Which antifungal is used intravitreally?
**Core Concept**
Intravitreal antifungal agents are used to treat fungal infections within the eye, specifically in the vitreous humor. These medications must be able to penetrate the eye's barrier systems and target the fungal pathogens effectively.
**Why the Correct Answer is Right**
The correct answer is **Amphotericin B**, which is a polyene antifungal that can be used intravitreally to treat severe fungal endophthalmitis. Amphotericin B binds to ergosterol in the fungal cell membrane, causing a channel-mediated leakage of essential ions and leading to cell death. This mechanism of action is crucial for its effectiveness against a wide range of fungal species.
**Why Each Wrong Option is Incorrect**
**Option A:** Fluconazole is a triazole antifungal, primarily used orally or topically for superficial fungal infections, making it unsuitable for intravitreal use.
**Option B:** Voriconazole is another triazole antifungal, often used for systemic and ocular fungal infections, but it is not typically administered intravitreally due to its formulation and potential toxicity.
**Option C:** Griseofulvin is an antifungal that targets fungal microtubules, but it is not used intravitreally due to its poor penetration into the eye and potential toxicity.
**Clinical Pearl / High-Yield Fact**
When considering antifungal therapy for ocular infections, it is essential to remember that the choice of medication depends on the severity and location of the infection, as well as the patient's overall health and potential allergic reactions.
**Correct Answer: D. Amphotericin B.**