What is Acute Angle-Closure Glaucoma?

Acute angle-closure glaucoma is a potentially serious eye disorder in which fluid and pressure build up to dangerous levels in the eye. A person may experience sudden, severe pain in and behind the eyes, blurry vision, and nausea. The disorder can lead to permanent vision impairment or even blindness if it is not addressed and treated right away. Medications are provided orally and through eye drops to decrease intra-ocular pressure (IOP) and relieve acute pain. Most patients require surgery following emergency medical care to promote better drainage and prevent a recurring attack of acute angle-closure glaucoma.

A lubricating fluid called aqueous humor normally drains from the back of the eye through a series of canals collectively called the trabecular meshwork. Acute angle-closure glaucoma occurs when the angle between the iris and the trabecular meshwork is significantly narrowed, leading to a blockage in the canals. IOP develops because aqueous humor has no place to go; it continues to be produced and builds up behind the lens of the eye.

Acute angle-closure glaucoma is most likely to affect farsighted people and the elderly. Farsightedness is characterized by narrow angles between the iris and the ciliary body, the structure that produces aqueous humor. A narrower angle is more susceptible to closure from mild movements of the iris. As people age, the lenses in their eyes naturally enlarge and angles get shallower. In addition, acute angle-closure glaucoma is more common in women than men. Subtle congenital defects in the lens, iris, trabecular meshwork, or optic nerve can also increase a person's chances of developing problems.

In most cases, symptoms of eye pain, headache, and blurred vision develop within hours of acute angle-closure glaucoma onset. A person may become lightheaded, nauseous, and highly sensitive to light and motion. The affected eye may turn red, appear to be swollen, and produce excess tears. It is important to seek emergency care at the first signs of acute angle-closure glaucoma to prevent serious complications.

In the emergency room, a doctor can confirm the presence of IOP by inspecting the eye and asking about symptoms. A special exam called gonioscopy may be used to confirm that drainage angles are indeed closed. During gonioscopy, the doctor inserts a magnifying contact lens into the eye and inspects the trabecular meshwork with a specialized type of microscope called a slit lamp. Treatment decisions are made immediately following diagnostic tests.

Most patients are given eye drops, oral drugs, intravenous medications, or a combination of the three to quickly alleviate IOP. Corticosteroids and other drugs can help relieve eye inflammation and slow aqueous humor production. Once IOP is normalized, an optometrist can schedule a surgical procedure called laser peripheral iridotomy, usually to be performed within two days. A laser is used to burn a new pathway for aqueous humor drainage through the iris. Iridotomy is usually performed on both eyes, even when only one eye is affected, to decrease the chances of another episode.