Study reveals eye drops work as well as eye patches to treat childhood eye disorder
A drug similar to the eye drops used to dilate patients eyes during an eye exam has the power to successfully treat a common childhood eye disorder called amblyopia (am-blee-OH-peeh-yah), or lazy eye. Amblyopia is the most common form of vision impairment in children. In the past standard treatment has been the use of an eye patch. However, new research now shows that eye drops work as well as patches. OHSU's Casey Eye Institute took part in the national clinical trial on the treatment of amblyopia. The results are printed in the March issue of Archives of Ophthalmology.
"The successful use of eye drops to treat amblyopia is considered quite a significant finding. This is due to the fact that getting young children to wear an eye patch for a period of weeks or months can be challenging. This therapy puts greater control in the parent's hands," said David Wheeler, M.D., Oregon's principal investigator for the clinical trial and an assistant professor of ophthalmology in OHSU's School of Medicine.
Ambylopia is characterized by poor vision in one of the eyes because the brain has learned to favor the other eye. The most common causes are misalignment (or wandering) of an eye, or significant nearsightedness or farsightedness in one eye. The disorder always begins in childhood when visual development is occurring. Treatment is frequently more effective when the condition is caught within the first few years of life.
Both patches and the newer drug therapy work by limiting the child's reliance on his/her stronger eye. Patients treated in the traditional manner are asked to wear a patch over their more effective, stronger eye for hours at a time. This teaches the brain to rely more on the weaker eye. The drug, called atropine, works in a similar way. When placed in the unaffected eye daily, the drug causes temporary blurriness, forcing the child to rely on the affected eye.
For the parents of 7-year-old Nikolas Scymanski, the eye drops have been quite helpful in restoring their son's vision. Nikolas was diagnosed with amblyopia two years ago when his parents noticed that his right eye was wandering. Now his vision is much improved, and he continues to do well.
Nikolas' mother is pleased that her son had the opportunity to receive eye drops instead of wearing an eye patch for extended periods of time. "I think the eye patch would have been much harder to deal with," said Lori Scymanski. "For us, this was the best route to go."
In all, 419 patients from across the country took part in the trial. A total of 215 children were treated with patches and 204 received atropine drops. According to study results six months following their initial treatment, 74 percent of patients treated with eye drops had substantial improvement in their weaker eye. That compares to a 79 percent success rate for patches. This difference between groups was not statistically significant.
"This new study found that atropine eye drops had a higher acceptance rate and better compliance by children and their parents than did patching. This may well become the new standard of treatment for some forms of amblyopia," said Paul A. Sieving, M.D., Ph.D., director of the National Eye Institute, the component of the National Institutes of Health that funded the study.
The children involved in this trial will be followed until April 2003, allowing doctors to determine whether there is any longer-term advantage to treating amblyopia with either patches or eye drops.
A total of 47 clinical sites throughout North America were involved in the drug trial. The Jaeb Center for Health Research in Tampa, Fla. and the Wilmer Eye Institute of Johns Hopkins University in Baltimore, Md. coordinated the study.