儿童屈光不正及近视的视力筛查标准

Cutoff point of visual acuity to screen refractive error or myopia in Chinese children

目的 探讨快速筛查儿童屈光不正及近视的视力标准.方法 横断面调查研究.使用2002年10月至2003年1月中山大学中山眼科中心对广州市荔湾区进行的屈光不止研究（RESC）数据,检查包含裸眼视力（ETDRS视力表）、散瞳下自动电脑验光（ARK-30;Nidek Corp.）及眼部健康检查.屈光不正定义为SE≤-0.50 D、SE≥＋2.00 D或散光≤-1.00 D;近视定义为：等效球镜度（SE）≤-0.50 D、或SE≤-0.75 D、或SE≤-1.00 D;统计灵敏度、特异度、阳性和阴性预测值,并作ROC曲线图.结果 共统计3 715名7～15岁儿童数据.屈光不正ROC曲线图显示灵敏度,特异度都相对高的视力为0.625,其灵敏度、特异度、阳性和阴性预测值分别为71.7％、93.3％、92.9％和72.9％.近视ROC曲线图显示灵敏度、特异度都相对高的视力为0.5.等效球镜度≤-0.50、-0.75或-1.00 D的灵敏度分别为66.3％、73.5％和80.7％,特异度分别为94.3％、94.0％和93.5％,阳性预测值分别为89.7％、88.0％和86.3％,阴性预测值分别为78.9％、85.4％和90.5％.结论 对于7～15岁儿童,0.625为筛查屈光不正的视力截点,0.5为筛查高于-1.00D近视的视力截点.

Objective To determine the cutoff point of visual acuity to screen refractive error or myopia in children. Methods This was a cross-sectional research. The database of the RESC （Refractive Error Study in Children） were used which were collected from October 2002 to January 2003. The examination included visual acuity measurement （ETDRs visual acuity chart）, auto refraction （ARK-30; Nidek Corp.） and ocular health examination. The definition of refractive error was SE~〈-0.50 D, SE~〉＋2.00 D or cylinder power ~〈-1.00 D. The sensitivity, specificity, and predictive values were calculated using each patient as a case; a receiver operator curve was plotted. Myopia was defined as： spherical equivalent （SE）〈^-0.50 D or SE〈^-0.75 D or SE~〈-I.00 D. Results The data of 3 715 cases 7-15 years old subjects＇ were analyzed. A satisfactory sensitivity/specificity profile was obtained which show 0.625 was the cutoff point for refractive error. The sensitivity, specificity, positive and negative predictive values were 71.7%, 93.3%, 92.9%, 72.9%, respectively. And 0.5 was the best cutoff point under three different myopia definitions. The sensitivity for SE~〈-0.50 D, -0.75 D or -1.00 D were 66.3%, 73.5%, 80.7%, respectively. The specificity were 94.3%, 94.0% and 93.5%, respectively. The positive predictive values were 89.7%, 88.0% and 86.3%, and the negative predictive values were 78.9%, 85.4%, 90.5%. Conclusion 0.625 is advised to screen refractive error, while 0.5 is advised to screen potential myopia subjects who aged 7 to 15.