Jayatunga R, Sonksen P M, Bhide A, Wade A
Sandwell District General Hospital, West Bromwich, West Midlands.
Dev Med Child Neurol. 1995 Jun;37(6):515-27. doi: 10.1111/j.1469-8749.1995.tb12039.x.
492 five to nine year old children participated in a study of the ability of three tests of linear acuity --the Sonksen-Silver Acuity System (SSAS), the Sheridan Gardiner 7-letter chart and the Keelers MK2 chart to identify children requiring specialist visual examination. The ability of the three tests to detect children with visual defects at 6m and of the SSAS in several test test conditions (3m and 6m, monocular and binocular) was investigated at two acuity levels for referral (3/4.5 or 6/9 and 3/6 or 6/12). Although specificity was very high for all tests and test conditions using a 3/6 or 6/12 cut-off for referral, the sensitivity and yield were disappointingly low; higher levels of the latter were achieved at the expense of a degree of specificity using a 3/4.5 or 6/9 cut off. Similarly, sensitivity and yield were greater for the monocular than binocular condition and for the 6m than 3m condition. A test of near vision (SSAS) did not detect any children not already identified by a distance measure. The optometric and developmental rationale behind the differences is discussed.
492名5至9岁的儿童参与了一项研究，该研究旨在探讨三种线性视力测试——桑克森-西尔弗视力系统（SSAS）、谢里丹·加德纳7字母视力表和基勒斯MK2视力表——识别需要进行专业视力检查儿童的能力。研究在两个转诊视力水平（3/4.5或6/9以及3/6或6/12）下，调查了这三种测试在6米距离检测视力缺陷儿童的能力，以及SSAS在几种测试条件（3米和6米、单眼和双眼）下的检测能力。尽管对于所有测试和使用3/6或6/12转诊临界值的测试条件，特异性都非常高，但敏感性和检出率却低得令人失望；使用3/4.5或6/9临界值时，虽然后者水平更高，但牺牲了一定程度的特异性。同样，单眼条件下的敏感性和检出率高于双眼条件，6米距离时高于3米距离。一项近视力测试（SSAS）未检测出任何未被远距离测量法识别出的儿童。文中讨论了这些差异背后的验光和发育原理。
