**Core Concept:**
Secondary glaucoma arises due to an increase in intraocular pressure (IOP) that occurs after initial damage to the eye's structures. Corneal perforation can lead to secondary glaucoma as it results in an imbalance between aqueous humor production and outflow, causing a rise in IOP.

**Why the Correct Answer is Right:**

The correct answer is D (aqueous humor outflow obstruction), as corneal perforation can result in an obstruction of the aqueous humor outflow pathway. This is due to the following reasons:

1. Peripheral anterior chamber shallowing: With corneal perforation, the aqueous humor production remains the same, but the normal anterior chamber depth is disrupted. This leads to peripheral anterior chamber shallowing, causing an increase in IOP.
2. Obliteration of the trabecular meshwork: In case of corneal perforation, the trabecular meshwork, which is responsible for aqueous humor outflow, gets obliterated by inflammatory cells and debris. This obstructs the outflow pathway, causing secondary glaucoma.

**Why Each Wrong Option is Incorrect:**

A. Angle closure glaucoma (option A) is caused by the closure of the angle between the cornea and sclera, leading to a blockage of aqueous humor outflow. This is not the case in the given scenario, as the obstruction is due to peripheral anterior chamber shallowing and obliteration of the trabecular meshwork, rather than angle closure.

B. Primary open angle glaucoma (option B) occurs due to an increased aqueous humor production or decreased aqueous humor outflow. In this case, the increased IOP is due to aqueous humor outflow obstruction, not increased production.

C. Normal tension glaucoma (option C) is a term that refers to glaucoma with an IOP within the normal range (12-21 mmHg). In this case, the increased IOP is not related to the normal IOP range, but rather the obstruction of aqueous humor outflow due to peripheral anterior chamber shallowing and obliteration of the trabecular meshwork.

**Clinical Pearl:**
Corneal perforation can lead to a condition known as "secondary glaucoma" due to aqueous humor outflow obstruction, specifically peripheral anterior chamber shallowing and obliteration of the trabecular meshwork. This can result in increased intraocular pressure and potential vision loss if not promptly treated.