioeconomic status.5,6

Studieshaveshownthattheetiologyofmicrobialkeratitis variesaccordingtogeographicregion,economicactivity,and climaticdifferences.Thus,itisbelievedthatpriorknowledge oftheepidemiologicalcharacteristicsofagivenregion, com-binedwithclinicalsuspicion,canguideempiricaltherapy.3_For

https://doi.org/10.1016/j.bjm.2018.05.002

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instance,oculartraumacausedbyvegetablematterhasbeen showntoberesponsibleforkeratitisoccurrence,particularly inlow-incomecountriesandareas thatfeatureagricultural economies.1,4

Duetotheaggressivenessofvariousetiologicagents,early

diagnosis and treatment are essential to prevent

compli-cations,such asendophthalmitis, cornealtransplants, and visionloss.Althoughnotalwaysavailable,theuseof labora-torytestsplaysanimportantroleincasesofmicrobialkeratitis whenassistingtheophthalmologistindeterminingthe opti-maltherapeuticapproach.7–9

Thisstudycomparedpatientswithandwithoutnon-viral

microbialkeratitisinrelationtosociodemographicvariables, clinicalaspects,andinvolvedetiologicagentstobetter under-standthe dynamics ofthis infection, whichfeatures rapid clinicalprogressionandhighmorbidity.

Methods

Thiswasacase–controlstudyconductedataneyeinstitute inthecityofCampoGrande,MatoGrossodoSulstate,Brazil, whichprovidesservicestopatientsfromthecapitalandfrom thecountryside.Patientsthatwereover18yearsoldwith sus-pectedeyeinfection,andwhoattendedtheeyeinstitutefrom 2009to2013,submittedtobiomicroscopyandbiological mate-rialcollectionforthelaboratoryexamination,wereincluded inthisstudy.

Thepatientsweredividedintotwogroups:cases–patients withclinicalmanifestationsandadiagnosisofkeratitis,as veriﬁedbythe presenceofepithelialdefects andepithelial or stromal inﬁltration, and attested inbiomicroscopy; and controls– patientswith eyediseases thatwere not kerati-tis,suspectedconjunctivitis,Chlamydiatrachomatisinfection, endophthalmitis, blepharitis, dacryocystitis, and other dis-easesthatarenotlocatedinthecornea.

The study variables were as follows: sex, age, work

activity, the presence of comorbidities, contact lens wear,

previous surgery, ocular trauma, concurrent eye injuries,

symptoms, clinical signs, clinical specimens sent for

lab-oratory examination, microbiological examination results,

pre-andpost-treatmentfollowingmicroorganism identiﬁca-tion,andclinicalevolution.Microbiologicalanalysisincluded researchandcultureforbacteria,fungi,andAcanthamoeba.

Corneal scraping was obtained with a sterile blade

and plated directly onto different culture media, included Sabouraudagar,5%sheepbloodagar,andthioglycolatebroth.

Blood agar underwent incubation at 35◦C for a period of

24–36hand Sabouraudagar underwentincubationat25◦C, foramonth.

Otherocularspecimenswereobtainedwithcottonswab

applicatorsandseededontobrain-heartinfusionbroth(BHI),

chocolateagarand5%sheepblood agarorasrequestedby

thespecialistphysician.Chocolateandbloodagarsunderwent incubationat35◦Cforaperiodof24–36h,andthenat25◦C foruptomoreweeks.

The corneal smear exhibit little adherence to glass

microscope slides. They should be ﬁxed in ﬂame forlater

staining with Gram’s stain, or they should be previously

ﬁxedinmethanol,forMayGrünwald–Giemsa’sstain3,17_It_is

recommendedthatoneslidebeinitiallystainedwithGram

andthenobservedmicroscopically,duetothesmallamount ofmaterialobtainedduringthecollection.Anobserverwith this typeofsamplecan visualizebacteria, yeasts,

ﬁlamen-tous fungi, Acanthamoeba, and the presenceofsmall oval

sporemicrosporidia.Gram’sstainwastheﬁrstperformedand observedforallspecimens.

