Mechanism

Acute angle-closure glaucoma is usually caused by failure of aqueous humor to pass through the pupil and drain out through the trabecular meshwork.

This can be caused by:

1. The iris being pushed forward against the trabecular meshwork
2. A pupil-block, whereby the aqueous fails to pass through the pupil

The result is often markedly raised intraocular pressure.

A glaucomatous optic neuropathy can follow, giving severe and permanent vision loss.