National trial shows older children benefit from treatment for childhood's most common eye disorder


Children's Hospital of Pittsburgh ophthalmologist co-chairs national trial

Surprising results from a nationwide clinical trial show that many children age seven through 17 with lazy eye, or amblyopia, may benefit from treatments that are more commonly used on younger children.

Amblyopia is a leading cause of vision impairment in children and usually begins in infancy or childhood.

Children's Hospital of Pittsburgh Chief of Ophthalmology Richard W. Hertle, MD, co-chaired the study, which showed that treatment improved the vision of many of the 507 older children with amblyopia studied at 49 eye centers nationwide. Previously, many eye care professionals thought that treating amblyopia in older children would be of little benefit.

The study results, funded by the National Eye Institute (NEI) of the National Institutes of Health (NIH), and coordinated by the Jaeb Center for Health Research in Tampa, FLA appears in the April issue of Archives of Ophthalmology.

Amblyopia is a condition resulting in poor vision in an otherwise healthy eye due to unequal or abnormal visual input while the brain is developing in infancy and childhood. The most common causes of amblyopia are crossed or wandering eyes (strabismus) or significant differences between the eyes in refractive error, i.e., astigmatism, farsightedness or nearsightedness.

Amblyopia affects as many as three percent of children in the U.S.

"This study shows how important it is to screen children of all ages for amblyopia." said Dr. Hertle. "Previously, patients were told there was nothing that could be done to help them. Now, there is something we can do and it has immediate results."

Children in the study were divided randomly into two groups. One group was fitted with new prescription glasses only. The other group was fitted with glasses as well an eye patch with near activities and/or special eye drops to limit use of the unaffected eye. The patching, near activities and eye drops force a child to use the eye with amblyopia. Patching was prescribed for periods of two to six hours daily, while the drop was administered daily for the children 7 to 12 years of age.

The study investigators set the standard for successful vision improvement in the amblyopic eye as the ability to read at least two more lines on a standard eye chart. Those investigators found that 53 percent of children ages 7 to 12 years who received both glasses and treatment with patches, near activity met this standard, while only 25 percent of those children in this age group who received glasses alone met the standard.

For children age 13 through 17 who were treated with both glasses and patches (these children did not get drops), 25 percent met the standard while 23 percent children of these ages who received only glasses met the standard.

The study also revealed that among children age 13 through 17 years who had not been previously treated for amblyopia, 47 percent of those who were treated with glasses, patching and near activities improved two lines or more compared with only 20 percent of those treated with glasses alone. Most children, including those who responded to treatment, were left with some visual impairment (i.e. did not obtain "20/20" vision.)

"These results are important. Dr. Hertle and colleagues have shown conclusively that traditional treatments for amblyopia will work for many older children," said Joel S. Schuman, MD, Eye and Ear Foundation Professor and Chairman of Ophthalmology, University of Pittsburgh School of Medicine and director of the University of Pittsburgh Medical Center (UPMC) Eye Center. "This is important because this disease has a high prevalence, with 2 to 3 percent of the general population have having amblyopia. Dr. Hertle and colleagues have demonstrated the effectiveness of treatment in a population previously thought to be untreatable."

It is not known, say the study authors, whether vision improvement will be sustained in these children once treatment is discontinued. The NEI is supporting a one-year follow-up study to determine the recurrence of amblyopic vision loss among the children who responded well to treatment, as well as many other clinical studies of amblyopia at eye centers nationwide.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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