Cordonnier M, Kallay O
Department of Ophthalmology, Erasmus University Hospital, Brussels, Belgium.
Strabismus. 2001 Jun;9(2):59-70. doi: 10.1076/stra.9.2.59.701.
To establish the results of refractive screening of preschool children with the hand-held autorefractor Retinomax under non-cycloplegic conditions, and to compare these results with those of photoscreening.
Among 1218 children undergoing non-cycloplegic refractive screening, 302 (25%) were also refracted under cycloplegia using the same refractor and were used as controls. Our criteria for a positive screening test were based on the spherical or cylinder values and were: myopia over 3D, astigmatism > or = 2D, spherical or cylindrical anisometropia > or = 1.5D, and hyperopia > or = 1.5D. Absolute myopia over 3D, absolute astigmatism > or = 2D, absolute anisometropia > or = 1.5D and absolute hyperopia > 3.5D were considered as true positives. The sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated within the group of controls for each refractive anomaly. On the basis of Bayes' theorem, these figures were then corrected to yield the true screening results that would be expected in a population without verification and selection bias. To determine the usefulness of this screening technique, the likelihood ratios for positive test results (+LR) were also calculated. The results of this screening in terms of sensitivity, specificity and predictive values were then compared with those of photoscreening.
The basic results of screening with the hand-held autorefractor were as follows: -EHyperopia: sensitivity 46%, specificity 97%, PPV 55%, NPV 96%, +LR 15; -EAstigmatism: sensitivity 37%, specificity 99%, PPV 69%, NPV 96%, +LR 37; -EAnisometropia: sensitivity 66%, specificity 93%, PPV 19%, NPV 99%, +LR 9; -EMyopia: sensitivity 87%, specificity 99%, PPV 33%, NPV 100%, +LR 87. The comparison with photoscreening revealed a similar performance when screening for hyperopia, but the hand-held autorefractor yielded much better figures when screening for astigmatism. In the case of myopia and anisometropia, the lack of consistent information concerning photoscreening invalidates any comparison.
The hand-held autorefractor Retinomax appears to have potential as a screening device. Our experience with the non-cycloplegic screening of preschool children for refractive anomalies indicates definite usefulness and reasonable accuracy of the Retinomax for detecting myopia, astigmatism and hyperopia. The weak point of this screening technique is the diagnosis of anisometropia, with only moderate utility and poor accuracy.
在非睫状肌麻痹条件下，使用手持自动验光仪Retinomax对学龄前儿童进行屈光筛查，并将结果与照片筛查结果进行比较。
在1218名接受非睫状肌麻痹屈光筛查的儿童中，302名（25%）也使用同一台验光仪在睫状肌麻痹下进行了验光，并作为对照。我们的筛查阳性标准基于球镜或柱镜值，具体如下：近视超过3D、散光≥2D、球镜或柱镜屈光参差≥1.5D以及远视≥1.5D。绝对近视超过3D、绝对散光≥2D、绝对屈光参差≥1.5D以及绝对远视超过3.5D被视为真阳性。针对每个屈光异常情况，在对照组中计算敏感性、特异性、阳性预测值和阴性预测值（PPV和NPV）。根据贝叶斯定理，对这些数据进行校正，以得出在无验证和选择偏倚人群中预期的真实筛查结果。为了确定这种筛查技术的实用性，还计算了阳性检测结果的似然比（+LR）。然后将这种筛查在敏感性、特异性和预测值方面的结果与照片筛查的结果进行比较。
手持自动验光仪的筛查基本结果如下：远视：敏感性46%，特异性97%，PPV 55%，NPV 96%，+LR 15；散光：敏感性37%，特异性99%，PPV 69%，NPV 96%，+LR 37；屈光参差：敏感性66%，特异性93%，PPV 19%，NPV 99%，+LR 9；近视：敏感性87%，特异性99%，PPV 33%，NPV 100%，+LR 87。与照片筛查的比较显示，在筛查远视时表现相似，但在筛查散光时，手持自动验光仪得出的数据要好得多。在近视和屈光参差方面，由于缺乏关于照片筛查的一致信息，无法进行任何比较。
手持自动验光仪Retinomax似乎有作为筛查设备的潜力。我们对学龄前儿童进行非睫状肌麻痹屈光异常筛查的经验表明，Retinomax在检测近视、散光和远视方面具有明确的实用性和合理的准确性。这种筛查技术的弱点在于屈光参差的诊断，其效用一般且准确性较差。
