Sep 19 2007
British researchers say youngsters may not need to wear an eye patch 12 hours a day, as is currently recommended, to treat the condition. Instead, wearing the patch just three to four hours a day over a period of three months may do the trick to improve sight, the new study suggests.
"Lengthy durations of daily patching, which are incredibly burdensome on the child and their parents, are clinically unnecessary," said study co-author Merrick J. Moseley, a senior lecturer in the Department of Optometry and Visual Science at City University in London, England.
His team reported its findings in the Sept. 13 online edition of the British Medical Journal.
Lazy eye, or amblyopia, is caused by a disturbance to the vision pathways between the eyes and the brain, and is associated with blurred vision or crossed eyes. Studies have shown that patching can improve vision.
Although prior findings have found that patch use 12 hours a day is no better than six hours a day, many doctors have continued to prescribe more than six hours of patching daily.
To find out how well patching worked, Moseley's team studied 80 3- to 8-year-olds with amblyopia. The children were told to wear a patch for either six or 12 hours a day. The youngsters were also electronically monitored to see how long they actually wore their eye patch.
The team found that children prescribed six hours of eye patching a day did just as well as those prescribed 12 hours a day. "Moreover, monitoring showed that children wear their patches only for about half the time that they are prescribed," Moseley said.
"Children who actually patched 3 to 6 hours each day did just as well as those who patched 6 to 12 hours each day," Moseley said. However, "those who patched under 3 hours a day did significantly less well than the rest," he added.
In addition, the researchers found that children under 4 years of age require significantly less patching than those over 4 years. "The findings did not vary depending on the type of amblyopia -- anisometropic, strabismic or combined," Moseley said.
"Patching is not better beyond 3 to 4 hours a day, particularly in the case of young children," Moseley said. "The findings should signal the end of the treatment strategy wherein children are prescribed lengthy patching regimens such as 'all waking hours,' which have previously found favor among many clinicians."
"This study is an eye opener," added Dr. Daniel J. Salchow, an assistant professor of ophthalmology and visual science and director of pediatric ophthalmology at Yale University School of Medicine. "The paper really tells you what you get for a dose of patching," he said.
"We know how to treat amblyopia," Salchow said. One of the biggest problems in treating lazy eye is getting children and parents to use the patch for the prescribed time, he noted. "But those who keep the patch on longer improve faster," he said.
Salchow said that he usually prescribes six hours a day or less of patching. "Unless it's a very strong amblyopia, very seldom do I prescribe 12 hours," he said.
But it's up to parents to make sure their child wears the patch, Salchow said. "If a parent says 'it's so hard for me to have the child wear the patch,' often the results we see are disappointing," he said.