This document discusses fungal keratitis, including its pathogenesis, classification, predisposing factors, clinical features, investigations, treatment, and recent advances. Some key points: - Fungal keratitis is a major cause of corneal blindness in tropical areas and has a worse prognosis than bacterial keratitis due to delayed diagnosis and lack of effective antifungal agents. - It is commonly caused by trauma with plant materials and can lead to corneal perforation. Classification includes yeasts like Candida and filamentous fungi. - Clinical features include pain, discharge, ulcers with feathery edges, and satellite lesions. Diagnosis involves staining, cultures, and PCR of corneal scrapes. - Treatment

1. FUNGAL KERATITIS
MODERATOR: DR SWATI JAIN MA’AM
PRESENTED BY: DR VAIBHAV VISHAL

2. FUNGAL KERATITIS
 Mycotic keratitis is a major cause of corneal blindness,
especially in tropical and subtropical countries.
 The prognosis is markedly worse compared to bacterial
keratitis.
 Delayed diagnosis and scarcity of effective antifungal
agents are the major factors for poor outcome

3. PATHOGENESIS
 Often evolve insidiously
 Commonly followed by trauma with vegetative
materials
 Corneal perforation is common
 Visual prognosis is frequently poor

5. CLASSIFICATION
Fungi
Non Filamentous Yeast Candida
Filamentous
Septate
Non Pigmented
Fusarium, Aspergillus,
Penicillin
Pigmented
Clavuraia, Alternaria,
Cladosporum
Aseptate Rhizopus, Mucor

6. PREDISPOSING FACTORS
 Chronic ocular surface disease
 Long term use of topical steroids
 Contact lens use
 Systemic immunosuppression
 Diabetes
 Trauma
 Lasik or other eye surgeries

7. CLINICAL FEATURES
 SYMPTOMS:
1. Gradual onset and progressive
pain
2. Grittiness or foreign body
sensation
3. Photophobia
4. Blurred vision
5. Watery or mucopurulent
discharge

8. CLINICAL FEATURES
 Red Flags for Diagnosis
 Corneal ulcers unresponsive to broad
spectrum antibiotics
 Satellite lesions
 Scanty secretions in large ulcer

9. CLINICAL FEATURES
 Dry ulcer
 Elevated edges
 Rough texture
 Grey white color
 Feathery edged infiltrate
 Hypopyon

10. CLINICAL FEATURES
 Satellite Lesions
 Endothelial plaque
 Immune ring of Wessely

11. CLINICAL FEATURES
 Candida keratitis: Yellow-white densely suppurative
infiltrate
 Filamentous keratitis:
 Grey or yellow-white stromal infiltrates
 Fluffy margins
 Progressive infiltration
 Satellite lesions
 Feathery branch like extensions or ring shaped
infiltrates
 Rapid progression with necrosis and thinning
 Penetration of intact Descemet’s membrane

12. CLINICAL FEATURES
 Other features:
 Anterior uveitis
 Raised IOP
 Scleritis
 Sterile or infective endophthalmitis

13. INVESTIGATIONS
1. Staining:
1. KOH preparation with direct microscopy
is highly sensitive
2. Gram and Giemsa stains are 50%
sensitive
3. Other stains: Periodic acid Schiff,
Calcoflour white and methamine silver

14. INVESTIGATIONS
 Cultures:
 Corneal scrapes should be taken from the base of
the ulcer base
 Scrapes should be plated on
1. Saboroud Dextrose Agar (SDA)
2. Blood agar
3. Enrichment media

15. INVESTIGATIONS
 Polymerase Chain Reaction (PCR):
 Rapid
 Highly sensitive (90%)
 Current investigation of choice
 Corneal Biopsy:
 Indicated when ulcer shows no improvement in 3-4
days and no growth from scrapings after a week
 Anterior Chamber tap: indicated in resistant
cases with endothelial exudates
 Confocal microscopy: in vivo identification of
microorganism

16. TREATMENT
 General Measures: Hospital admission is usually required
 Removal of epithelium: enhance drug penetration
 Topical antifungals: should be given hourly for 48 hours then reduced as per
condition
Candida Filamentous
Amphoterecin B (0.15%)
Natamycin (5%)
Fluconazole (2%)
Clotrimazole (1%)
Voriconazole (1% or 2%)
Natamycin (5%)
Amphoterecin B (0.15%)
Miconazole (1%)
Voriconazole (1% or 2%)

