EXTERNAL EYE INFECTIOUS DISEAESE FARABI EYE HOSPITAL

Transcription

1 EXTERNAL EYE INFECTIOUS DISEAESE R.GHAFFARI MD FARABI EYE HOSPITAL

2 Normal flora of the outer eye

3 Conjunctival Infectious disease

4 CONJUNCTIVAL INFECTIONS 1. Bacterial Simple bacterial conjunctivitis Gonococcal keratoconjunctivitis 2. Viral Adenoviral keratoconjunctivitis ti iti Molluscum contagiosum conjunctivitis Herpes simplex conjunctivitis 3. Chlamydial Adult chlamydial keratoconjunctivitis Neonatal chlamydial conjunctivitis Trachoma

5 Simple bacterial conjunctivitis Signs Crusted eyelids and conjunctival Subacute onset of mucopurulent injection discharge Treatment broad spectrum topical antibiotics

6 Gonococcal keratoconjunctivitis Signs Complications Acute, profuse,,purulent discharge, g, hyperaemia and chemosis Corneal ulceration, perforation and endophthalmitis if severe Treatment Topical gentamicin and bacitracin Intravenous cefoxitin or cefotaxime

7 Adenoviral Keratoconjunctivitis 1. Pharyngoconjunctival fever Adenovirus types 3 and 7 Typically affects children Upperrespiratory respiratory tract infection Keratitis in 30% usually mild 2. Epidemic keratoconjunctivitis Adenovirus types 8 and 19 Very contageous No systemic symptoms Keratitis in 80% of cases may be severe

8 Signs of conjunctivitis Usuallybilateral bilateral, acute watery discharge and follicles Subconjunctival haemorrhages and pseudomembranes if severe Treatment symptomatic

9 Signs of keratitis Focal, epithelial keratitis Transient Focal, subepithelial keratitis May persist for months Treatment topical steroids if visual acuity diminished by subepithelial keratitis

10 Molluscum contagiosum conjunctivitis Signs Waxy, umbilicated eyelid nodule May be multiple Ispilateral, chronic, mucoid discharge Follicular conjuntivitis Treatment destruction of eyelid lesion

11 Herpes simplex conjunctivitis Signs Unilateral leyelid vesicles il Acute follicular conjunctivitis Treatment topical antivirals to prevent keratitis

12 Adult chlamydial keratoconjunctivitis Infection with Chlamydia trachomatis serotypes D to K Concomitant genital infection is common Subacute, mucopurulentfollicular conjunctivitis Variable peripheral keratitis Treatment topical tetracycline and oral tetracycline topical tetracycline and oral tetracycline or erythromycin

13 Trachoma Infection with serotypes A, B, Ba and C of Chlamydia trachomatis Fly is major vector in infection reinfection cycle Progression Acute follicular conjunctivis i Conjunctival scarring (Arlt line) Herbert pits Pannus formation Trichiasis Cicatricial entropion Treatment systemic azithromycin

14 Diagnostic work up Conjunctival scrapings and cultures should be obtained : In severe bacterial conjunctivitis Those cases when antibacterial therapy is ineffective i Infants

15 Laboratory diagnosis The use of conjunctival scrapings in the diagnosis of bacterial conjunctivitis can proceed as follows: Conjunctivalscrapingscan can beperformed with topical anesthetic and gentle use of a platinum spatula or similar blunt metallic object. Gram stain is useful for identifying bacterial characteristics. Giemsa stain is helpful in screening for intracellular inclusion bodies of Chlamydia.

16 Thecellular response in conjunctivitis differs according to the cause, as follows: Bacterial infections: Neutrophils predominate Viral infections: Lymphocytes predominate Allergic reactions: Eosinophils predominate

17 Additional tests PCR may be usefull in detection of causative organism

18 Infective Keratitis 30,000 cases annually in the US(Bacterial, Fungal and Acanthanoeba) (Pepose JS et al AJO 1992) Bacterial Keratitis rarely occurs in normal eyes because of human cornea s natural resistance to infection

