Spectacle correction attains 20/25 in children with bilateral refractive amblyopia

Treatment of bilateral refractive amblyopia, primarily with only spectacle correction, improves binocular visual acuity in children aged 3 to less than 10 years, with most achieving 20/25 acuity or better within 1 year, reported David Wallace, MD, for the Pediatric Eye Disease Investigator Group. Dr. Wallace is from the Department of Ophthalmology, Duke University, Durham, NC.

"Bilateral refractive amblyopia can develop in children with large amounts of uncorrected hypermetropia and/or astigmatism and is generally treated with the appropriate correction," Dr. Wallace said. "The prevalence of bilateral refractive amblyopia is about 0.5%."

A total of 113 children were enrolled prospectively in the study that was conducted at 27 sites. The study sought to determine both the amount and the time course of the improvement in binocular visual acuity in the patient group. Inclusion criteria included untreated bilateral refractive amblyopia that was defined as 20/40 to 20/400 best-corrected binocular visual acuity in each eye and binocularly and 4 D or greater of hypermetropia, and/or 2 D or more of astigmatism in each eye.

The children received optimal spectacle correction and were followed for 1 year. They were evaluated at baseline and at 5, 13, 26, and 52 weeks. Treatment with atropine or patching was done at the discretion of the treating physician, Dr. Wallace said.

During the follow-up period, 96 patients (85%) were treated with spectacle correction alone and 17 patients (15%) were treated with patching or atropine and spectacle correction. A total of 109 patients completed the 52-week visit.

Dr. Wallace reported that spectacle compliance was excellent at each visit in 68% of children, with excellent defined as spectacles that were worn 75% to 100% of waking hours.

"At 1 year the mean binocular best-corrected visual acuity improved from a mean baseline logMAR visual acuity of 0.5 to 0.11 for a mean improvement of 3.9 lines (95% confidence interval, 3.5 to 4.2)," he reported.

Investigators found that the worse the baseline binocular visual acuity (20/100 to 20/320), the greater was the improvement in the visual acuity, i.e., 6.3 lines (confidence interval, 4.9 to 7.3). Those patients with better baseline acuity improved less.

"Treatment of bilateral refractive amblyopia with spectacle correction substantially improves the binocular visual acuity in children aged 3 to less than 10 years," Dr. Wallace concluded. "Most of the children in the study cohort improved to 20/25 or better after 1 year. These improvements in vision and stereopsis were generally achieved with spectacles alone."