眼内炎PPT医学课件.ppt

1、眼 内 炎分 类(1)感染性眼内炎感染性眼内炎术后-急性术后眼内炎-迟发性眼内炎-青光眼滤过泡相关性眼内炎内源性眼内炎外伤后(2)非感染性眼内炎非感染性眼内炎无菌性葡萄膜炎晶状体过敏性眼内炎交感性眼内炎急 性 术 后 眼 内 炎感染性眼内炎发生于内眼手后(60 分钟)-玻璃体丢失-inadequate draping of lids and lashes away from the surgical site危险因素术后-伤口渗漏或裂开-不适当的埋线-拆线-玻璃体嵌顿-存在一个滤过泡-缝线脓肿 评估Differentiate PL from Hand movement VA-major fac

2、tor in decision for vitrectomy(based on endophthalmitis vitrectomy study)-no closer than 60cm,with light illumination from behind the patientU/S evaluation if fundal view obscured-dispersed vitreous opacities-chorioretinal thickening-RD or choroidal detachment-dislocated lens material-retained forei

3、gn bodiesDifferential DiagnosisOccult retention of lens materialToxic anterior segment syndrome-sterile inflammation due to non-infectious,toxic substances that enter the AC during or after intraocular surgery-eg.preservatives,detergents,cleaning compounds,intraocular solutions,with inappropriate ch

4、emical comosition,pH or osmolality-rapid onset(12-24 hours of surgery)-lack of isolated organisms by gram stain or culture-predominance of anterior inflammationAnterior segment infection by contiguous structures eg blebitis,keratitishypopyon uveitis(eg.Behcets disease)Microbiloogical characteristics

5、most commonly by bacteriaFungal infection may occur in conjunction with the use of contaminated ocular irrigating fluidscausative organisms usually represent bacteria from patients own periocular flora,introduced into the eye during surgery.Gram positive bacteria(94.2%)1Gram negative bacteria(5.9%)P

6、revention:Prophylactic antibioticsPre-op-prophylactic preoperative topical antibiotics shown to reduce number of potential pathogens after a 1-2day pre-op course-not proven to reduce the incidence of endophthalmitis-opponents argue this may lead to antibiotic resistance or induce allergic reactions-

7、should be bactericidal to gram+ve and gram-ve bacteria-treatment should be 1-2 days pre-op to reduce the replacement of indigenous flora with gram negative and opportunistic pathogens,and to prevent emergence of antiobiotic resistant bacterial strainsIntra-op-administration of topical 5%povidone-iod

8、ine into the conjucntival sac significantly reduced the incidence of endophthalmitis5-effective against bacteria,fungi,viruses,protozoa and sporesPost-op-subconjunctival antibiotics:not proven-poor vitreal penetrationInvestigations:CulturesVitreous samples yielded+ve cultures more often thn aqueos s

9、amplesmoorelikely to be only source of+ve culture in a small minority of ptsno difference in yield between cultures obtained by needle tap vsss vitreous biopsy vs TPPVFailure to obtain+ve cultures-low microbial counts-fastidious organisms(require specialised culture medium)-spontaneous sterilization

10、 during oculr inflammatory response eg staph epidermidis-non-infectious inflammationValue of microbiological investigations:-establishes infectious aetiology-tailoring of treatment if intravitreal injection is required-medico-legal considerations-epidemiological studiesRole of PCR:-particularly usef

11、ul in detection of unusual/fastidious organisms-enable detection of organisms in culture negative samples obtained after antibiotic treatment has commnced-Disadvacntages:high sensitivity may lead to false+ve results,does not detect antibiotic sensitivityImmediate Pars plana vitrectomy vs vitreous ta

12、p or biopsy1-pts who presented with PL had a significant 3x improved chance of obtaining 6/12 vision after immediate vitrecotmy(33%)compared to vitreous tap or biopsy(11%)-2x improved chance of obtaining 6/30 or beter vision(56%)compared to vitreous tap or biopsy(30%)-no difference in outcome betwee

13、n pts with HM or better VAManagementIntravitreal antibiotics are the mainstay of treatmentQuickest way of delivering adequate concentration directly to the infected tissuesEmpirical therapy:-vancomycin 1mg/0.1ml and ceftazidime 2.25mg/0.1ml)role of 4th generation fluoroquinolones(eg gatifloxacin,mox

14、ifloxacin)still unclear-broad spectrum,highly active against gram-ve-should be administered incombination with a drug with better gram+ve coverage-optimal dosage in humans not knownIntravitreal antifungalsLinezolidaminoglycosides are a/w retinal toxicity and macula infarction-esp with gentamicin-les

15、s comon with amikacin and tobramycinAmphotericin B is also a/w retinal toxicitySystemic antibiotics-too slow to enter the eye in adequate concentrations,should not be used as the only treatment-has the potential to prolong intravitreal therapy and reduce the need for repeated intravitreal injections

