Natural history of amblyopia untreated owing to lack of compliance

Aims-A prospective study of the efficacy of amblyopia treatment in preschoo l children has recently been called for, requiring an untreated control gro up. The present study assessed data fi om patients with amblyopia untreated owing to lack of compliance, or with amblyopia risk factors, to determine outcome. Methods-Longitudinal data were obtained from 18 4-6 year old patients who h ad initially been screened for amblyopia, strabismus, and/or bilateral refr active error, failed to comply with prescribed treatment, and in whom ambly opia was detected at a rescreening approximately a year later. Thc data fro m three previous studies comparing outcome of patients compliant and non-co mpliant with amblyopia treatment were also reanalysed. Results-One child of the 18, who wore glasses sporadically, showed some imp rovement in visual acuity in the amblyopic eye. Otherwise, no child showed an improvement, and seven of the 17 (41%) for whom visual acuities were ava ilable at both screenings showed a deterioration of visual acuity in the am blyopic eye, including three who apparently developed amblyopia for the fir st time. A child with an ametropic risk factor for amblyopia whose visual a cuity was not obtained at the first screening and who was largely noncompli ant presented with amblyopia at the second screening. The reanalysed data f rom the three previous studies demonstrated a significantly poorer visual a cuity outcome in the amblyopic eye in the noncompliant patient groups than in the compliant groups ht each study. Conclusion-Preschool children with amblyopia or its risk factors are at ris k of having the current amblyopia deteriorate, or of developing amblyopia, if not treated. These results raise questions about the ethical acceptabili ty of a prospective study of amblyopia treatment at these ages.