19 Risk Factors Exogenous factors Contact lens use Trauma Previous ocular/eyelid surgery Loose sutures Previous Corneal Surgery (incl. Lasik & PRK) Medication related and medicamentosa (contaminated ocular medications, topical NSAIDS, anesthetics, antimicrobials, preservatives, glaucoma medications) Immunosuppresion Factitious disease (incl. anesthetic abuse)

20 Risk factors Corneal Epithelial Abnormalities Neurotrophic Keratopathy Disorders predisposing to recurrent corneal erosion Viral Keratitis Corneal epithelial oedema, especially bullous keratopathy

21 CORNEAL INFECTIONS 1. Bacterial keratitis 2. Fungal keratitis 3. Acanthamoeba keratitis 4. Infectious crystalline keratitis 5. Herpes simplex keratitis Epithelial Disciform 6. Herpes zoster keratitis

22 Common etiological agents of bacterial keratitis in the U.S. (AAO Preferred Practice Pattern Aug 2005-Bacterial Keratitis) Class/Organism Common Isolates* Cases (%) Gram-Positive Isolates Gram-positive Cocci Staphylococcus aureus 4 30 Coagulase negative Staphylococci 5 40 Streptococcus pneumoniae 1 25 Streptococcus viridans group 1 15 Gram-positive Bacilli Corynebacterium species es 1-5 Propionibacterium species 1-12 Mycobacterium species 1-2 Gram-Negative Isolates Gram-negative Bacilli Pseudomonas aeruginosa 5-45 Gram-negative Coccobacillary organisms Serratia marcescens 1-12 Proteus mirabilis 1-5 Enteric gram-negative bacilli, other 1-10 Haemophilus influenzae, other 1-6 Haemophilus species 1-5 Moraxella species and related species Gram-negative Cocci Neisseria species 1

23 Natural History of Bacterial Keratitis Corneal scarring (significant visual loss if invl. central visual axis) Corneal perforation Endophthalmitis Rapid progression(24 hrs) pseudomonas, gonococcal Indolent course atypical mycobacteria viridans Indolent course atypical mycobacteria, viridans type streptococcus

24 Bacterial keratitis Predisposing factors Contact tlens wear Chronic ocular surface disease Corneal hypoaesthesia Expanding oval, yellow white, dense stromal infiltrate Stromal suppuration and hypopyon Treatment topical ciprofloxacin 0.3% or ofloxacin 0.3%

25 Fungal keratitis Frequently preceded by ocular trauma with organic matter Greyish white ulcer which may be Slow progression and occasionally surrounded by feathery infiltrates hypopyon Treatment Topical antifungal agents Systemic therapy if severe Penetrating keratoplasty if unresponsive

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27 Acanthamoeba keratitis Contact lens wearers at particular risk Symptoms worse than signs Small, patchy anterior stromal infiltrates Perineural infiltrates (radial keratoneuritis) Ulceration, ring abscess Stromal opacification & small, satellite lesions Treatment chlorhexidine or polyhexamethylenebiguanide

28 Infectious crystalline keratitis Very rare, indolent infection (Strep. p viridans) ) Usually associated with long term topical steroid use Particularly following penetrating keratoplasty White, branching, anterior stromal crystalline deposits Treatment topical antibiotics

29 Herpes simplex epithelial keratitis Dendritic ulcer with terminal bulbs Stains with fluorescein May enlarge to become geographic Treatment Aciclovir 3% ointment x 5 daily Trifluorothymidine 1% drops 2 hourly Debridement if non compliant

30 Herpes simplex disciform keratitis Signs Associations Central epithelial and stromal oedema Folds in Descemet membrane Small keratic precipitates Occasionally surrounded by Wessely ring Treatment topical steroids with antiviral cover

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32 Geographic HSK

33 Acute epithelial keratitis Herpes zoster keratitis Nummular keratitis Develops in about 50% within 2 days of rash Small, fine, dendritic or stellate epithelial lesions Tapered ends without bulbs Resolves within a few days Develops in about 30% within 10 days of rash Multiple, fine, granular deposits just beneath Bowman membrane Halo of stromal haze May become chronic Treatment topical steroids, if appropriate

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35 Initial Assessment History Ocular symptoms Review of prior ocular surgery Review of other medical problems Current ocular medications Drug allergies

