Lens implant: chance at beating lazy eye
By Lauran Neergaard, AP
August 6, 2008, 12:00 am TWN
WASHINGTON -- Dr. Paul Dougherty delicately slipped a tiny lens inside the right eye of 7-year-old Megan Garvin — a last-ditch shot at saving her sight in that eye.
The California girl last week became one of a small number of U.S. children to try an experimental surgery to prevent virtual blindness from lazy eye diagnosed too late, or too severe, for standard treatment.
The new approach: Implantable lenses, the same kind that nearsighted adults can have inserted for crisper vision — but that are not officially approved for use in children.
"Without this technology, we couldn't help her," says Dougherty, a prominent Los Angeles eye surgeon who invited The Associated Press to document Megan's surgery. "This would be written off as a blind eye."
Up to 5 percent of children in the U.S. have amblyopia, commonly called lazy eye, where one eye is so much stronger than the other that the brain learns to ignore the weaker eye. Untreated, the proper neural connections for vision don't form, eventually rendering that eye useless.
Catch it early — preferably by preschool — and it can be fairly easy to fix by patching over the strong eye, or using special drops in it, for several hours a day so that the brain is forced to use the weak eye. But the older the child is, the less effective the treatment — and by age 9, brain-eye connections are pretty well set.
The leading cause is eyes that are not in perfect alignment. But a big difference in focusing power also triggers amblyopia. That's what happened with the Garvin girl, who had near-perfect vision in one eye but the other was too nearsighted to even see the big E on the eye chart.
It is sneaky: children do not realize they are seeing clearly out of only one eye, and often will not squint or otherwise signal there is a problem. So Megan was fast passing the window to correct amblyopia when a kindergarten eye exam flagged a problem.
"She reads perfectly, she's a very normal active child," says her mother, Rosie Garvin. "If she would not have had that vision test, I would never have known."
Ophthalmologists called it one of the worst cases they had ever seen. Glasses were not doable: One side would have required a clear lens and the other a soda-bottle thickness, a prescription of minus 12 diopters. Her parents tried inserting a contact lens in the bad eye — getting her to roughly 20-60 vision in that eye, far from perfect but able to see blurrily while the good eye was patched.