What is usually prescribed for fungal infections of the eye?

Treatment of Fungal Eye Infections

The treatment of fungal eye infections depends critically on the anatomical location and causative organism, with topical natamycin being the first-line agent for filamentous fungal keratitis, topical amphotericin B for yeast keratitis, and systemic azoles (fluconazole or voriconazole) combined with intravitreal antifungals for endophthalmitis. 1, 2

Fungal Keratitis (Corneal Infections)

Filamentous Fungi (Fusarium, Aspergillus)

• Topical natamycin 5% is the preferred first-line treatment, instilled hourly or every 2 hours initially, then reduced to 6-8 times daily after 3-4 days 1, 2
• Continue therapy for 14-21 days or until resolution of active fungal keratitis, with gradual dosage reduction at 4-7 day intervals to ensure organism elimination 1
• Alternative topical agents include amphotericin B 0.15%-1% eye drops, clotrimazole 1%, miconazole 1%, or ketoconazole 2% 3
• Oral itraconazole may be added for deeper corneal layer penetration in resistant cases 3

Yeast Keratitis (Candida species)

• Topical amphotericin B is the first choice for yeast keratitis 2
• Topical azole formulations (clotrimazole, miconazole, ketoconazole) are effective alternatives 3, 2

Surgical Intervention for Keratitis

• Surgery is required if progression occurs despite medical therapy or if perforation is threatened 3
• Surgical options include debridement, lamellar keratectomy, conjunctival flap formation, or corneal grafting 3

Fungal Endophthalmitis

Candida Endophthalmitis

For fluconazole/voriconazole-susceptible isolates:

• Fluconazole 800 mg loading dose, then 400-800 mg daily OR voriconazole 400 mg IV twice daily for 2 doses, then 300 mg IV/oral twice daily 3
• Duration: at least 4-6 weeks, determined by repeated ophthalmological examinations showing resolution 3

For fluconazole/voriconazole-resistant isolates:

• Liposomal amphotericin B 3-5 mg/kg IV daily, with or without oral flucytosine 25 mg/kg four times daily 3

With macular involvement:

• Systemic therapy PLUS intravitreal injection of amphotericin B deoxycholate 5-10 μg/0.1 mL sterile water OR voriconazole 100 μg/0.1 mL 3

With vitritis:

• Systemic therapy PLUS intravitreal injection 3
• Vitrectomy should be considered to decrease organism burden and remove fungal abscesses inaccessible to systemic agents 3

Aspergillus Endophthalmitis

• Systemic amphotericin B and itraconazole penetrate vitreous and aqueous humor inadequately, making treatment often unsuccessful with systemic therapy alone 3
• Intravitreal amphotericin B 10 μg dose is required, usually after pars plana vitrectomy 3
• Vitrectomy is necessary for both diagnosis and management, in conjunction with intravitreal amphotericin B or amphotericin B irrigation 3

Superficial Fungal Infections

Fungal Blepharitis and Conjunctivitis

• Natamycin 5% applied 4-6 times daily is sufficient for less severe superficial infections 1
• Alternative topical agents include amphotericin B, clotrimazole, or ketoconazole 3

Scleral Abscesses

• Surgery combined with topical amphotericin B 3
• The necessity of systemic antifungal therapy is unclear for isolated scleral infections 3

Critical Management Principles

Diagnostic Requirements

• Diagnosis requires smear and culture of vitreous and/or aqueous humor for endophthalmitis 3
• Corneal scrapings with smear and culture are essential for keratitis 1, 2
• Determine in vitro antifungal activity against the responsible fungus whenever possible 1

Joint Decision-Making

• Decisions regarding antifungal treatment and surgical intervention must be made jointly by an ophthalmologist and infectious diseases physician 3
• The ophthalmologist determines the extent of ocular infection (chorioretinitis with or without macular involvement, with or without vitritis) 3

Common Pitfalls to Avoid

• Do not rely on systemic antifungals alone for endophthalmitis—poor penetration into vitreous and aqueous humor necessitates intravitreal therapy for sight-threatening infections 3
• Do not delay surgical intervention when medical therapy shows progression or perforation threatens 3
• Avoid premature discontinuation of therapy—gradual dosage reduction at 4-7 day intervals ensures organism elimination 1
• Do not assume natamycin effectiveness has been established for endophthalmitis—it is indicated only for keratitis, blepharitis, and conjunctivitis 1
• For Aspergillus infections, differentiate from other fungi (Pseudallescheria, dematiaceous fungi, Mucorales, Fusarium) as this alters antifungal choice 3