From the News Desk of UC San Diego Health

Primary angle closure glaucoma (sometimes called acute glaucoma) occurs when the iris blocks drainage of the eye through the trabecular network, an area of tissue located around the cornea responsible for draining the aqueous humor — the transparent, watery fluid that fills the space in the front of the eyeball between the lens and cornea.

Primary angle closure glaucoma is less common than primary open-angle glaucoma, but more visually destructive. Treatment is typically either cataract extraction or laser iridotomy, which creates a drainage path. Laser iridotomy is also used to treat persons suspected of having primary angle closure in order to prevent the development of glaucoma, a condition in which the eye’s optic nerve is damaged, typically by fluid pressure buildup and, untreated, can result in permanent vision loss.

Primary angle closure glaucoma is more common among persons of Asian descent; and more common among women than men.

In a paper published in The Lancet, Chinese researchers conducted a very large, long-term randomized clinical trial to determine if laser iridotomy was an effective prophylactic for glaucoma. In an accompanying commentary by Robert Weinreb, MD, director of the Shiley Eye Institute at UC San Diego Health and a renowned glaucoma expert, describes the study’s value and findings (laser iridotomy decreases incidences of primary angle closure in eyes at risk, but only modestly) and the need for more expansive research involving other ethnic groups, for whom very little or no data exists.

— Scott LaFee