Abstract
Abstract: :
Purpose:To test the hypothesis that preschool vision screening by orthoptists improves visual outcome in children with amblyopia, as there are no randomised trials that address this question. Methods:A randomised controlled trial (RCT) compared intensive orthoptic screening (at 8, 12, 18, 25, 31 and 37 months) with intermediate-level orthopic screening (at 37 months only) or no orthoptic screening.This RCT was nested in a birth cohort study. The outcome was assessed when the children were 7 years old. Results:Amblyopia was less prevalent in the intensive group than in the intermediate group (0.6% vs. 1.8%; p = 0.02) or the no screening group (0.6% vs. 1.2%; p = 0.70). Similar proportions of children had been treated for amblyopia in each group. In comparison with the intensive group, the likelihood (OR: 95% CI) of persistent amblyopia despite treatment was 4.1 (1.1 - 16.6)times greater for the intermediate group and 7.0 (1.3 - 38.6) times greater for the no screening group. Median acuities in amblyopic eyes at 7 years in the 3 groups were 0.12, 0.19 and 0.27 LogMAR units respectively (p = 0.04) Conclusion:Treatment for amblyopia was more effective after repeated orthoptic screening between 8 - 37 months as compared with similar screening at 37 months only, which in turn was associated with more effective treatment than was no orthoptic screening. These data support the hypothesis that early treatment leads to a better outcome than later treatment.
Keywords: 313 amblyopia • 575 screening for ambylopia and strabismus • 620 visual acuity