Bailey R N
University of Houston, College of Optometry, Houston, Texas, USA.
Optom Vis Sci. 1998 Sep;75(9):682-91. doi: 10.1097/00006324-199809000-00024.
The purpose of this study is to assess the predictive ability of the test-positive findings of an elementary school vision screening program, conducted by 2nd-year optometry students, in identifying children with eye or vision disorders.
A modified version of the Modified Clinical Technique (MCT) vision screening was administered to elementary children from a below-average socioeconomic neighborhood in Houston, Texas. Comprehensive eye and vision examinations were provided to the available children who failed the vision screening. The screening was administered by groups of 2nd-year optometry students with the assistance of a 4th-year optometry student, and supervised by a faculty member licensed to practice optometry. The follow-up examinations were provided by supervised 4th-year optometry students in a clinical setting based at the elementary school. Positive predictive values calculated from the screening and examination findings estimate the probability that a failure on one or more of the screening tests would identify children with eye or vision disorders.
Sixty-nine percent of the test-positive children examined were found to be true positives by the criteria developed in a study of vision screening methods in Orinda, California from 1954 through 1956.
The predictive ability of this study's test-positive findings for identifying eye and vision disorders was found to be less than the predictive ability of the Orinda Study findings. This reduced predictive ability of the present study resulted in a larger number of children being overreferred for examinations than had occurred in the Orinda Study. The reduction in the ability of the test-positive findings of the current study's screening program to identify accurately children with eye and vision problems is most likely due to the limited experience of the optometry students conducting the screening program. The inability of this retrospective study to evaluate the accuracy of the test-negatives is a major limitation in assessing the total effectiveness of this vision screening program. Although the present study may indicate some value in optometry students conducting elementary vision screening programs, a prospective study which could assess the predictive ability of both test-positive and test-negative findings, as well as determine the sensitivity and specificity of the screening program, is needed to assess more fully the effectiveness of school vision screening programs using professional students.
本研究旨在评估由二年级验光专业学生开展的小学视力筛查项目的检测阳性结果在识别患有眼部或视力障碍儿童方面的预测能力。
对德克萨斯州休斯顿一个社会经济水平低于平均水平社区的小学生进行改良版的改良临床技术（MCT）视力筛查。为视力筛查未通过的儿童提供全面的眼部和视力检查。筛查由二年级验光专业学生在一名四年级验光专业学生的协助下分组进行，并由一名有验光执业资格的教员监督。后续检查由四年级验光专业学生在以该小学为基地的临床环境中进行监督。根据筛查和检查结果计算的阳性预测值估计了一项或多项筛查测试未通过会识别出患有眼部或视力障碍儿童的概率。
根据1954年至1956年在加利福尼亚州奥林达进行的一项视力筛查方法研究制定的标准，在接受检查的检测阳性儿童中，69%被发现为真正的阳性。
本研究检测阳性结果在识别眼部和视力障碍方面的预测能力低于奥林达研究结果的预测能力。本研究预测能力的降低导致被过度转诊进行检查的儿童数量比奥林达研究中更多。本研究筛查项目检测阳性结果准确识别眼部和视力问题儿童能力的下降很可能是由于进行筛查项目的验光专业学生经验有限。这项回顾性研究无法评估检测阴性结果的准确性是评估该视力筛查项目整体有效性的一个主要局限。尽管本研究可能表明验光专业学生开展小学视力筛查项目有一定价值，但需要一项前瞻性研究来更全面地评估使用专业学生的学校视力筛查项目的有效性，该研究能够评估检测阳性和检测阴性结果的预测能力，以及确定筛查项目的敏感性和特异性。
