TUESDAY, Nov. 2, 2004 (HealthDayNews) -- A new study offers good news for parents who have trouble remembering to treat their children every day for what's known as "lazy eye."
Two weekend doses of eye drops are just as effective as -- and easier to remember than -- daily treatments for the condition, which is medically known as amblyopia, the researchers found.
"I think this is going to give doctors another option," said Dr. Michael Repka, lead author of the study and a pediatric ophthalmologist at Johns Hopkins University Children's Center. The study, published in the November issue of the journal Ophthalmology, was conducted at 30 clinical sites.
Amblyopia affects about 2 percent of children, according to the American Academy of Pediatrics. Among the causes are crossed eyes, droopy eyelids, cataracts, and refractive errors such as farsightedness and nearsightedness. Often, a child will have different refractive errors in the two eyes, Repka said, and the eye with the greatest refractive error develops ambylopia as the stronger eye takes over.
Doctors will prescribe atropine drops, placed in the stronger eye to temporarily blur the vision, forcing the child to use the lazy eye. Or they might recommend patching the stronger eye so the child must rely on the eye with amblyopia.
In the study, Repka and his colleagues assigned 168 children up to age 7 with moderate amblyopia to get atropine eye drops, a common treatment, either daily or only on Saturdays and Sundays. At the start, the children's vision in the amblyopic eye ranged from 20/40 to 20/80. Acuity of 20/20 is termed normal.
Four months after the study began, children on both treatment regimens were able to read an average of 2.3 lines higher on a standard eye chart, reflecting effectiveness. Put another way, the average visual acuity in the weaker eye went from about 20/63 to 20/32, Repka said.
Forty-seven percent of the children getting daily drops and 53 percent of those getting weekend drops had vision in the lazy eye improve to normal levels (defined for the study as 20/25 or better) after four months.
The level of improvement found in the atropine study is similar to what is achieved with eye patching, Repka said. His previous research suggests that the duration of daily eye patching may be reduced with no decline in improvement. In one study, Repka's team compared children who wore a patch for six hours to those who wore one for two hours daily. "We found those groups did identically as well," he said.
In the wake of the patching study, and some work by other researchers suggesting that fewer doses of atropine might be effective, Repka's team, the Pediatric Eye Disease Investigative Group, decided to see whether two doses a week would achieve the same result as daily doses.
Typically, treatment for ambylopia continues for about two years or more, Repka said.
The study will change the status quo of ambylopia treatment, according to Repka and another expert, Dr. Richard Grostern, an assistant professor of ophthalmology at Rush Medical College, who is familiar with the new study. "I would imagine this will change clinical practice," Grostern said.
Grostern said he will definitely consider the shorter regimen for his patients.
To learn more about amblyopia, visit the National Eye Institute.