Treating Amblyopia or Lazy Eye

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

Treatment improved the vision of many of the 507 older children with amblyopia studied at
49 eye centers. Previously, eye care professionals often thought that treating amblyopia in
older children would be of little benefit.

"Doctors can now feel confident that traditional treatments for amblyopia will work for
many older children," said Paul A. Sieving, M.D., Ph.D., director of the NEI. "This is
important because it is estimated that as many as three percent of children in the United
States have some degree of vision impairment due to amblyopia. Many of these children do
not receive treatment while they are young," he said.

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
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 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.

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. Despite the benefits of the treatment, most children,
including those who responded to treatment, were left with some visual impairment. They
did not obtain "20/20" vision.

Commented study co-chairman Mitchell M. Scheiman, O.D., Pennsylvania College of
Optometry, "This study shows that age alone should not be used as a factor to decide
whether or not to treat a child for amblyopia. The opportunity to treat amblyopia does not
end with the pre-school years."

Dr. Sieving also commented that the current study results are "a wonderful example of the
adaptability of the human visual system and brain. The NIH is exploring ways to take
advantage of this adaptability in order to better understand and treat vision problems and
other neurological conditions."

The National Eye Institute (NEI) a component of the National Institutes of Health is the
federal government's lead agency for vision research that leads to sight saving treatments
and plays a key role in reducing visual impairment and blindness. For more information,
visit the NEI Web site at www.nei.nih.gov/.