Nystatin Eye Drops Are Not Recommended for Fungal Eye Infections
Nystatin is not formulated as an ophthalmic eye drop preparation and should not be prescribed for fungal eye infections. The available evidence does not support nystatin drops for ocular fungal infections, and superior alternatives exist with established efficacy and safety profiles.
Why Nystatin Is Not Appropriate for Ocular Use
Nystatin lacks adequate corneal penetration due to its molecular weight and pharmacokinetic properties, making it ineffective for treating fungal keratitis or endophthalmitis when applied topically to the eye 1.
No standardized ophthalmic formulation exists for nystatin eye drops in clinical practice, and it has been studied only in experimental contexts such as corneal storage media, not for treating active infections 2.
Nystatin has been used successfully as a topical powder for burn wound fungal infections at concentrations of 6,000 units/g, but this application is entirely different from ocular use 3.
Recommended Alternatives for Fungal Eye Infections
For Candidal Endophthalmitis (Most Relevant to Systemic Guidelines)
For fluconazole/voriconazole-susceptible Candida isolates:
Systemic therapy with fluconazole (loading dose 800 mg, then 400-800 mg daily) OR voriconazole (loading dose 400 mg IV twice daily for 2 doses, then 300 mg IV or oral twice daily) is the primary treatment 4.
With macular involvement, add intravitreal injection of amphotericin B deoxycholate 5-10 μg/0.1 mL sterile water OR voriconazole 100 μg/0.1 mL to ensure rapid high-level antifungal activity 4.
Treatment duration should be at least 4-6 weeks, with final duration based on resolution of lesions determined by repeated ophthalmological examinations 4.
For Fungal Keratitis (Corneal Infections)
Topical natamycin is the most commonly used agent for fungal keratitis, as it provides better corneal penetration than nystatin 1.
Topical amphotericin B is another polyene option with established ophthalmic use 1.
Triazole antifungals are the agents of choice based on superior pharmacokinetic profiles and broader antifungal spectra, with topical administration being critical for achieving therapeutic corneal levels 1.
Newer formulations such as caspofungin-loaded in situ gelling preparations show promise for treating Candida keratitis, though these remain investigational 5.
Critical Clinical Considerations
All patients with candidemia require dilated retinal examination by an ophthalmologist within the first week of therapy (delayed until neutrophil recovery in neutropenic patients) to detect endophthalmitis 4.
Decisions regarding antifungal treatment and surgical intervention must be made jointly by an ophthalmologist and infectious diseases physician 4.
Early diagnosis is essential for preserving visual function, requiring clinical suspicion of fungal etiology and prompt collection of smears and cultures 1.
Vitrectomy should be considered for vitritis to decrease organism burden and remove fungal abscesses inaccessible to systemic agents 4.