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Fungal corneal-ulcer-final
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- 2. • Chairman :Dr. Md. Abdul Quader Professor of Cornea , NIO&H • Moderator : Dr. Tania Hussain Sharmee Jr. Consultant. of Cornea , NIO&H • Presenter : Dr. Mahamud Adnan DO Resident, NIO&H
- 3. Introduction EPIDEMIOLOGY : • Worldwide,fungal keratitis is a significant cause of ocular morbidity and unilateral blindness. • Fungal corneal ulcers accounts 36% in Bangladesh. • Following ocular trauma from vegetable matter; thus, agricultural workers are at greater risk. • Rural > Urban • More common in tropical regions. • More common in males than in females
- 4. • Ulcer : “Is a local defect ,or excavation, of the surface of an organ or tissue that is produced by the sloughing (shedding) of inflamed necrotic tissue “ (Ref. Robins pathology ) • Corneal ulcer : Refers to tissue excavation associated with an epithelial defect , usually with infiltration and necrosis. • Corneal keratitis : Presence of tissue inflammation with or without epithelial defect.
- 5. Etiological classification ofcorneal Ulcer • Bacterial • Fungal • Viral • Protozoal • Helminthic Infective :
- 6. Fungi Causing keratitis 1.Filamentous - a. Septated : Nonpigmented hyphae (hyaline) • Fusarium species • Aspergillus • Trichophyton Pigmented hyphae(dimorphic) • Alternaria • Curvularia • Histoplasma b.Nonseptated : • Mucor species • Rhizopous species
- 7. Fungi Causing keratitis(cont) 2. Yeast : Candida species • Trichosporon • Cryptococcus
- 8. Release of matrixmetalloproteinase & corneal necrosis Recruitment of inflammatory cell from tear & limbal vessel Invade & proliferate in corneal stroma release cytokines & chemokine Pathogens adhere to cornea Micro trauma and breach in the integrity of the corneal epithelium Pathogenesis
- 9. Risk Factors • Trauma •Chronic ocular surface disease • Topical medications (long term use of corticosteroid) • Contact lens wear • Immunosupression & diabetes • Corneal surgery ( penetrating keratoplasty , LASIK, radial keratotomy )
- 10. History • Recent oculartrauma • Contact lens wear • Use of ocular medications • Recent ocular surgery • Previous ocular disease • Systemic illness : Diabetes Immunosuppression
- 11. Clinical Features Symptoms : •Gradual onset of pain • Grittiness • Photophobia • Blurred vision • Watery or muco-purulent discharge
- 12. Signs : • Grayor Yellow – white stromal infiltration • Progressive Infiltration • Satellite lesions • Feathery branch or Ring shaped infiltration • Elevated edges • Progressive necrosis and thinning
- 13. Figure : showing(B) filamentous keratitis with fluffy edges , epithelial defect and folds in Descemet membrane (C)showing satellite lesions
- 14. Figure : Showingring infiltration, with satellite lesions
- 15. Signs (cont) : •Anterior uveitis • Hypopyon • Endothelial plaque • Raised IOP • Scleritis • Sterile or infective endophthalmitis
- 16. Differential diagnosis • Bacterialcorneal ulcer • Viral (herpetic) keratitis • Acanthamoeba keratitis
- 17. Investigations (Microbiological) 1. Cornealscraping Staining Culture 2. Corneal biopsy Corneal smear for staining Culture Histopathology
- 18. Corneal Scraping &Staining • KOH wet mount preparation • Gram stain • Giemsa stain • Periodic acid-Schiff stain • Calcofluor white stain • Methenamine silver stain
- 19. Scraping Procedure • Informedconsent • Topical anesthesia • Instrument: no. 15 blade, bent 21 G needle or Kimura spatula • Site: floor and margin of ulcer • Under slit lamp or operating microscope.
- 21. KOH preparation technique •After obtaining specimen: 1. Place specimen on a clean slide. 2. Add a drop of 10% KOH to the specimen. 3. Cover the specimen with a cover slip, being careful to avoid air bubbles.
- 22. KOH preparation technique(cont) 4.Incubate for 5-10 minutes at room temperature. 5. Examine saline wet mount with 10x and 40x objective to identify any budding yeast, pseudohyphae, organisms, or cells. 6. Examine KOH mount with 10x for yeast pseudohyphae and fungal hyphal filaments.
