An Evaluation of Treatment of Amblyopia in Children 7 To <18 Years Old

Most eye care practitioners believe that there is an age beyond which attempting to treat amblyopia is futile. It is generally held that the response to treatment is best when it is instituted at an early age and is poor when attempted after eight years of age. There has not been a prospective clinical trial conducted with appropriate rigor that has evaluated the effect of treatment of amblyopia in children aged 7 years or older. Although available data on the efficacy of amblyopia treatment of older children are limited, there is reason to believe from clinical observations and published case series that treatment could have benefit. In a pilot study of patients 10 to <18 years old with amblyopia, we found that 37 percent of 52 patients showed improvement in the amblyopic eye acuity of 2 or more lines after treatment with part-time patching. However, without a concurrent randomized control group, the results are not conclusive. Although the literature and our pilot study provide support that amblyopia can be improved with treatment, neither the response rate to treatment nor the recidivism rate after cessation of treatment can be well defined. Despite the evidence that amblyopia therapy can be effective in older children, many clinicians do not attempt treatment under the assumption that it will be unsuccessful. Therefore, a clinical trial is needed to provide the requisite data to establish clinical practice guidelines for the treatment of amblyopia in older children. In addition to its importance for patient management, the trial's results will meet the demand for cost effectiveness by health maintenance organizations, large employers, and insurers.

The study is a randomized trial comparing patients treated with spectacles only (Control Group) to patients undergoing active treatment (patching, near activities while patching, and atropine for children under the age of 13) in addition to spectacles (Active Treatment Group). It will enroll a minimum of 90 patients in each of the age groups of 7 to <9, 9 to <11, 11 to <13, and 13 to <18 years old. Patients have follow up visits every 6 weeks (up to a maximum of 24 weeks) until they are classified as either responders or nonresponders based on amblyopic eye visual acuity. At the end of the randomized trial:

• Patients who did not respond to treatment end follow up.
• Patients who responded to treatment continue in their respective treatment groups until visual acuity stops improving.

Once there is no further improvement in visual acuity:

• Patients in the Control Group end follow up
• Patients in the Active Treatment Group discontinue active treatment and have follow up visits at 13 weeks, 26 weeks, and 52 weeks timed from treatment discontinuation.

Inclusion criteria

• Patients must be aged 7 to <18 years and have amblyopia associated with strabismus, anisometropia, or both.
• Visual acuity in the amblyopic eye must be 20/40 to 20/400 inclusive and visual acuity in the sound eye must be 20/25 or better.

Exclusion criteria

• Patients must not have received amblyopia treatment (other than spectacles) in the past month or more than one month of amblyopia treatment in the last 6 months.