36 Initial Assessment Examination General appearance of the patient including skin conditions Facial examination Eyelids and eyelid closure Conjunctiva Nasolacrimal lapparatus Corneal sensation

37 Initial Assessment Slit Lamp Biomicroscopy Eyelid margins Conjunctiva Sclera Cornea Anterior Chamber Anterior Vitreous

38 ANTIBIOTIC THERAPY OF BACTERIAL KERATITIS (AAO BCSC ) Organism Antibiotic Topical Concentration Subconjunctival Dose No organism Cefazolin 50 mg/ml 100 mg in 0.5 ml identified or with 9 14 mg/ml 20 mg in 0.5 ml multiple types of organisms Tobramycin/Gentamicin 3 or 5 mg/ml or Fluoroquinolones Gram-positive cocci Cefazolin 50 mg/ml 100 mg in 0.5 ml Vancomycin* mg/ml 25 mg in 0.5 ml Bacitracin* Moxifloxacin or Gatifloxacin 10,000 IU 3 or 5 mg/ml Gram-negative rods Tobramycin/Gentamicin 9 14 mg/ml 20 mg in 0.5 ml Gram-negative cocci Non-tuberculous mycobacteria Ceftazidime 50 mg/ml 100 mg in 0.5 ml Fluoroquinolones 3 or 5 mg/ml Ceftriaxone 50 mg/ml 100 mg in 0.5 ml Ceftazidime 50 mg/ml 100 mg in 0.5 ml Fluoroquinolones 3 or 5 mg/ml Amikacin mg/ml 20 mg in 0.5 ml Clarithromycin Fluoroquinolones 3 or 5 mg/ml Nocardia Amikacin mg/ml 20 mg in 0.5 ml Trimethoprim/sulfamethoxazole: trimethoprim sulfamethoxazole 16 mg/ml 80 mg/ml

39 DIAGNOSTIC APROACH TO BACTERAIL KERATITIS ROUTIN SMEAR AND CULTURE CASE BASED APROACH EMPRICAL TREATMENT

40 Diagnostic Tests Majority of community acquired infections are successfully treated empirically without smears (Macleod SD et el, Ophthalmology 1996)

41 Diagnostic Tests Smears & cultures are indicated in infections: Prior to initiating treatment in sight threatening and severe keratitis Deep and large stromal infiltrates involving the visual axis Re cultures are Necessary Chronic Unresponsive to broad spectrum antibiotic Features suggestive of fungal, amoebic or mycobacterial keratitis

42 Diagnostic Tests Role of smears & cultures Useful in guiding modification of therapy in patients with poor clinical response to initial broad spectrum therapy Allows elimination of unnecessary drugs hence reducing toxicity In cultures taken from patients not responding to empirical treatment, treatment may be stopped for 12 to 24 hours prior to re culturing.

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44 CULTURE MEDIA FOR BACTERIAL KERATITIS (AAO Preferred Practice Pattern Bacterial Keratitis) Standard Media Common Isolates Blood agar Aerobic and facultatively anaerobic bacteria, including P. aeruginosa, S. aureus, S. epidermidis, idi S. pneumoniae e Chocolate agar Aerobic and facultatively anaerobic bacteria, including H. influenzae, N. gonorrhea, and Bartonella species Thioglycollate broth Aerobic and facultatively anaerobic bacteria Supplemental Media Anaerobic blood agar (CDC, Schaedler, Brucella) P. acnes, Peptostreptococcus Löwenstein-Jensen e medium Mycobacteria species, Nocardia species Middlebrook agar Thayer-Martin agar Mycobacteria species Pathogenic Neisseria species NOTE: Fungi and acanthamoeba can be recovered on blood agar. However, more specific media are available (fungi: Sabouraud dextrose agar, brain heart infusion agar; acanthamoeba: buffered charcoal yeast extract, blood agar with E. coli overlay).

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49 additional Tests Corneal Biopsy Lack of response More that 1 negative culture result Deep stromal infiltrate with normal overlying tissue With a corneal graft on standby PCR confoscan

50 THANKS FOR YOUR ATTENTION