Atropine as effective as patch for moderate amblyopia, study shows

With drops instead of a patch, pediatric ophthalmologists envision an improved quality of life for children with amblyopia and their parents.

Issue: April 15, 2002

BETHESDA, Md. — Atropine sulfate drops were found to be a comparable method of therapy to eye patching for the treatment of moderate amblyopia in children, according to new data from the Amblyopia Treatment Study.

“This new information is important because it provides an effective alternative treatment that helps to prevent permanent vision impairment for children with amblyopia,” said Paul A. Sieving, MD, PhD, director of the National Eye Institute (NEI).

The NEI helped to fund the multicenter, randomized trial. The study was published in Archives of Ophthalmology.

The standard treatment of amblyopia in children has been occlusion therapy, which consists of patching the normal eye during daily waking hours so that the amblyopic eye is forced to perform normal visual function.

This approach, however, has a low rate of compliance. Compliance ranges from 49% to 87% among patients with amblyopia, who dislike the visual appearance of the patch and the feel of it on their face, as well as the social and psychological implications of having a so-called “handicap.”

“Children usually don’t like this treatment because the patch is not aesthetically pleasing to them,” Robert S. Gold, MD, said in an interview with Ocular Surgery News. “There are quality-of-life issues with occlusion therapy … like teasing by other children.”

The study found that atropine drops had a greater acceptance and more compliance by children and their patients than patches did, even though patches provided slightly quicker resolution of amblyopia.

“We found that atropine drops worked as well and had a higher acceptance rate,” Dr. Sieving said. “Therefore, atropine may become a new standard treatment for some forms of amblyopia.”

Atropine re-evaluated

According to the study, atropine has been known as an alternative treatment to the eye patch for nearly 100 years. It has been a second choice when occlusion therapy is not shown to be an effective treatment.

In 1997, physicians from the Pediatric Eye Disease Investigator Group (PEDIG), which conducted the Amblyopia Treatment Study, found that only 3% of investigators were prescribing atropine as their primary treatment modality.

In contrast, nearly 97% of them were prescribing occlusion therapy despite findings that atropine worked well, the authors of the study said.

According to Dr. Sieving, a definitive study was needed to compare the outcomes of the eye patch to atropine, and to determine if new, updated practice guidelines were needed for the treatment of amblyopia.

Study design

---The standard treatment of amblyopia in children has been occlusion therapy, which consists of patching the normal eye during daily waking hours so that the amblyopic eye is forced to perform normal visual function.
Photograph courtesy of the National Eye Institute, National Institutes of Health.

Between April 1999 and April 2001, 419 boys and girls up to age 7 were recruited for the study. The study was carried out across 47 clinical centers and universities nationwide.

According to the study authors, patients were selected based upon their amblyopia, ranging from 20/40 to 20/100. To be included, patients’ normal or “sound” eye had to have a visual acuity of 20/40 or better.

Additionally, all patients had to wear glasses for at least 4 months before they were eligible for the study. A presence or history of amblyopia, triggered by strabismus or anisometropia or both, was also required.

After selection, 204 patients were randomized to atropine, while 215 patients received occlusion therapy with an eye patch.

All parents of patients were advised to follow specific protocol regarding their child’s treatment. Children with atropine therapy were given one drop of atropine sulfate (1%) in their sound eye each day. This was to obscure vision in this eye so the diseased eye would learn to function. Children were advised to wear a hat and sunglasses when in the sun.

Children with occlusion therapy were instructed to wear the patch over their sound eye for at least 6 hours a day, or during all hours when not sleeping.

Follow-up examinations varied for both groups. However, both the atropine and the occlusion groups were seen at 5 weeks, 16 weeks and finally 6 months after the study began. At the 5-week point, parents of all patients were given a questionnaire to assess the quality-of-life effects of the amblyopia therapy on their child and themselves. At the 6-month outcome examination, patients were tested to see if visual acuity had improved.

Similar visual result

According to the study, “visual differences in the amblyopic eye between treatment groups were small and inconsequential.” However, at this point, a greater initial improvement in visual acuity was achieved with patching than with atropine, the study authors noted.

This difference in visual acuity was approximately one-third of a line on a Snellen chart. At the 5-week visit, visual acuity improved by an average of 2.22 lines in patients with eye patches, whereas an improvement of 1.37 lines was seen patients with atropine. By 6 months, the difference had narrowed and resulted in a mean of a 2.3-line improvement for both study groups.

“The 6-month period showed there was no statistical difference in visual acuity, although there was a pretty large gap concerning quality of life,” Dr. Gold said.

A patient’s quality of life was assessed from the response of parent questionnaires. According to the study, treatment was “well tolerated” by both study groups. However, when testing quality of life, scores were consistently poorer for the patch group, compared with the atropine group.

Increased quality-of-life, reduced cost

The study noted, “in all areas of questioning, the occlusion group got consistently lower scores for adverse effects, difficulty with compliance and social stigma.”

Patients with children wearing patches rated adverse effects to the therapy, like rash and skin irritation, as a disturbance significant of P = .002, in relation to the atropine group. Additionally, these patients also rated the difficulty with compliance as significant of P < .001, and the social stigma attached to the patch as hindering social situations by P < .001.

“The burden of daily treatment usually falls on the parent. However, with atropine, parents found better compliance and easy administration,” Dr. Gold said.

The study also noted that atropine was cost-effective in comparison to occlusion therapy. Atropine was estimated to cost around $10 for over 6 months, whereas the eye patch would cost nearly $100 for this same length of time, the authors wrote.

In addition, about 25% of atropine patients will need to wear glasses with a plano spectacle lens, due to an inadequate response to atropine alone. However, this added correction would cost $50 plus the fee of atropine drops — still less than occlusion therapy, study authors noted.

Dr. Gold said the results of this study allow the eye care professional and parent to decide which form of treatment is right for the individual child, considering that both the eye patch and atropine are effective methods of treatment for moderate amblyopia. According to Dr. Gold, most pediatric ophthalmologists still use patching as their first-line therapy for amblyopia.

“Atropine is certainly an alternative therapy for amblyopia and should be strongly considered in certain situations. Long-term results will prove to solidify the significance of this information,” Dr. Gold said.

For Your Information:

Robert S. Gold, MD, can be reached at 225 W. State Rd. 434, Suite 111, Longwood, FL 32750; (407) 767-6411; fax: (407) 767-8160; e-mail: rsgeye@aol.com. Dr. Gold has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned. Photos and other materials are available on the NEI Web site at www.nei.nih.gov/amblyopia.

Reference:

The Pediatric Eye Disease Investigator Group. A randomized trial of atropine vs. patching for treatment of moderate amblyopia in children. Arch Ophthalmol. 2002;120:268-278.