With asecond reserved slidefeaturing acorneal

scrap-ing sample,theresearchercanchooseeitheranother stain oramoreappropriatemethodology,asguidedbythe

obser-vationoftheﬁrst,suchasMayGrünwald–Giemsa,modiﬁed

Ziehl–Neelsen’sstain,electronmicroscopy,andothers. Toverifythepossibleassociationsbetweenthestudy vari-ables, the chi-squaredtestor Fisher’sexact testwere used ata5%significancelevel. Toestimate the oddsratios (OR) adjustedwiththerespective95%confidenceintervals,logistic regressionwasused,inwhichvariablesthatwere<20% signif-icantwerepreselectedfirst,andweresubsequentlyexcluded bybackwardselection,inordertodetectpotentially impor-tantconfounders.Theprogramsusedwere:EPIINFOversion 7(CentersforDiseasesControlandPrevention,Atlanta,GA, USA)andBioEstat5.3(MamirauáSociety,Belém,Pará,Brazil). ThisstudywasapprovedbyBrazil’sMinistryofHealth Plat-form,undertheCAAE22284913.1.0000.0021protocol.

Results

Sixty-fourpatientswithkeratitis(cases)and47without kerati-tis(controls)werestudied.ThedatainTable1showthatthere

were no associations betweenkeratitis occurrenceand the

followingvariables:sex,age,thepresenceofcomorbidities, previous eyesurgery (up to3 years prior tothe investiga-tion), injuries, or concomitant clinical aspects (glaucoma, ocularneoplasia,blepharitis,lagophthalmos,entropion, con-junctivainjury,andpost-surgicalinfection).Conversely,there wasanassociationbetweenthedevelopmentofkeratitisand agricultural-andcattleraising-relatedlaboractivity,prior

ocu-lar trauma, and the use ofcontact lenses. However, there

wasnostatisticallysigniﬁcantdifferenceintheproportionof patientsexhibitingimproperlenswearandcareinthegroups withandwithoutkeratitis(Table1).

In64patientswithkeratitis,themostfrequentlyreported symptomswerepain(n=47;73.4%)andphotophobia(n=27;

42.2%). Amongthe 47 patients without keratitis,the main

complaintswereburningandtearing(n=17;36.2%), conjunc-tivalredness(n=15;31.9%),andsensationofsandoraforeign bodyintheeyes(n=13;27.7%).

The main clinical specimens sent for microbiological

examinationwereobtainedbycornealscraping(n=47;73.4%) andviacontactlenses(n=14;21.9%),whileinpatients with-outakeratitisdiagnosis(n=47),conjunctivaldischarge(n=36; 76.6%)andtarsal–conjunctivalscraping(n=10;21.3%)werethe

mostfrequentlyusedmethods.

Regardingtheetiologyofinfectiousprocesses,when com-paring casesandcontrols, itwas observedthatthere were morecasesofbacterialinfection(n=36;76.6%)inthegroup without keratitis (n=47)and a higherpercentageof fungal infection(n=25;39.1%)inpatientswithkeratitis(n=64).The listofidentiﬁedmicrobialagentsisshowninTable3.

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Table1–Associationbetweenkeratitisoccurrenceandthestudyvariables.

Variables Keratitis(n=64) Withoutkeratitis(n=47) p

No_. _% _No_. _%

Sex

Male 36 56.2 22 46.8 0.325a

Female 28 43.8 25 53.2

Agegroup

From18to20yearsold 6 9.4 4 8.5 0.193b

From21to40yearsold 34 53.1 18 38.3

Laboractivity Noinformation 1 1.6 1 2.1 <0.001a Retired/homemaker/student 23 35.9 19 40.4 Farming 21 32.8 1 2.1 Serviceprovision/commerce/industry 19 29.7 26 55.3 Comorbiditytypec Diabetes 10 15.6 5 10.6 0.448c Hypertension 2 3.1 1 2.1 1.000c Anemia 2 3.1 – – 0.507c Cancer 2 3.1 – – 0.507c Heartdisease 1 1.6 1 2.1 1.000c Autoimmunedisease 1 1.6 – – 1.000c Sinusitis 1 1.6 – – 1.000c Hypothyroidism – – 1 2.1 0.423c

Contactlensesuse

Yes 25 39.1 4 8.5 <0.001b

No 39 60.9 43 91.5

Inadequatecontactlensesuse

Yes 11 17.2 8 17.0 0.982c

No 53 82.8 39 83.0

Previousocularsurgery(upto3years)