17. TREATMENT
 Broad spectrum antibiotic: to prevent or address bacterial coinfection
 Cycloplegic
 Subconjunctival fluconazole 2% upto 1ml for 5 days can be administered for
severe cases
 Systemic antifungals: when lesion is near the limbus or endophthalmitis is
suspected
Drugs
Voriconazole 400mg BD D1 then 200mg
OD
Itraconazole 200mg OD
Fluconazole 200mg BD
Doxycycline 100mg BD (anticollagenase)

18. TREATMENT
 Perforation:
 Bandage contact lens with glue for smaller
perforations
 Penetrating keratoplasty or corneal patch graft may
be required for larger perforations
 Superficial Keratectomy : for debulking
 Therapeutic Keratoplasty: when medical
therapy is ineffective or following perforation
 Anterior Chamber Washout: can be done with
enlarging endothelial exudation

19. RECENT ADVANCES
 Confocal microscopy: In
vivo confocal microscopy (IVCM)
uses a series of pinhole apertures to
create optical sections of the cornea.
It generates images from the cornea
with a resolution of 1 μm, which is
enough to yield instant imaging of
organisms that are larger than a few
micrometre such
as Acanthamoeba cysts and fungal
hyphae.

20. RECENT ADVANCES
 Smartphone-based digital imaging:
Tissue samples obtained by
conventional corneal scraping were
stained and imaged using a smartphone
coupled with a compact pocket
magnifier and integrated light-emitting
diode assembly. Photographs of
multiple sections of slides were viewed
using smartphone screen and pinch-to-
zoom function.

21. ADVANCES IN MEDICAL MANAGEMENT
 Posaconazole: It is a new triazole, a synthetic structural analogue of itraconazole. The
mechanism of action involves blocking of the fungal cell wall ergosterol synthesis.In vitro and in
vivo studies have shown that it has broad-spectrum activity against
most Candida species, Cryptococcus neoformans, Aspergillus species, and zygomycetes.
 Echinocandins: It is a group of newer antifungals, which act by inhibiting the synthesis of 1,3-β-
d-glucan, leading to cell lysis due to increased permeability of the cell wall. Currently available
echinocandins comprise caspofungin, micafungin and anidulafungin.
 Nano particles for sustained antifungal drug delivery: Cell-penetrating peptides (CPPs) are short
peptide sequences that are able to transport molecules across the cell membrane. They are
employed to enhance extracellular and intracellular internalization of various biomolecules. This
led to an enhanced solubility of the drug in aqueous medium and increased cellular
penetrability of NTM.

22. ADVANCES IN SURGICAL MANAGEMENT
 Intrastromal voriconazole: Such a method of drug delivery overcomes a major limitation of
topical antifungal therapy, which is poor bioavailability of drugs in cases of deep-seated
fungal corneal ulcer. It provides a depot of drug, close to the ulcerated area, at a dose of 50
μg/0.1 ml in 5 divided doses, from where the drug is slowly released into the infected tissue.
Various studies in the literature have found targeted therapy with VCZ as an effective
approach for deep-seated recalcitrant fungal corneal infections, not responding to
conventional treatment modalities
 Intracameral amphotericin B: It is another approach that is being utilized for targeted drug
delivery. It is indicated when medical treatment with topical and systemic antifungal has
failed, especially in cases with deep mycosis, endothelial plaque and presence of hypopyon
and/or inflammation of the anterior chamber. The concentration injected, as described in
literature, ranges between 5 and 10 μg/0.1 ml.

23. ADVANCES IN SURGICAL MANAGEMENT
 Corneal collagen cross-linking (riboflavin with ultraviolet-A irradiation): CXL
may act in cases of mycotic keratitis by a direct antifungal effect and by
halting the ongoing melting, thus helping to avoid emergency keratoplasty.
 Rose Bengal photodynamic therapy: PDT involves the activation of
photosensitizers using light of varying wavelengths. The photosensitizer is
excited by the light and reacts with oxygen-generating ROS, which, in turn,
react with various intracellular components to cause cell death. Recently, in an
experimental study, Arboleda et al. have demonstrated RB PDT to be
successful in infectious keratitis. However, there are no clinical studies to date
to justify PDT with RB for treatment of fungal keratitis.

25. THANK YOU