16、-EVS:IV amikacin+IV ceftazidime+PO ciprofloxacin(if allergic to penicillin)in addition to intravitreal abx-no difference in visual outcome-may be related to fact that amikacin does not penetrate well into the vitreous cavity and cipro does not adequately treat gram-veEngelbert et al:Intravenous imip

17、enem with or without intravitreal amikacin+vancomycin-imipenem had good vitreous penetration and broad spectrum coverage including gram+vecombination therapy did not provide additional benefit to intravitreals alone-systemic imipenem alone was inferior to intravitreals aloneOral moxifloxccin/gatyifl

18、oxacin-broad spectrum coverage,good tolerabilitySubconjunctival/topical antibiotics-achives therapeutic levels in the AC but not in the vitreous-retrospective studies have not demonstrated additional benefit when given in conjunction with intravitreals-may be beneficial in cases a/w anterior patholo

19、gy such as suture abscesses and blebitis CorticosteroidsMinimizes ocular damage from host inflammatory responsetopical and subconjunctival steroid injections have been used for acute post op endophthalmitisIntravitreal steroids-controversial-intravitreal dexamethasone:limited evidenceIntervention af

20、ter initial therapyEVS protocol recommended reinjection if the infection was worsning 36-60hours after initial injectionpersistence of infection could be due to resistant strains or sensitive strains not completely eradicated by the 1st injectionincreased virulence of organism is associated with inc

21、reased rate of reinjectionthose requiring additional injections had worse visual outcomesPrognosismost common cause of visual loss:macula abnormalities-epiretinal membranes-macula edema-macula ischemia-pigmentary degenerationOther adverse outcomes:-RD-pthisiselevated IOPenucleation and eviscerationR

22、isk factors associated with poor visual outcome-PL vision at presentation(strongest predictor)-older age-diabetes-corneal infiltrate or ring ulcer-compromised posterior capsule-low or high IOP-RAPD-rubeosis-absent red reflexType of organism affects visual outcome-highly virulent organisms eg.S.aureu

23、s,strep,gram-ve organisms provole significant inflammation and result in worse visual outcome-Coagulase negative staph:84%achieved 20/100 vision or better in the EVS-no growth or equivocal growth a/w favourabe outcome-enterococcus infection had the worst visual outcomeDelayed onset Post-op Endophtha

24、lmitisendophthalmitis occuring 6 weeks post oporganisms include less virulent bacteria and fungal pathogens-P.acnes-Staph epidermidis-Corynebacterium-Candida parasilosisHost characteristics and inoculum size are also important factors that determine the onset of endophthalmitisClinical featurespain

25、may or may not be presentInflammation may be initially steroid responsive but recur after steroid taperInflammation may worsen with steroids in fungal infectionsfrank hypoppyon often absent but microhypopyon may be visible with gonioscopyuveitis may be granulomatous with large KPs on the cornea or i

26、ntraocular lensP.acnes often a/w white intracapsular plaque,with retained lens particles and sequestration of bacteriavitritis is usually mildmany of hte organisms are slow growing(eg P acnes:10 days)thus cultures should be kept for several weeksIntravitreal vancomycin is the treatment of choiceAmph

27、otericin B for fungal infectionPPV with removal of vitreous infiltrates and partial capsulectomy/total capsulectomy with removal of intraocular lens may be needed to remove sequestered bacteriarepeated antibiotic or surgical therapy may be requiredbetter visual outcome compared to acute post op endo

28、phthalmitisFiltering bleb associated endophthalmitisResults from pathhogenic organisms gaining entry to intraocular tissues via conjunctival fitering bleb can occur early,but more often occurs months to years after filtering surgeryRisk factors-use of antifibrotic agents-inferior bleb location-manip

29、ulation with laser suture lysis,needling,autologous blood injection-thin,cytic,avascular bleb-predispose to bleb leaksAcute infections likely results from intraop innoculation:Coagulase negative Staph predominateStreptococcal species predominate in late infections fungal infections are rareCharacter

30、ized by sudden progressive intraocular inflammation in eyes that have been quiet for months or yearspain,redness and decreased vision are the most common symptomsBleb purulence is noted in most patientsNeedle aspiration of the bleb is not recommended:low yield and compromises retention of a function

31、al filtration siteTreatment-conjunctival swab-Intravitreal vancomycin+ceftazidime-topical fortified antibiotics or 4th generation quinolones may provide benefit as an adjunct to intravitreal injections-Busbee et al(in a retrospective study of 68 patients)showed benefit of early vitrectomy with VA at

32、 3 and 12 month follow up and decreased chance o progressing to NPLPrognosis is poor.Only 10-13%achieved 6/12 vision or better at final follow up.(cf acute post op endophthalmitis where 53%achieved 6/12 or better vision)Traumatic Endophtalmitiscomprises 25%of endophthalmitis casesrisk of endophthalm

33、itis after an open globe injury is approximately 7%Intraocular FB increases the risk of endophthalmitisOther risk factors-dirty wound-lens capsule rupture-age 50-delayed presentation of 24hrs(increases with each hour of delay)Onset varies from few days to several weeks,depending on virulenceSymptoms

