Gancyclovir is used intravitreallyfor treatment of?
**Core Concept**
Ganciclovir is an antiviral medication that inhibits viral replication by selectively inhibiting viral DNA polymerase. It is used to treat various viral infections, including those caused by cytomegalovirus (CMV). In the context of intravitreal administration, ganciclovir is used to treat CMV retinitis, a serious viral infection that affects the retina.
**Why the Correct Answer is Right**
Intravitreal ganciclovir is used to treat CMV retinitis in immunocompromised patients, such as those with HIV/AIDS. The medication is administered directly into the vitreous humor, the clear gel-like substance that fills the center of the eyeball. Ganciclovir works by selectively inhibiting viral DNA polymerase, which is essential for the replication of CMV. This leads to the inhibition of viral replication and a reduction in the severity of the infection.
**Why Each Wrong Option is Incorrect**
* **Option A:** While ganciclovir is used to treat CMV infections, it is not typically used to treat bacterial or fungal infections.
* **Option B:** Topical administration of ganciclovir is not effective for treating CMV retinitis, as the medication needs to be administered directly into the vitreous humor to be effective.
* **Option D:** Oral administration of ganciclovir is not effective for treating CMV retinitis, as the medication needs to be administered directly into the vitreous humor to be effective.
**Clinical Pearl / High-Yield Fact**
Ganciclovir is a nucleoside analog that selectively inhibits viral DNA polymerase, making it an effective treatment for CMV infections. It is essential to note that intravitreal administration of ganciclovir is typically reserved for immunocompromised patients with CMV retinitis, as it can cause significant side effects, including retinal detachment and cataract formation.
**Correct Answer:** C. CMV retinitis