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Alaska Blind Child Discovery

A cooperative, charitable research project to Eliminate Amblyopia Blindness in Alaska
 

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We present the methodology of a population-based Randomised Controlled Trial, (Avon Longitudinal Study of Parents and Children (ALSPAC) comparing an intensive programme of primary preschool vision screening by orthoptists with the usual non-specialist screening. The aims of the trial are to compare the effectiveness and costs of intensive orthoptic screening with non-specialist measures. The orthoptic screening programme will be evaluated both as a composite package and in terms of the screening value of the individual tests at specific ages. This trial is nested within a large population-based longitudinal study. Additional demographic and developmental data on the children in the trial are therefore available. The results of the trial will be used to help clarify which methods of preschool ophthalmic population screening are best in terms of disease detection and cost efficiency.( Williams C, Harrad RA, Harvey I, Frankel S, Golding J. Methodology for a randomised controlled trial of preschool vision screening. A new approach with the 'ALSPAC' project. Ophthalmic Epidemiol 1996;3(2):63-76)

We present the methodology of a population-based Randomised Controlled Trial, comparing an intensive programme of primary preschool vision screening by orthoptists with the usual non-specialist screening. The aims of the trial are to compare the effectiveness and costs of intensive orthoptic screening with non-specialist measures. The orthoptic screening programme will be evaluated both as a composite package and in terms of the screening value of the individual tests at specific ages. This trial is nested within a large population-based longitudinal study. Additional demographic and developmental data on the children in the trial are therefore available. The results of the trial will be used to help clarify which methods of preschool ophthalmic population screening are best in terms of disease detection and cost efficiency.( Williams C, Harrad RA, Harvey I, Sparrow JM. Screening for amblyopia in preschool children: results of a population- based, randomised controlled trial. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood. Ophthalmic Epidemiol 2001;8(5):279-95.)

Objective: To assess the effectiveness of early treatment for amblyopia in children. Design: Follow up of outcomes of treatment for amblyopia in a randomised controlled trial comparing intensive orthoptic screening at 8, 12, 18, 25, 31, and 37 months (intensive group) with orthoptic screening at 37 months only (control group). Setting: Avon, southwest England. Participants: 3490 children who were part of a birth cohort study. Main outcome measures: Prevalence of amblyopia and visual acuity of the worse seeing eye at 7.5 years of age. Results: Amblyopia at 7.5 years was less prevalent in the intensive group than in the control group (0.6% v 1.8%; P=0.02). Mean visual acuities in the worse seeing eye were better for children who had been treated for amblyopia in the intensive group than for similar children in the control group (0.15 v 0.26 LogMAR units; P<0.001). A higher proportion of the children who were treated for amblyopia had been seen in a hospital eye clinic before 3 years of age in the intensive group than in the control group (48% v 13%; P=0.0002). Conclusions: The intensive screening protocol was associated with better acuity in the amblyopic eye and a lower prevalence of amblyopia at 7.5 years of age, in comparison with screening at 37 months only. These data support the hypothesis that early treatment for amblyopia leads to a better outcome than later treatment and may act as a stimulus for research into feasible screening programmes.( Williams C, Northstone K, Harrad RA, Sparrow JM, Harvey I. Amblyopia treatment outcomes after screening before or at age 3 years: follow up from randomised trial. BMJ 2002;324(7353):1549.)

BACKGROUND/AIMS: Preschool screening for amblyopia has controversially been abandoned in some localities within the United Kingdom, on the basis that there is no clear evidence of benefit to support its continuation. Data collected within a birth cohort study were used to examine visual outcomes at 7(1/2) years in children who did or did not receive preschool vision screening. METHODS: Monocular logMAR visual acuity with and without a pinhole was assessed by orthoptists. Contemporary records were used to identify children who had been offered and/or received preschool screening. RESULTS: Of 6081 children, 24.9% had been offered preschool screening and 16.7% had attended. The prevalence of amblyopia was approximately 45% lower in the children who received preschool screening than in those who did not (1.1% v 2.0%, p = 0.05). The mean acuity in the worse seeing eyes after patching treatment was better for amblyopic children who received preschool screening than for those who did not; 0.14 v 0.20 logMAR (p <0.001). These effects did not persist in an intention to screen analysis. CONCLUSIONS: Preschool screening at 37 months was associated with an improved treatment outcome for individuals with amblyopia. However, the improvement was clinically small and disappeared when considering all children offered screening rather than only those who received it. Further research is needed into improving the effectiveness of vision screening for preschool children, while in the interim these data do not conflict with current recommendations for school entry screening by orthoptists.( Williams C, Northstone K, Harrad R, Sparrow JM, Harvey I, ALSPAC-Study-Team. Amblyopia treatment outcomes after preschool screening v school entry screening: observational data from a prospective cohort study. Br J Ophthalmol 2003;87(8):988-993.)

PURPOSE: To investigate whether wearing glasses, having manifest strabismus, or having a history of wearing an eye patch predisposes preadolescent children to being victimized more frequently at school and whether the impact may be different on boys than on girls. METHODS: Data were examined on 6536 children from the Avon Longitudinal Study of Parents and Children (ALSPAC) based in the United Kingdom. At 7.5 years, the children undertook a detailed eye examination by orthoptists, including a cover test and visual acuity assessment. At 8.5 years, trained psychologists assessed the children's bullying involvement as either victim or perpetrator for overt and relational bullying, in a standard interview. RESULTS: Children currently wearing glasses or with a history of wearing eye patches were 35% to 37% more likely to be victims of physical or verbal bullying, even after adjustment for social class and maternal education. No interactions were found between sex and visual problems in the prediction of bullying. CONCLUSIONS: For those children who require glasses, opticians should be aware of the risks of bullying, and strategies should be developed and discussed that help reduce their vulnerability.( Horwood J, Waylen A, Herrick D, Williams C, Wolke D. Common visual defects and peer victimization in children. Invest Ophthalmol Vis Sci 2005;46(4):1177-81.)
 
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