Paterson left the Mount Sinai Medical Center in the afternoon but will have another procedure in a few days to prevent glaucoma from appearing in his right eye, said Dr. John Danias, an ophthalmologist who treated the governor.
"He should be able to resume his normal activities tomorrow," Danias said. "He was in very good condition after the laser, but you understand he had a hard night."
The governor went home to rest late in the afternoon, spokesman Errol Cockfield said.
Paterson remained conscious throughout the procedure, but his office said that "in an abundance of caution, the Senate majority leader and the Assembly speaker were advised of this pursuant to standard protocol." Majority Leader Joseph Bruno is next in line of succession.
Unlike the chronic form of glaucoma most prevalent in the U.S., angle-closure glaucoma is an agonizing condition that occurs when the passageway that normally allows fluid to drain freely from the eye suddenly becomes completely blocked.
The blockage leads to an immediate buildup in pressure within the eye - and to pain so severe that some people compare it to childbirth or passing a kidney stone.
"It's a real emergency event. It's like, 'Oh my God, I can't bear this intense pain,"' said Dr. Gregory Harmon, a Manhattan ophthalmologist and chairman of the Glaucoma Foundation.
The best treatment is a laser iridotomy, which creates a microscopic hole in the iris that lets fluid drain. The procedure takes only a few minutes, is relatively risk-free, and usually clears up the problem instantly, said Harmon, who was not involved in Paterson's care.
Aside from the pain, the buildup in pressure can also damage a person's optic nerve and cause blindness. That concern is secondary for the legally blind governor, who lost most of his sight after an infection as an infant.
Paterson is to undergo iridotomy on his right eye - the one he still has some vision in - in a few days. That's a common step taken to prevent the problem from recurring.
Paterson, 54, can see shapes and usually recognizes people as they approach. He can read for just a few minutes at a time, with the text held close to his face; usually his aides read to him. At a bill signing last week, Paterson put his nose to the bill to figure out where to sign.
The Democrat was sworn in March 17, days after former Gov. Eliot Spitzer resigned amid a prostitution scandal. He had served as Spitzer's lieutenant governor for 14 months. When he succeeded Spitzer, New York was left without a second-in-command; voters won't pick a new lieutenant governor until the next gubernatorial election in 2010.
People generally suffer acute glaucoma because of an anatomical quirk - the passageway to the drain in the front portion of their eye is too narrow.
Sometimes, the condition isn't a problem, but an attack can be brought on suddenly when a person's pupil dilates, either due to low light, medication or stress. The dilation can further constrict the narrow passage.
Dr. Andrew Prince, a Manhattan glaucoma specialist who hasn't treated the governor, said lasers have revolutionized treatment for the condition. Previously, surgeons would have needed to slice open Paterson's cornea to get to his iris, a procedure associated with hemorrhaging and infection that can lead to blindness.
"Now with the advent of lasers, the complication rate of laser iridotomy is quite minimal," Prince said. "It's probably one of the safest surgical procedures that we perform on the eye."
About 3 million Americans have glaucoma, and about half of them don't know it, according to the American Academy of Ophthalmology.
Only about 10 percent of those cases are acute glaucoma. The other 90 percent have open-angle glaucoma, which develops gradually, often with symptoms developing in late stages of the disease.
With open-angle glaucoma, the drains that allow fluid to leave the eye are open but aren't functioning well. Pressure builds up over time, rather than suddenly, so the condition often isn't painful, but it can still lead to damage of the optic nerve if left untreated.
