Researchers at the University of Minnesota participated in a nationwide clinical trial that determined that many children ages seven through 17 with amblyopia ( lazy eye ) may benefit from treatments that are more commonly used on younger children.
The study, the first large sample to show effective treatment for this eye condition, has been published in Archives of Ophthalmology.
Treatments for amblyopia include glasses, patching, and near work, which trains the eye to see better.
Treatment improved the vision of many of the 507 older children with amblyopia studied at 49 eye centers. The study investigators found that 53 percent of children age seven through 12 years who received treatment successfully improved their vision, compared with 25 percent of those children who did not receive treatment. Previously, eye care professionals often thought that treating amblyopia in older children would be of little benefit.
Traditional treatments for amblyopia will work for many older children, said Gail Summers, at the University of Minnesota.
Co-Investigator Stephen Christiansen, explained, This is important news because an estimated 3 percent of children in the United States have some degree of vision impairment due to amblyopia, and many of these children do not receive treatment while they are young.
Amblyopia is a leading cause of vision impairment in children and usually begins in infancy or childhood. It 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 eye ( strabismus ) or significant differences between the eyes in refractive error, such as astigmatism, farsightedness, or nearsightedness.
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 as an eye patch, or the eye patch along with special eye drops, to limit use of the unaffected eye. These children were also asked to perform near vision activities. The patching, near vision 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 eye drops were administered daily for the children seven though 12 years of age.
The study investigators defined successful vision improvement as the ability to read ( with the eye with amblyopia ) at least two more lines on a standard eye chart. The study investigators found that 53 percent of children age seven through 12 years who received both glasses and treatment with patches, eye drops, and 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 years who were treated with both glasses and patches ( these children did not get drops ), 25 percent met the standard while 23 percent of children of these ages who received only glasses met the standard.
Source: University of Minnesota, 2005