Yes 4 6.3 4 8.5 0.720c No 60 93.7 43 91.5 Traumatypec Withvegetable/wood/land/animal 19 29.7 – – <0.001b Metalobject 3 4.7 – – 0.261c Eyescratching 1 1.6 – – 1.000c

Injuriesorconcomitantclinicalaspectsc

Conjunctivalandintraepithelialneoplasia 8 12.5 1 2.1 0.076c

Blepharitis 2 3.1 – – 0.507c

Lagophthalmos 1 1.6 – – 1.000c

Glaucoma 1 1.6 – – 1.000c

Irislesioninchildhood – – 1 2.1 0.423c

Entropion – – 1 2.1 0.423c

Post-surgicalinfectiousprocess – – 1 2.1 0.423c

Conjunctivalinjury – – 1 2.1 0.423c

Note:The“noinformation”category,whenpresent,wasremovedfromthestatisticalcalculation.

a _Chi-squared_test.

b _Chi-squared_tendency_test.

c _Each_patient_could_have_one_or_more_types_of_{comorbidities,}_trauma,_injury,_or_concurrent_clinical_aspects.

p,signiﬁcance.

Table2–Logisticregressionforthefactorsassociatedwithkeratitisoccurrence.

Variables p Oddsratio(OR) CI95%(OR)

Laboractivity(farming) <0.001 44.70 5.44–367.49

Contactlensesuse <0.001 15.68 4.39–55.97

Conjunctivalandintraepithelialneoplasia 0.134 6.15 0.57–66.22

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Table3–Microorganismsidentiﬁedingroupswithandwithoutkeratitis.

No_. _% _No_. _% Microorganisma Absenceornogrowth 17 26.6 11 23.4 0.705b Bacteria 27 42.2 36 76.6 <0.001b Fungi 25 39.1 2 4.3 <0.001b Protozoan 4 6.3 – – 0.139c Bacteriaa

Gram-negativebacilli(non-fermenter)

Pseudomonasaeruginosa 8 12.5 9 19.1 0.337b Stenotrophomonasmaltophilia 1 1.6 2 4.3 0.573c Sphingomonaspaucimobilis – – 1 2.1 0.423c Achromobacterxylosoxidans 2 3.1 – – 0.507c Acinetobacterbaumannii 1 1.6 – – 1.000c Elizabethkingiameningoseptica 1 1.6 – – 1.000c Ralstoniapickettii – – 1 2.1 0.423c

Gram-negativebacilli(Enterobacteria)

Enterobactercloacae 1 1.6 – – 1.000c Escherichiacoli 1 1.6 – – 1.000c Serratiasp. 3 4.7 – – 0.261c Citrobactersp. 1 1.6 1 2.1 1.000c Enterobactersp. 1 1.6 1 2.1 1.000c Gram-positivecocci

Staphylococcuscoagulasenegative 1 1.6 1 2.1 1.000c

Micrococcussp. 1 1.6 – – 1.000c Staphylococcusaureus 1 1.6 12 25.5 <0.001b Streptococcuspneumoniae – – 3 6.4 0.073c Other Chlamydiatrachomatis – – 5 10.6 0.012c Fungi Fusariumsp. 9 14.1 – – 0.009c Aspergillussp. 3 4.7 – – 0.261c Candidaalbicans 2 3.1 – – 0.507c Cladophialophorasp. 1 1.6 – – 1.000c Madurellasp. 1 1.6 – – 1.000c Microsporídia 1 1.6 – – 1.000c Protozoan Acanthamoebasp. 4 6.3 – – 0.136c

a _One_or_more_types_of_{microorganisms}_identiﬁed_per_patient.

b _Chi-squared_test.

c _Fisher’s_test.

p,signiﬁcance.

In patients with bacterial keratitis, bacterial infections wereparticularlycausedbyPseudomonasaeruginosa.Therewas nodifferenceinthe percentageofinfection byP. aeruginosa

betweengroups, but there was ahigher infection

percent-agebyStaphylococcusaureus(25.5%)andChlamydiatrachomatis

(10.6%) in patients without keratitis (n=47) (Table 3). In patientswithkeratitis,fungalinfectionsweremainlycaused byFusarium spp. and Aspergillus spp., while inthe control group,nofungalagentswereidentiﬁed(Table3).

