Eye Center Finds Eye Drops To Treat Childhood Disorder Can Work As
Well As Patching the Eye
National Eye Institute (NEI) study, conducted at more than 40 sites
nationwide including Emory Eye Center, has found that atropine drops,
given once a day to treat amblyopia or lazy eye -- the most common cause
of visual impairment in children -- work as well as the standard treatment
of patching one eye. This research finding in the Amblyopia Treatment
Study may lead to better compliance with treatment and improved quality
of life in children with this eye disorder. These results appear in
the March issue of Archives of Ophthalmology.
After six months of treatment,
researchers found that the drug atropine, when placed in the unaffected
eye once a day, can work as well as eye patching and may encourage better
compliance. Compliance is an important factor in the success of amblyopia
therapy. Treatment should be started when the child is young, since
amblyopia is more effectively treated in children under seven years
of age. Timely and successful treatment for amblyopia in childhood can
prevent lifelong visual impairment.
"These results are encouraging
because in some patients with amblyopia, the drops are an attractive
alternative to patching therapy," says Scott Lambert, MD, a pediatric
ophthalmologist at Emory Eye Center and an investigator in the NEI study.
"The drops are certainly easier to administer than trying to keep a
patch on young patients who may attend daycare or who may be allergic
to the patch adhesive. Additionally, the drops are a good alternative
for older children who may have a sense of stigma with a patch," he
Amblyopia, or lazy eye, is
a condition of poor vision in an otherwise healthy eye because the brain
has learned to favor the other eye. Although the eye with amblyopia
looks normal, there is interference with normal visual processing that
limits the development of a portion of the brain responsible for vision.
The most common causes of amblyopia are misalignment of the eyes (crossed
eyes) or significant differences in refractive error, such as farsightedness
or nearsightedness, between the two eyes. Amblyopia usually begins in
infancy or childhood. It is estimated that as many as three percent
of children in the U.S. have some degree of vision impairment due to
Treatment for amblyopia is
most effective when started in young children less than seven years
old. Response to treatment in older children is much less effective.
Most eye care professionals treat amblyopia by placing an opaque adhesive
patch, or "eye bandage," on the skin to cover the unaffected eye. This
forces the child to use the eye with amblyopia, which stimulates vision
in the eye with amblyopia and helps the part of the brain that manages
vision to develop more completely.
However, many children do
not like the appearance of the eye patch and the accompanying social
and psychological stigma and will not fully cooperate, which can lead
to treatment failure. Also, patching forces a child to use an eye that
has poor vision, often making compliance difficult for active children.
Unless it is successfully treated in early childhood, amblyopia usually
persists into adulthood, and is the most common cause of monocular (one
eye) visual impairment among children and young and middle-aged adults.
Consequently, it is crucial for children to comply with treatment.
The atropine eye drop works
by temporarily blurring vision in the unaffected eye, thereby forcing
the eye with amblyopia to be used. This strengthens it and improves
vision. The advantage of atropine treatment is that the parent simply
places a drop in the child's eye once a day. With patching, the parent
must monitor the child wearing the patch for six or more hours each
day for many weeks or months.
In the Amblyopia Treatment
Study, 215 children were randomly assigned to receive patching, and
204 were assigned to receive atropine eye drops. Researchers found that
79 percent of those receiving the eye patch were treated successfully,
and that 74 percent of those receiving the atropine were treated successfully.
This difference is clinically insignificant. Although researchers found
that vision in the amblyopic eye improved faster in the patching group,
the difference in the two groups at six months was small and not significant.
"The daily burden to administer
treatment for amblyopia falls on the parent," said study chairman Michael
Repka, M.D., professor of ophthalmology and pediatrics at the Wilmer
Eye Institute of Johns Hopkins University School of Medicine in Baltimore.
"This study shows that one drop a day of atropine works as well as patching
the eye for some children with amblyopia. Since both patching and atropine
work equally well, the choice of treatment can be made by the eye care
professional in consultation with the parent."
The children who were treated
in this study will continue to be followed until April 2003, allowing
researchers to learn whether there is any longer term advantage to treating
amblyopia with either patching or atropine.
The study was conducted by
the Pediatric Eye Disease Investigator Group at 47 clinical sites throughout
North America. The study was funded by the\ National Eye Institute and
coordinated by the Jaeb Center for Health Research in Tampa, Florida,
and the Wilmer Eye Institute of Johns Hopkins University in Baltimore.
B-Roll available by calling
301-496-5248. Photos and other materials available in downloadable,
camera-ready format on the NEI website at http://www.nei.nih.gov/amblyopia
The NEI is part of the National
Institutes of Health (NIH) and 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. The NIH is an
agency of the US Department of Health and Human Services.