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Bacterial Keraritis,viral keraritis,fungal
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- 2. Bacterial keratitis Keratitis- Inflammation of the cornea. Microbial keratitis or infectious corneal ulcer is due to the proliferation of microorganisms (including bacteria, fungi, viruses, and parasites) and associated inflammation and tissue destruction within the corneal tissue . Bacterial keratitis - most common cause of suppurative corneal ulceration (disruption of the epithelial layer with involvement of the corneal stroma).
- 3. BACTERIAL KERATITIS • Needsurgent medical attention • Prompt diagnosis • Initiation of appropriate antibiotic • Limit amount of tissue destruction • Improve patient’s visual prognosis
- 4. Risk Factors forbacterial keratits EXTRINSIC FACTORS • Contact lens wear • Trauma • Previous ocular and eyelid surgery • Loose corneal sutures • Medication-related factors • Immunosuppression
- 5. Risk Factors forbacterial keratits Corneal surface disease •Tear-film deficiencies •Abnormalities of the eyelid anatomy and function •Misdirection of eyelashes •Adjacent infection/inflammation- Blepharitis
- 6. Risk Factors forbacterial keratits • Corneal epithelial abnormalities • Neurotrophic keratopathy • Recurrent corneal erosion • Corneal abrasion or epithelial defect • Viral keratitis • Corneal epithelial edema
- 7. Risk Factors forbacterial keratits Systemic conditions • Diabetes • Systemic infections • Collagen vascular diseases • Immuno suppressive drug • Chronic alcholism • Extensive body burns • Drug addiction • AIDS
- 8. Common bacterial pathogensthat cause keratitis Bacterium Typical characteristics of infection Staphylococcus aureus(most common) Staphylococcus epidermidis Infection progresses slowly with little pain Streptococcus pneumoniae Typical serpiginous corneal ulcer: cornea is rapidly Perforated with early intraocular involvement;very painful. Pseudomonas aeruginosa ( most common organism in soft contact lens wearers) Bluish green mucoid exudate,occasionally with a ring shaped corneal abscess.Progressionis rapid with a tendency to ward melting of the cornea over a wide area;painful.
- 9. Clinical features ofGram positive and Gram negative Feature Gram positive Gram negative Appearance Mild to dense infiltrate Dense infiltrate necrosis Borders Distinct infiltrate borders Indistinct borders Surrounding cornea Hypopyon Generally clear Less common Often hazy More common
- 10. 1. White stromalinfiltrate associated with an overlying epithelial defect and secondary anterior uveitis . SIGNS
- 11. 2. Enlargement ofstromal infiltration associated with stromal oedema
- 12. 3.Severe infiltration andhypopyon formation
- 13. 4.Progressive ulceration andenlargement of hypopyon
- 14. 5.Corneal perforation andendophthalmitis in neglected cases
- 15. Differential Diagnosis Nonbacterial cornealpathogens • Fungi • Parasites • Viruses Noninfectious corneal infiltrations • May be associated with contact lens wear. • Systemic dis. eg, collagen vascular and rheumatoid dis. • Dermatologic disorders and allergic conditions. • Corneal trauma and foreigon bodies.
- 16. MANIFESTATIONS AND DIAGNOSISAPPRAOCH History • Ocular symptoms: pain, redness, discharge, blurred vision, photophobia, coloured haloes, blepharospsm.. • Review of prior ocular history • Review of other medical problems. • Current ocular medications. • Medication allergies. Examination • Visual Acuity • External Examination • Slit-Lamp Biomicroscopy.
- 17. Diagnostic Tests Cultures andSmears indicated in: • Cases with acorneal infiltrate that is large and extends deep to the middle of the stroma, that is chronic in nature or unresponsive to broad spectrum A.B therapy. • Features suggestive of fungal, amœbic,or mycobacteria. • Smears may be helpful in cases of severe ulcerative keratitis or in cases with clinical features suggestive of fungal, amoebic,or mycobacterial infection. Corneal Biopsy indicated in: • Lack of response to treatment or if cultures have been negative on more than one occasion and the clinical picture continues to suggest strongly an infectious process.
- 18. TREATMENT • 1- Antibiotics:Initial empiric Topical • Are the preferred method of treatment in most cases. • Using a fluoroquinolone is effective. • Combination fortified-antibiotic therapy is an alternative to consider for severe infection. Tobramycin (14 mg/mL) 1 drop every hour alternating with fortified cefazolin (50 mg/mL) or vancomycin (50mg/mL) 1 drop every hour. • For severe cases, a loading dose every 5 to 15 • minutes for the first hour, followed by applications every 15 min to 1 hour around the clock. • For less severe cases, a regimen with less frequent dosing is appropriate.
- 19. 1- Antibiotics: Initialempiric Subconjunctival • Given when there is imminent scleral spread or perforation • One injection per day for 5 days. • helpful where there is imminent scleral spread or • perforation Systemic • Used when infectious has extended to adjacent tissues or when there is impending or frank perforation. • Gonococcal keratitis
- 20. TREATMENT 2- Modification ofTherapy • Regimen should be modified if the patient is not responding • to initial therapy or ulcer progress .according to culture and sensitivity. 3- Topical Cycloplegics 4- Corticosteroid Therapy • There is no conclusive scientific evidence that shows that steroids alter clinical outcome. • Infiltrate compromises the visual axis. To be on 2-3 days of treatment. 5- Follow-up Evaluation
- 21. Prevention and EarlyDetection • Screening of patient with high risk factors • Education on use of extended wear contact lens • Protective eye wear for work and sports • Treatment of ocular surface disease