AccordingtodatafromTable4,38(59.4%)patientswith ker-atitis(n=64)and43(91.5%)patientswithoutkeratitis(n=47) hadnotusedanymedicinepriortospecimencollectionfor

the microscopic examination. There was greater medicine

useinpatientswithkeratitis,andthemostcommonlyused werethefourth-generationﬂuoroquinolone(n=16;25.0%)and aminoglycosides(n=11;17.2%).

Regardingtheuseofmedicinefollowingthemicroscopic

examination(Table4),inpatientswithkeratitis(n=64),there wasahigheruseoffourth-generationﬂuoroquinolone(n=26; 40.6%),amphotericinB(n=20,31.3%),andnatamycin(n=18; 28.1%);inpatientswithoutkeratitis(n=47),doxycycline(n=5; 10.6%)andthird-generationcephalosporins(n=4;8.5%)were mostfrequentlyused.

Asummaryofthemainmicroorganismsinvolvedinboth

casesand controls,andofthepatientsthat usedmedicine beforeand afterthemicrobiologicalcollection, isshownin

Fig.1.

Inrelationtotheclinicalevolution,inbothcasesand con-trols,allsurveyedpatientsweremedicallydischargedandonly one patient withkeratitis experienced recurrence. Patients withoutkeratitisshowednosequelae,exceptforone,whohad apupildeformity.

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Variables Keratitis Without keratitis

Bacteria

Pseudomonas aeruginosa X X

Staphylococcus aureus X Chlamydia trachomatis X Fungi _Fusarium_sp _X Medication Before collection None X Fourth-generation fluoroquinolone X Aminoglycosides X

After collection

Fourth-generation fluoroquinolone X Amphotericin B X Natamycin X Doxycycline X Third-generation cephalosporin X Ciprofloxacin X X Aminoglycosides X X Ophthalmic lubricant X X

Fig.1–Microorganismsandmedicationtakenpriorandaftertosamplecollectioninpatientswithandwithoutkeratitis. “X”inbothgroupsindicatesthattherewerenostatisticallysigniﬁcantdifferences.“X”inonly1groupindicatesthatthe frequencyinthatgroupwasstatisticallysigniﬁcantlyhigherwhencomparedtotheothergroup.

Amongthosepatientswithkeratitis(n=67),7(10.9%) devel-opedcornealopacity, 10 (15.6%) had cornealperforation, 7

(10.9%) underwent corneal transplantation, and one (1.6%)

underwentscleralgraft.Inthree(4.7%)patients,evisceration wasrequired,andintwoofthem,ocularprosthesiswas nec-essary.Nopatientswithoutkeratitishadcornealperforation orevisceration,andtheydidnotrequirecorrectivemeasures.

Discussion

Although sex, in this series, was not related to keratitis occurrence, epidemiological studies in southeastern Brazil showedthatthehighestnumberofkeratitiscasesoccurredin malepatients.3,10_This_difference_in_the_incidence_of_keratitis

betweensexes,wouldberelatedtosocioeconomicaspects. Previousstudiesshowedthateyedisordersmostlyaffected individualsbetweentheagesof30and60yearsold.1,3,6,7_It_is

believedthatthehighestnumberofkeratitiscasesobserved

inthis studywasamongpatientsagedfrom 21to40years

old,withameanageof31years,whichmayberelatedtothe

numberofcontactlenswearers,likewisesomeauthorshad

reported.6,11

Accordingtothemultivariateanalysisinthepresentstudy, itwasfoundthatthechanceofdevelopingkeratitiswas16 timeshigheramongcontactlenseswearers(Table2). Phys-iopathologically,contactlensescaninducecornealhypoxia, andtheprobabilityofmicro-lesionsandinfectionincreases.12

Theresultsobtainedinthisstudycorroboratetheﬁndings ofotherauthors,whodescribedahighfrequency(49.3%and

64.9%) ofkeratitis amongthose who engage in farm work

andother outdoor activities,respectively, astheyare more

likelytoexperienceoculartrauma.3,4,10_The_chance_of_keratitis

occurrencewas45timeshigherinpeoplewhoselaboractivity waslinkedtofarming(Table2).Theuseofsafetyglassesand promptmedicalattentionincasesofoculartraumaare mea-suresthatcanreducetheincidenceofkeratitisamongthis groupofworkers.1

Evidence has shown that metabolic, systemic, and

immunosuppressant diseases are predisposing factors for

manypathologies,includingoculardiseases,highlightingthe existenceofbacterialkeratitis.2,3 _However,_in_this_study,_no

associationwasfoundbetweendiabetes,othercomorbidities, andkeratitisoccurrence.

