目的　探讨小儿内眦指数的正常值及内眦指数对小儿某些智力低下疾病的诊断价值。方法　测量 0～ 12岁正常儿 36 0例和 6月～ 6岁智力障碍患儿 5 2例的头围、内眦距、外眦距 ,用内眦距 /外眦距得出内眦指数Ⅰ。用内眦距 /头围得出内眦指数Ⅱ。各组参数进行统计学分析。结果　正常儿内眦指数Ⅰ 0 .34± 0 .0 3,内眦指数Ⅱ 0 .0 6 8± 0 .0 0 8;2 1-三体综合征内眦指数Ⅰ 0 .5 1± 0 .0 2 ,内眦指数Ⅱ 0 .0 91± 0 .0 0 4,与正常儿比较差异非常显著 (P <0 .0 1) ,克汀病内眦指数Ⅰ 0 .48± 0 .0 4,差异非常显著 (P <0 .0 1) ;内眦指数Ⅱ 0 .0 96± 0 .0 0 7,差异显著 (P <0 .0 5 ) ;脑发育不全内眦指数Ⅰ 0 .5 1± 0 .0 7,差异显著 (P <0 .0 5 ) ;内眦指数Ⅱ 0 .0 89± 0 .0 0 8,差异不显著 (P >0 .0 5 ) ;脑病及颅内出血后遗症内眦指数Ⅰ 0 .38± 0 .0 6 ,内眦指数Ⅱ 0 .0 6 4± 0 .0 0 4,差异不显著 (P >0 .0 5 )。结论　内眦指数Ⅰ和内眦指数Ⅱ既可反映内眦距离又不受年龄影响 ,尤以指数Ⅰ更具临床实用价值。

Objective To explore the normal value of inner canthal index in children and the diagnositic value of inner canthal index measurements in children with mental retardation. Methods Head circumference and width of the inner and external canthus were measured in 360 normal children aged 0～12, years and in 52 children with mental retadation aged from 6 months to 6 years. Two indices were studied: Index Ⅰ=the ratio of the inner canthus to the external canthus and Index Ⅱ=the ratio of the inner canthus to head circumference. Results In the normal children Index Ⅰ was 0.34 ± 0.03 and Index Ⅱ was 0.068 ± 0.008 . In children with Trisomy 21, Index Ⅰ was 0.51 ± 0.02 and Index Ⅱ was 0.091 ± 0.004 (P< 0.01 vs. control). In infants with cretinism, Index Ⅰ was 0.48 ± 0.04 (P< 0.01 vs. control) and Index Ⅱ was 0.096 ± 0.007 (P< 0.05 vs. control). Children with brain dysplasia had an Index Ⅰ of 0.51 ± 0.07 (P< 0.05 vs. control); and they had an index Ⅱ of 0.089 ± 0.008 . There was no significant difference vs control (P> 0.05 ). No significant differences in Index Ⅰ ( 0.38 ± 0.06 ) or Index Ⅱ ( 0.064 ± 0.004 ) were noted in infants with intracranial hemorrhage. (P> 0.05 ) Conclusions Index Ⅰ and Index Ⅱ can reflect the width of the inner canthus and they are not influenced by age. Index Ⅰ may have a more important value than Index Ⅱ in the clinical application.