UBC Theses and Dissertations
Comparison of three vision screening measures for use with primary school students Reynolds, Jeanette
Literature regarding the vision care needs of school children indicates that a variety of visual anomalies occur in sufficient numbers among children to warrant recommendation of a comprehensive school vision screening programme. A quasi-experimental study was conducted to investigate the referral efficacy (accuracy) of the Keystone Telebinocular (KTT), the Modified Telebinocular (MTT), and the Snellen against a standard optometric exam. Sixty children, aged 6-0 to 9-11, who had scheduled appointments with one of five optometrists in Coquitlam, Surrey, and White Rock, British Columbia, were administered the three screening measures, a letter identification test, and a standard optometric examination. Subjects' performance on each screening measure was compared to their performance on the standard optometric exam and categorized as a positive referral, a negative referral, an overreferral, or an underreferral. Chi-square and phi coefficient analyses were used to make the following comparisions: 1) the referral efficacy of the MTT versus that of the KTT, 2) the referral efficacy of the MTT versus that of the Snellen, 3) the referral efficacy of the KTT versus that of the Snellen. The MTT had greater efficacy than the Snellen for positive referrals (X² ( 1 ) = 7 . 000 , p<.0l) and underref errals (X² ( 1 )=8 . 909, p<.0l). The Snellen had greater efficacy than either the MTT (X² (1 ) =7 . 363 , p<.01 ) or the KTT (X² (1)=5 . 444, p<.05) for overreferrals. Overreferrals and underreferrals were both undesirable, with underreferrals being the more serious. In addition to statistical performance, the suitability of test requirements for the target population and ease of administration were also considered in evaluating the usefulness of a screening measure. When all the factors of vision screening were considered, the MTT proved to be the superior procedure for identifying children requiring professional care.
Item Citations and Data