Manyreportshavedocumentedthatprioreyesurgerycan

constituteariskfactorforeyeinfection,withratesranging from 1%to35%.5,13 _In_this_study,_no_association_was_found

betweenpreviouseyesurgeryandkeratitisoccurrence, proba-blyduetothesmallnumberofsurgicalproceduresperformed bypatientswithkeratitis(4/64);anequalnumberofsurgeries wasalsoperformedinthecontrolgroup(4/47).

Keratitis presents withdifferent clinical manifestations, althoughtheyarenotpathognomonicofthisdisease.Inthis study,symptomssuchaspainandphotophobiawerefoundto besigniﬁcantlyassociatedwithkeratitis,becausethecornea itisadenselyinnervatedtissue.14

Inpatientswithoutkeratitis,therewasahigherpercentage ofburning,tearing,conjunctivalredness,and sensationsof sandoraforeignbody,likeinothersstudies.15

Theetiologicidentiﬁcationofmicrobialkeratitis is chal-lengingdue tothefact thatit isdifﬁculttoobtain corneal

specimens; there is also a lack of appropriate

microbio-logical techniques.16 _In _routine _eye _care, _collections _are

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Table4–Medicinesusedbeforeandaftersamplecollectionformicroscopicexaminationingroupswithandwithout keratitis.

No_. _% _No_. _%

Medicinesbeforecollectiona

None 38 59.4 43 91.5 <0.001b Fourth-generationﬂuoroquinolone 16 25.0 1 2.1 0.002b Aminoglycosides 11 17.2 – – 0.002c Acyclovir 4 6.3 – – 0.136c AmphotericinB 3 4.7 – – 0.261c Third-generationcephalosporin 2 3.1 2 4.3 1.000c Ciproﬂoxacin 2 3.1 – – 0.507c Corticoid 2 3.1 – – 0.507c SulfamethoxazoletrimethoprimF 1 1.6 – – 1.000c Natamycin 1 1.6 – – 1.000c Chloramphenicol 1 1.6 – – 1.000c Decadron 1 1.6 – – 1.000c PropamidineIsethionate 1 1.6 – – 1.000c Therapeuticlenses 1 1.6 – – 1.000c Ophthalmiclubricant 1 1.6 1 2.1 1.000c Doxycycline – – 3 6.4 0.073c Bevacizumab – – 1 2.1 0.423c Vancomycin – – 1 2.1 0.423c

Medicinesaftercollectiona

Fourth-generationﬂuoroquinolone 26 40.6 9 19.2 0.042b AmphotericinB 20 31.3 – – <0.001b Aminoglycosides 18 28.1 15 31.9 0.666b Natamycin 18 28.1 – – <0.001b Ophthalmiclubricant 9 14.1 7 14.9 0.902b Ciproﬂoxacin 8 12.5 10 21.3 0.215b Ketoconazole 5 7.8 – – 0.071c Acyclovir 4 6.3 – – 0.136c Biguanide 4 6.3 – – 0.136c Atropine 2 3.1 – – 0.507c Fluconazole 2 3.1 – – 0.507c Mebendazole 1 1.6 – – 1.000c Azithromycin 1 1.6 5 10.6 0.081c Chloramphenicol 1 1.6 1 2.1 1.000c Itraconazole 1 1.6 1 2.1 1.000c Propamidineisethionate 1 1.6 – – 1.000c Corticoid 1 1.6 – – 1.000c Doxycycline – – 5 10.6 0.012c Third-generationcephalosporin – – 4 8.5 0.030c Dexamethasone – – 2 4.3 0.177c Vancomycin – – 2 4.3 0.177c SulfamethoxazoletrimethoprimF – – 1 2.1 0.423c

Ciproﬂoxacinhydrochloride0.3%with

dexamethasone0.1%

– – 1 2.1 0.423c

a _Each_patient_could_have_used_one_or_more_types_of_medicine.

b _Chi-squared_test.

c _Fisher’s_test.

p,signiﬁcance.

