Lea Symbols与Tumbling E视力表在学龄前儿童视力检查中的应用

The use of Lea Symbols chart and Tumbling E chart in preschool children's vision examination

目的比较LeaSymbols视力表与TumblingE视力表在学龄前儿童中视力的检测率、视力值和双眼间视力差异。方法对温州市某幼儿园一小班24名36～50(平均43.2±3.71)个月的儿童以随机顺序先后用LeaSymbols与TumblingE视力表检查单眼视力,视力值用logMAR记录方法来表示,用logMAR单位记录双眼视力差异。结果Leasymbols视力表的检测率为96%,Tum-blingE视力表的检测率为71%,其中33只眼能配合查Leasymbols与TumblingE,TumblingE的视力为0.26±0.10,Leasymbols的视力为0.19±0.10,两者呈线形相关(相关系数r=0.76),两者作配对t检验有显著性差异(t=6.068,p<0.0001),16名儿童用LeaSymbols测得的双眼视力差别为-0.004±0.065,用TumblingE测得的双眼视力差别为-0.019±0.067,两者呈线形相关(相关系数r=0.65),统计学分析两者无显著性差异(p=0.296)。结论Leasymbols视力表检查学龄前儿童视力特别是3～4周岁的儿童检测率高,LeaSymbols与TumblingE视力表一样能够很好地反映双眼间视力的差别,但与TumblingE视力表相比,LeaSymbols视力表存在过高估计视力的可能。视力的测定是个心理物理学过程,对于学龄前儿童,我们不能简单地根据视力小于0.8判断其弱视,而是要从儿童的认知水平来考虑。

Objective To establish normal visual acuity for three to four years old children and to compare testability, visual acuity and inter-eye difference using Lea Symbols chart and Tumbling E chart. Methods 24 preschool-aged children between 36 and 50 months（mean=43.2,standard deviation=3.71） were recruited from one kid-garden in Wenzhou. Each subject was measured the acuity of the right eye and left eye tested with the Lea Symbols chart and Tumbling E chart in random order. Outcome measures were monocular logarithm of the minimum angle of resolution（logMAR） visual acuity and inter-eye acuity difference in IogMAR units for each test. Results 96% of children were able to complete monocular test with Lea Symbols chart, but the testability of Tumbling E chart was 71%.33 eyes cooperate to test with Lea Symbols chart and Tumbling E chart, Mean（ ± SD） visual acuity obtained with the Lea Symbols chart was 0.19 ± 0.10, Mean（ ± SD） visual acuity obtained with the Tumbling E chart was 0.26 ± 0.10, there was significant difference（t=6.068, p〈0.0001）,but the correlation between acuity results obtained with two charts was high（r=0.76）.There was no significant difference（pffi0.296） in inter-eye acuity difference measured with Lea Symbols chart（-0.004 ± 0.065） and Tumbling E chart（-0.019 ± 0.067）in 16 children, but the correlation coefficient was high（r--0.65）. Conclusions Testability rates was better for preschool-aged children using Lea Symbols chart, Lea Symbols chart provides a better measure of inter-eye acuity difference that is similar to that obtained with Tumbling E chart, but may overestimate the acuity score measured by the Tumbling E chart. The measureinent of visual acuity is a psychophysical process. For preschool-aged children, we can not diagnosis amblyopia if his best correct.vision does not reach 0.8, we must consider the corresponding cognition of the children.