RT Journal Article SR Electronic T1 Natural history of amblyopia untreated owing to lack of compliance JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 582 OP 587 DO 10.1136/bjo.83.5.582 VO 83 IS 5 A1 Kurt Simons A1 Mark Preslan YR 1999 UL http://bjo.bmj.com/content/83/5/582.abstract AB AIMS A prospective study of the efficacy of amblyopia treatment in preschool children has recently been called for, requiring an untreated control group. The present study assessed data from 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 had initially been screened for amblyopia, strabismus, and/or bilateral refractive error, failed to comply with prescribed treatment, and in whom amblyopia was detected at a rescreening approximately a year later. The data from three previous studies comparing outcome of patients compliant and non-compliant with amblyopia treatment were also reanalysed. RESULTS One child of the 18, who wore glasses sporadically, showed some improvement in visual acuity in the amblyopic eye. Otherwise, no child showed an improvement, and seven of the 17 (41%) for whom visual acuities were available at both screenings showed a deterioration of visual acuity in the amblyopic eye, including three who apparently developed amblyopia for the first time. A child with an ametropic risk factor for amblyopia whose visual acuity was not obtained at the first screening and who was largely non-compliant presented with amblyopia at the second screening. The reanalysed data from the three previous studies demonstrated a significantly poorer visual acuity outcome in the amblyopic eye in the non-compliant patient groups than in the compliant groups in each study. CONCLUSION Preschool children with amblyopia or its risk factors are at risk of having the current amblyopia deteriorate, or of developing amblyopia, if not treated. These results raise questions about the ethical acceptability of a prospective study of amblyopia treatment at these ages.