It’s widely believed that children with a so-called lazy eye have to be treated quite early in life, before the brain’s ‘wiring’ becomes fixed. However, many children who are 7 years of age or older appear to respond to treatment for amblyopia, as the condition is called, according to a new study.

Nonetheless, earlier treatment may still be better.

Treatment of amblyopia relies on covering the unaffected eye, forcing the lazy eye to work and thus establish critical visual pathways in the brain. Since the brain becomes less flexible as a child grows older, treatment is usually started before 7 years of age.

Even so, approximately one quarter of patients aged 10 to 17 responded to treatment in a previous pilot study, run by the Pediatric Eye Disease Investigator Group. The group is now reporting results of a larger trial.

Dr. Mitchell M. Scheiman, at the Jaeb Center for Health Research in Tampa, Florida, and associates enrolled 507 patients with amblyopia from 49 locations. All the participants were provided with optimal optical correction and then randomly assigned to the amblyopia treatment group or a “control” group.

Those in the active treatment group were prescribed 2 to 6 hours per day of patching along with instructions to perform near visual activities while their good eye was covered. Patients who improved during treatment continued to be followed every 6 weeks for up to 24 weeks.

Among children 7 to 12 years old, more than half (53 percent) of those in the treatment group improved compared with 25 percent of the children in the control group, the team reports in the Archives of Ophthalmology.

A good response was less likely among 13- to 17-year-olds - 25 percent in the treatment group versus 23 percent in the control group. However, there was a significant difference among those who hadn’t been treated previously for amblyopia - 47 percent versus 20 percent

The authors are not making any recommendations for the treatment of amblyopia in older children until follow-up results show whether or not improvement is sustained after the treatment is discontinued.

Given the equivocal results, especially among those age 13 to 17, “the take-home lesson is that considering how difficult it is to treat older children for amblyopia, it is vitally important to identify and treat amblyopia early in life, well before age 7 years,” comments Dr. David G. Hunter, an ophthalmologist at Children’s Hospital in Boston, in a related editorial.

SOURCE: Archives of Ophthalmology, April 2005.