34、:decreasing vision,increasing pain or greater than expected degree of painSigns:greater than expected AC cells,hypopyon,vitritis,chemosis and lid edema,corneal ring ulcerPathogens-bacillus and staphylococcus are common in penetrating trauma with IOFB-Baciluus are particularly aggressive and are espe

35、cially common in IOFB with organic or soil composition-other organisms:S Epidermidis,Strep,Gram-ve,fungi and mixed floramust exclude the possiblity of occult retained IOFB with imaging studies if there is an inadequate view of intraocular structuresImaging may also be required to determine position

36、of a FB in relation to ther intraoculular structuresTreatment-early primary repair and removal of IOFB-take cultures at time of initial repair(although positive cultures may not predict development of endophthalmitis nor isolate the infective organism)Treatment-intravitreal vancomycin with ceftazidi

37、me-vitrectomy should be considered in severe cases-role of systemic antibiotics is unclearPrognosis is poor-higher occurence of mixed infections and virulent bacteria like bacillus-concurrent damage from initial injury-delay in diagnosis due to confusion in the setting of post traumatic inflammation

38、 Prophylactic antibiotics-intravitreal antibiotics shown to reduce inflammation in animal models of post traumatic endophthalmitis,but evidence not fully established in humans-Essex et al recommended intravitreal antibiotics for cases with 2 out of 3 risk factors:delay in closure 24 hours,dirty woun

39、d,lens breach-Systemic antibiotics are commonly administered although no prospective evidence for benefit has been established-Oral Fluoroquinolones alone may be adequateEndogenous Endophtalmitiscomprises 25%of endophthalmitis casesRelatively rare,accounting for 2-8%of endopthalmitis casesPatients u

40、sually have underlying predisposing factors-diabetes(most common predisposing factor)-HIVIVDArenal failure on dialysiscardiac diseasemalignancyimmunosuppresive therapyin dwelling cathetersExtraocular foci,in order of frequency6:-liver abscess-pneumonia-endocarditis-soft tissue infection-UTI-meningit

41、is-septic arthritis-orbital cellulitisPatients with known systemic infection on appropriate therapeutic antibiotics may still develop endophthalmitis,due to subtherapeutic levels within the eye.Systemic disease may be subtle.Ask for fever,chills and rigors and perform a careful review of systemsInit

42、ial diagnostic error rates are,with non infectious uveitis being the most common diagnosisRelatively few bacteremic patients develop endophthalmitis6:-community acquired infection:0.44%-hospital ecquired infection:0.24%-some develop minor oculr lesions eg cotton wool spots and microhemorrhages-roth

43、spots are septic emboli,occuring in 1%of bacteremic patientsnot all patients with roth spots progress to EBEMicrobiologyBacterial or fungal,rarely parasites(eg toxocara canis or tocoplasmosis)Varies with geographical locationEast Asia:most cases caused by gram-ve,with Klebsiella comprising 80-90%of

44、isolated organismsmay be related to the association of Klebsiella with cholangiohepatic and liver abscess which is more common in East AsiansOther gram negative bacteria:E.coli,pseudomonas aeruginosa,N meningitidis,Serratia marscecensMicrobiologyMost common gram+ve bacteria was staph aureus,followed

45、 by streptococci and listeriafunal endophthalmitis is more common in the West(eg candida albicans and aspergillus)Vitreal and systemic cultures(blood,urine and CSF)must be obtainedSystemic cultures are+ve in 75-80%of cases while ocular cultures are positive in 36-73%of cases6TreatmentSystemic antibi

46、otics are central to the treatment of endogenous endophtalmitis(cf exogenous endophthalmitis)choice of antibiotic is directed at the infection source,guided by cultures and sensitivitiescompromise of the blood retina barrier in the infalmmed eye often allows adequate intraocular penetration of syste

47、mic antibioticssystemic therapy should be continued for several weeks to ensure eradication of the infectionintensive topical steroid therapy and cyclopegia should be administered to prevent inflammatory ocular sequelae.TreatmentFungal infections:-amphoterecin is effective but has significant side e

48、ffects of nephrotoxicity,hypotension and suboptimal ocular penetration-fluconazole has better ocular penetration but has a narrower spectrum-Voriconazole has a good ocular penetration with oral dosing,broad spectrum(including amphotericin resistant organisms),and si well toleratedIntravitreal antibi

49、otics should be administered if there is severe or progressive vitritis-vancomycin 1mg/0.1ml+ceftazidime 2.25mg/0.1ml-amphotericin 5-10ug/0.1ml in fungal endophthalmitis-intravitreal antibiotics did no significantly improve visual prognosis,but eyes that received intravitreal antibiotics were less l

50、ikely to require enucleation or evisceration6Intravitreal steroids-no randomized clinical trials to establish benefit-most animal experiments suggest that intravitreal dexamethasone helps preserve retinal structure and function.(however this was in the context of direct innoculation and therefore si