**Core Concept**
Secondary glaucoma in the context of herpes zoster ophthalmicus (HZO) refers to an increase in intraocular pressure (IOP) that occurs as a complication of HZO. This phenomenon is primarily associated with the inflammatory response and the subsequent damage to the trabecular meshwork.

**Why the Correct Answer is Right**
The correct answer is due to the inflammatory destruction of the trabecular meshwork by the herpes zoster virus. The virus causes an intense inflammatory response in the anterior segment of the eye, leading to the destruction of the trabecular meshwork, the primary site of aqueous humor outflow. This results in an accumulation of aqueous humor within the eye, causing an increase in IOP.

**Why Each Wrong Option is Incorrect**
* **Option A:** Corneal edema is not the primary cause of secondary glaucoma in HZO. While corneal edema can contribute to increased IOP, it is not the direct cause of secondary glaucoma in this context.
* **Option B:** Uveitis is a complication of HZO, but it is not the primary cause of secondary glaucoma. Uveitis can contribute to increased IOP, but it is not the direct cause of secondary glaucoma in this context.
* **Option D:** Iris ischemia is a complication of HZO, but it is not the primary cause of secondary glaucoma. Iris ischemia can contribute to increased IOP, but it is not the direct cause of secondary glaucoma in this context.

**Clinical Pearl / High-Yield Fact**
Early recognition and treatment of HZO are crucial to prevent complications such as secondary glaucoma. Prompt initiation of antiviral therapy and corticosteroids can help reduce the risk of secondary glaucoma and other complications.

**Correct Answer: C. Inflammatory destruction of the trabecular meshwork.**