## **Core Concept**
Peripheral anterior synechiae (PAS) are a complication of acute angle-closure glaucoma, where the iris becomes adherent to the trabecular meshwork due to increased intraocular pressure (IOP) and ischemia. This condition results from the obstruction of the pupil, leading to a sudden increase in IOP.

## **Why the Correct Answer is Right**
The correct answer, **inferonasal quadrant**, is based on the fact that in acute angle-closure glaucoma, the peripheral anterior synechiae tend to form earliest in areas where the angle is more prone to closure and ischemia. The inferonasal quadrant is one of the common sites for PAS formation due to the anatomical configuration of the anterior chamber angle.

## **Why Each Wrong Option is Incorrect**
- **Option A:** The superotemporal quadrant is not the most common site for early formation of PAS. While PAS can occur here, it's not the earliest or most common location.
- **Option B:** The superior quadrant is a potential site for PAS, but not specifically known for the earliest formation compared to other areas like the inferonasal quadrant.
- **Option C:** The correct answer being the inferonasal quadrant makes this option incorrect by default.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in acute angle-closure glaucoma, prompt treatment is crucial to prevent complications such as peripheral anterior synechiae, which can lead to chronic angle-closure glaucoma and vision loss. Gonioscopy is a diagnostic tool that can help identify PAS and assess the anterior chamber angle.

## **Correct Answer:** . inferonasal quadrant