Screening for amblyogenic factors in preschool children with the retinomax hand-held refractor: do positive children have amblyopia and is treatment efficacious?
PURPOSE: To determine the visual acuity (VA) in a group of preschool children who were true positives for refractive screening (positive group) in order to compare it with the VA of a sample of children without any refractive anomaly (control group); also, to investigate if true-positive treated children can achieve the VA of the control group within what delay. METHODS: Fifty seven children without any refractive anomaly were tested with the VA child chart if the Nidek SCP 670 projector; 47 children presenting with the refractive anomalies were tested with the same chart. A Kruskal Wallis exact test for singly ordered tables were used to compare VA between those groups and a non-parametric Wilcoxon test for paired samples was used to compare pre- and post-treatment VA in 27 children of the positive group. The mean time necessary to achieve the post-treatment VA was calculated. RESULTS: Median VA: 20/20 in the control group, 20/33 in the positive group. The VA difference between the two pre- and post-treatment VA are highly significant. Among the 27 treated children, pre-treatment median VA was 20/50, post-treatment 20/20. The differences between the pre- and post-treatment VA was 9 months. CONCLUSION: The positive group had a significantly lower VA than the control group. In the treated group, treatment initiated at a mean age of 4 years resulted in an increase in VA to that of the control group after an average time of 9 months, encouraging early screening and treatment before VA is measureable in order to shorten this delay.