- 23. Culture Media • Sabourauddextrose agar media - White mycelium , black spore - Growth with cream colonies • Blood agar media • Brain–heart infusion media
- 24. Corneal Biopsy Indication : •Absence of clinical improvement after 3-4 days • Failure to identify organism Repeated smear examination Repeated culture of corneal scraping • Deeply seated keratitis • Intrastromal abscess Smear examination Culture Histopathology
- 25. Newer Diagnostic Modalities •Polymerase chain reaction - Rapid and highly sensitive • Anterior chamber tap - In resistant cases • Confocal microscopy - Permits identification of organism in vivo
- 26. Treatment 1. General measures: Hospitalizationfor – - Aggressive disease. - If involving an only eye. - If patient unable to self administer treatment. 2. Medical Therapy 3. Surgical Therapy
- 27. Antifungal agents Four groupof antifungal drugs - 1. Polyenes • Amphotericin B 0.15% • Natamycin 5% 2. Azoles • Econazole 2% • Miconazole 1% • Ketoconazole • Fluconazole 0.2% • Itraconazole 1% • Voriconazole 1% 3. Pyrimidine • 5-Fluorocytosine 4. Echinocandins • Caspofungin 0.5% • Micafungin 0.1%
- 28. Medical Therapy 1.Topical antifungals: •Clinically initial drug of choice is natamycin 5% suspension particularly for filamentous keratitis and for yeast keratitis. • Amphitericin-B 0.15% for yeast keratitis, also for filamentous keratitis caused by Aspergillus species. • Topical voriconazole 1% for non responding traditional treatment.
- 29. Medical Therapy(cont) Dose: • Initiallyone hourly round the clock until signs of healing/regression then tapered and if responding continue treatment • Length of treatment: Until healing of ulcer (at least 12 weeks) 2. Systemic Antifungals : • Indicated in severe keratitis, scleritis, lesions near limbus or suspected endophthalmitis
- 30. Medical therapy(cont) • Optionsinclude • Oral ketoconazole 200 mg twice daily for severe filamentous and yeast keratitis • Oral fluconazole 200 mg twice daily for severe yeast keratitis • Oral itraconazole 200 mg once daily for aspergillus species • Oral voriconazole 400 mg twice daily for broad spectrum coverage
- 31. Medical Therapy(cont) 3. Broadspectrum antibiotics: if bacterial co- infection present 4. Cycloplegia: to reduce pain and to prevent formation of posterior synechia 5. IOP should be monitored by Non-contact or digital tonometry or tonopen 6. Subconjunctival fluconazole (In severe cases ) 7. Tetaracycline (Doxycycline, in significant corneal thinning due to its anticollagenase effect )
- 32. Surgical Therapy 1. Therapeuticscraping/Debulking (superficial keratectomy): Done everyday or every alternate day to reduce number of organisms , necrotic material & to enhance penetration of topical antifungal drugs. 2. Conjunctival Flap
- 33. Surgical Therapy(cont.) 3. N-butylcyanoacrylate tissue adhesive and bandage contact lens to prevent or need for corneal transplant in severe thinning & perforation(<2 mm) 4. Anterior chamber washout with intracameral antifungal injection in unresponsive case for stable corneal infiltrate but enlarging endothelial exudation
- 34. Surgical Therapy(cont.) 5. Therapeutickeratoplasty (penetrating/deep anterior lamellar) : when medical therapy ineffective or following perforation or recurrence.
- 35. Sequel & Complication •Corneal Scaring (opacification) • Descemetocele • Secondary glaucoma • Perforation • Pseudo cornea • Anterior staphyloma • Endophthalmitis
- 36. Prognosis • Depends onsize and depth of lesion and causative organism • Small superficial lesion respond to topical therapy • Deep stromal infection , concomitant scleritis and intraocular involvement are difficult to eradicate
- 37. Prognosis (cont.) • Threefactors associated with treatment failure: large ulcer size(8-12 mm), presence of hypopeon and aspergillus organism • Surgical therapy successful when medical treatment fails.
- 38. Take Home Message •Diagnosis & treatment of fungal keratitis is challenging. • Lab. Diagnosis helps to correct the diagnosis. • Early diagnosis and proper management plan can save valuable vision of the patient.