bent; this method requires a highly skilled

ophthalmolo-gist. Ideal corneal scrapings should be collected from the

base and margin of the ulcers, using the Kimura

spat-ula or a sterile blade, under direct vision through a slit lamp.3

Despite these difﬁculties, our culture-positive rate was

73.4% for keratitis cases and 76.6% for patients without

keratitis.Thisﬁnding,aswellasourabilitytoidentifydata per-tainingtothevariouscausativeagents,asobtainedthrough microbiologicaltests,andrepresentthepositiveaspectsofthis

research.Differentauthorsobtainedpositivityratesthatfell between29%and61%.3,17

DifferentBrazilianstudieshavereportedapredominance ofGram-positivecocciinbacterialkeratitis,witha predomi-nanceofStaphylococcusspp.3,17_In_this_study,_a_{Gram-negative}

microorganism,Pseudomonasaeruginosa,wasmostfrequently identiﬁed.Otherstudiesdescribingtheprevalenceof

Gram-negative bacilli have been associating its incidence with

higher temperatureregionsand theuseor wearofcontact

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Withrespecttothefungal etiologyofkeratitis,Fusarium

sp. was the most frequently isolated fungus, according to

otherauthors.3,10_Among_the₆₄_cases_of_keratitis_investigated

herein,twopatientswereobservedwithdematiaceousfungi isolates:Cladophialophorasp.andMadurellasp.Thesearefound intheenvironmentandarenotusuallyisolatedfromkeratitis samples.2,19

Moreover,ofthecasesexaminedinthisreport,the

identi-ﬁcationofanimmunocompetentpatientwithmicrosporidial

keratitiswashighlighted.Reclassiﬁedasafungusin2001,this

pathogenhasbeenconsideredemergentinothercountries,

notonlyinpatientswithAIDS,butalsoin

immunocompe-tentindividuals.Microsporidiadoesnotgrowinculturemedia, norisitwellevidencedbystainingmethodsusedinroutine laboratorysettings.20–23

Insuspectedpicturesofmildormoderatemicrobial

ker-atitis, the use of ﬂuoroquinolone monotherapy, as in this

study, is being increasingly used due to its proven

effec-tiveness when compared with the use of cephalosporins

and aminoglycosides.24 _The _importance _of _microscopic

examinationcanbeobservedintheanalysisofpre-and post-medicationsamplecollection.Itwasfoundthatpropamidine

isethionateand biguanidewereused followingsample

col-lectionsformicroscopytestsofAcanthamoebatreatment.The samesituationwasobservedforMicrosporidia,inwhich

treat-mentwithmebendazolewasalsoestablished.

Due to the morbidity ofmicrobial keratitis,particularly givenitsimpairmentofocularstructures,moredrastic

mea-sures are often required to treat this condition (corneal

transplants,eviscerationoftheeye,grafts,andocular pros-thesisplacement),asdemonstratedinthisstudy.Itisbelieved thatlatediagnosisisoneofthereasonswhycomplications associatedwith infectious processes develop,and this can occurinregionscharacterizedbylargegeographical dimen-sionsthatdonothaveaccesstotreatmentbyspecializedeye centers.

Thelimitationsofthisstudyaremainlyassociatedwiththe factthatthisstudy wasaretrospectiveinvestigation.There wereanumberofissuesassociatedwithalackofsystematic andstandardizedrecords,suchasthelackofmoredetailed dataregardingtheinadequateuseofcontactlenses.In addi-tion,pre-treatmentuse ofcontactlensesbysomepatients mayhaveaffectedtheresultsofthemicrobiologicaltests.

Theoculartraumaexperiencedinconnectionwithlabor

activitycanbepreventedthroughtheuseofpersonal protec-tiveequipment.However,therearemanyquestionsregarding the use ofcontactlenses and the occurrenceofinfectious eyediseases.Thereisaconsensusamongmanyauthorsthat bothhardandgelatinlenses,madefrommaterialswithhigh oxygenpermeability,adverselyinﬂuencethecentral epithe-lial proliferation rates of the cornea, which indicates that

themechanicalpresenceofalens isenoughtochangethe

level of epithelial homeostasis when compared with

indi-vidualswhodonotwearcontactlenses.25,26 _Further_studies

are needed to explore the use of contact lenses,

espe-cially given their increasing popularity among youth and

adolescents.

Conﬂicts

of

interest

Theauthorsdeclarenoconﬂictsofinterest.

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