Anterior Chamber Angles Testing
- Mar 3
- 2 min read
The anterior chamber angle (also called the iridocorneal angle) is the angle formed between the cornea and the iris.
This angle contains the eye’s "drainage system" - the trabecular meshwork and the Schlemm’s canal. It is in this angle the fluid in the eye (called the aqueous humour) drains away.
Our eyes continually produce fluids, and this angle determines how well the fluid drains. When the angle is open, there is normal fluid drainage, hence the pressure within the eye, called the intraocular pressure (IOP), remains normal.
When the angle is narrow or closed, the drainage is slower than the production, which then leads to an increase in the IOP.
Elevated IOP can damage the optic nerve fibres, leading to glaucoma.
The Anterior Chamber Angle can be checked using gonioscopy, which is done by placing a special type of lens (after instilling anaesthetic drops) in contact with the cornea and observing the angle directly. Optical Coherence Tomography (OCT) can also be used as a less invasive method which is more comfortable for patients.
With a narrower angle, the risk of an angle-closure is higher, which can rapidly increase the eye pressure - an ocular emergency. When the angles are narrow, it can also cause a higher-then-normal eye pressure - or ocular hypertension. Both of these can lead to glaucoma.
Angle-Closure symptoms:
Severe eye pain
Red eye
Blurred vision
Seeing halos
Nausea/vomiting
One of the methods of managing narrow angles is Laser Peripheral Iridotomy (LPI), which is a preventative treatment where a laser creates a tiny hole in the iris to improve fluid drainage and lower eye pressure.
