Angle Closure Glaucoma

Angle Closure GlaucomaAcute angle-closure glaucoma causes pain and loss of vision.  It is an emergency condition because severe vision loss can occur quickly if the condition is left untreated.

Acute angle-closure glaucoma occurs when the internal drainage of the eye (called the angle) closes or is blocked causing sudden increased intraocular eye pressure that damages the optic nerve.

The optic nerve is a bundle of nerve fibers that transmit visual signals from the eye to the brain. Optic nerve damage can be stopped, but lost vision from the damage cannot be recovered. That is why it is important to receive emergency treatment as quickly as possible for acute angle-closure glaucoma.

Causes

There is fluid (aqueous humor) that is continually being produced from the ciliary body (located behind the iris) and is drained from the anterior chamber angle located in the front portion of the eye.

The function of this fluid is to supply nourishment and oxygen to parts of the eye and washout waste products such as macrophages (white blood cells) and other debris. The fluid also maintains the shape of the eyeball and regulates intraocular pressure.

Aqueous humor is drained out through a spongy tissue at the front of the eye called the trabecular meshwork (located in the anterior chamber angle) and then into a drainage canal.

Acute angle-closure glaucoma is a sudden blockage that prevents the drainage of aqueous humor. It can be caused by the iris adhering to the lens and blocking the drainage channel. It also can be brought on when the pupil dilates and causes the iris tissue to cover the trabecular meshwork.

In rare instances, some medications such as certain antihistamines, decongestants, benzodiazepines, SSRI antidepressants, anticonvulsants, and anticholinergics can cause pupil dilation that leads to acute angle-closure glaucoma in individuals whose drainage angles are extremely narrow.

An attack of acute angle-closure glaucoma caused by pressure from the blockage of aqueous humor causes acute eye pain. Other symptoms include severe headache, nausea or vomiting, extremely blurry vision, halos around lights, and redness of the white part of the eye.

If you have these symptoms seek immediate medical attention.

Treatment

Acute angle-closure glaucoma is a medical emergency so the first thing that will be done to treat it is to lower the eye pressure with eye drops that narrow the pupil to move the iris away from the eye’s drainage system, and medications that lower the amount of aqueous humor your eye makes.

Once the pressure has dropped sufficiently, laser surgery is performed to make a small opening in the iris so the aqueous humor can drain properly.

The laser is focused inside the eye to make an opening in the iris without making any incision in the cornea.

If the surgery is done soon after the first symptoms occur, it is usually all it takes to relieve the crisis and stop damage to the optic nerve. In a few cases additional types of eye drops and oral medication are needed to cure the problem.