Sightsavers, 35 Perrymount Road, Haywards Heath, West Sussex RH16 3BW.
Middlesex University London.
Int Health. 2022 Apr 6;14(Suppl 1):i41-i48. doi: 10.1093/inthealth/ihab085.
Evidence indicates that school-based vision screening by trained teachers is an effective way of identifying and addressing potential vision problems in schoolchildren. However, inconsistencies have been reported in both the testing methods and accuracy of the screeners. This study assessed the prevalence of refractive errors and accuracy of screening by teachers in Grand Kru County, Liberia.
We conducted a retrospective analysis of data from four schools where, in February 2019, children were screened for refractive errors by trained teachers and then re-examined by ophthalmic technicians. One row of five optotypes of the Snellen 6/9 (0.2 logMar) scale (tumbling E chart) was used at a distance of 3 m. The prevalence of visual impairment and associations with sex, age and school were explored. Sensitivity, specificity and predictive values were calculated.
Data were available for 823 of 1095 eligible children with a mean age of 13.7 y (range 5-18) and male:female ratio of 1:0.8. Poor vision was identified in 24 (2.9%) children with no differences by either sex or age but small differences by school. Screening by teachers had a sensitivity of 0.25 (95% confidence interval [CI] 0.077 to 0.423) and a specificity of 0.996 (95% CI 0.992 to 1.000). Positive and negative predictive values were 0.667 (95% CI 0.359 to 0.975) and 0.978 (95% CI 0.968 to 0.988), respectively. The results were influenced by a high number of misclassifications in one of the four schools.
Teachers can be trained to conduct vision screening tests on schoolchildren to an acceptable level of accuracy, but strong monitoring and quality assurance systems should be built into screening programmes from the onset. In settings like Liberia, where many children do not attend school regularly, screening programmes should extend to community platforms to reach children out of school.
有证据表明，由经过培训的教师在学校进行视力筛查是识别和解决学童潜在视力问题的有效方法。然而，测试方法和筛查者的准确性存在不一致之处。本研究评估了利比里亚大克鲁县的屈光不正患病率和教师筛查的准确性。
我们对 2019 年 2 月在四所学校接受过培训的教师进行的视力筛查数据进行了回顾性分析，然后由眼科技术人员对这些儿童进行了复查。使用 Snellen 6/9（0.2 logMar）量表（滚动 E 图表）的一行 5 个视标，距离 3 米。探讨了视力障碍的流行率与性别、年龄和学校的关系。计算了敏感性、特异性和预测值。
共有 1095 名符合条件的儿童中的 823 名提供了数据，平均年龄为 13.7 岁（范围为 5-18 岁），男女比例为 1:0.8。24 名儿童视力不佳，无论性别或年龄均无差异，但不同学校之间存在差异。教师筛查的敏感性为 0.25（95%置信区间 [CI] 0.077 至 0.423），特异性为 0.996（95% CI 0.992 至 1.000）。阳性预测值和阴性预测值分别为 0.667（95% CI 0.359 至 0.975）和 0.978（95% CI 0.968 至 0.988）。结果受到四所学校之一中大量分类错误的影响。
可以培训教师对学童进行视力筛查测试，达到可接受的准确性水平，但应从一开始就建立监测和质量保证系统。在利比里亚等许多儿童不能正常上学的地方，筛查计划应扩展到社区平台，以覆盖校外儿童。
