For adults, the procedure known as filtration surgery involves creating a drainage hole in the wall of the eye to relieve the pressure within the eye that characterizes glaucoma. The hole is covered by a flap of tissue that is held in place by several sutures. Eye surgeons then control drainage by cutting the sutures one at a time over a period of several weeks, using an in-office laser. The procedure has a 90 percent success rate.
For children, however, filtration surgery has had several drawbacks. Surgeons have faced challenges in moderating the rate of drainage in young patients' eyes because most children cannot sit still long enough for the meticulous removal of sutures. Ophthalmologists traditionally have used only one suture to close the flap, and hoped that the rapid decrease in pressure did not result in bleeding inside the eye.
A new ocular probe invented by Lynch can deliver laser energy from a portable unit the size of an attaché case. Ophthalmologists now are able to carry the laser into an operating room, where a child can be sedated and the gradual process of loosening the flaps can proceed.
The other obstacle surgeons have faced in pediatric filtration surgery -- excessive scarring -- has been eliminated by the development of topical medication toxic to scar tissue cells.
"When I came to Emory six years ago, the standard procedure for children who needed a glaucoma operation was cryosurgery," said Lynch, who is associate professor of ophthalmology at the School of Medicine. But that procedure only yielded a 10 percent to 20 percent success rate.
"We now have a 75 percent success rate with the filtering operation, as well as a low rate of hypotony (which occurs when pressure within the eye becomes too low)," said Lynch. More than 40 children have been treated with the new procedure at Emory.
Glaucoma affects one in 10,000 children in the United States.
-- Lorri Preston